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  • 101.
    Midander, Klara
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Elihn, K.
    Stockholm Univ, Sweden .
    Wallén, A.
    Stockholm Univ, Sweden .
    Belova, Liubov
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Teknisk materialfysik.
    Borg-Karlsson, Anna Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Odnevall Wallinder, Inger
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Characterisation of nano- and micron-sized airborne and collected subway particles, a multi-analytical approach2012Ingår i: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 427, s. 390-400Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Continuous daily measurements of airborne particles were conducted during specific periods at an underground platform within the subway system of the city center of Stockholm, Sweden. Main emphasis was placed on number concentration, particle size distribution, soot content (analyzed as elemental and black carbon) and surface area concentration. Conventional measurements of mass concentrations were conducted in parallel as well as analysis of particle morphology, bulk- and surface composition. In addition, the presence of volatile and semi volatile organic compounds within freshly collected particle fractions of PM 10 and PM 2.5 were investigated and grouped according to functional groups. Similar periodic measurements were conducted at street level for comparison.The investigation clearly demonstrates a large dominance in number concentration of airborne nano-sized particles compared to coarse particles in the subway. Out of a mean particle number concentration of 12000 particles/cm 3 (7500 to 20000 particles/cm 3), only 190 particles/cm 3 were larger than 250nm. Soot particles from diesel exhaust, and metal-containing particles, primarily iron, were observed in the subway aerosol. Unique measurements on freshly collected subway particle size fractions of PM 10 and PM 2.5 identified several volatile and semi-volatile organic compounds, the presence of carcinogenic aromatic compounds and traces of flame retardants.This interdisciplinary and multi-analytical investigation aims to provide an improved understanding of reported adverse health effects induced by subway aerosols.

  • 102. Moreira, Xoaquin
    et al.
    Lundborg, Lina
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Zas, Rafael
    Carrillo-Gavilan, Amparo
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Sampedro, Luis
    Inducibility of chemical defences by two chewing insect herbivores in pine trees is specific to targeted plant tissue, particular herbivore and defensive trait2013Ingår i: Phytochemistry, ISSN 0031-9422, E-ISSN 1873-3700, Vol. 94, s. 113-122Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    There is increasing evidence that plants can react to biotic aggressions with highly specific responses. However, few studies have attempted to jointly investigate whether the induction of plant defences is specific to a targeted plant tissue, plant species, herbivore identity, and defensive trait. Here we studied those factors contributing to the specificity of induced defensive responses in two economically important pine species against two chewing insect pest herbivores. juvenile trees of Pious pinaster and P. radiata were exposed to herbivory by two major pest threats, the large pine weevil Hylobius abietis (a bark-feeder) and the pine processionary caterpillar Thaumetopoea pityocampa (a folivore). We quantified in two tissues (stem and needles) the constitutive (control plants) and herbivore-induced concentrations of total polyphenolics, volatile and non-volatile resin, as well as the profile of mono- and sesquiterpenes. Stem chewing by the pine weevil increased concentrations of non-volatile resin, volatile monoterpenes, and (marginally) polyphenolics in stem tissues. Weevil feeding also increased the concentration of non-volatile resin and decreased polyphenolics in the needle tissues. Folivory by the caterpillar had no major effects on needle defensive chemistry, but a strong increase in the concentration of polyphenolics in the stem. Interestingly, we found similar patterns for all these above-reported effects in both pine species. These results offer convincing evidence that induced defences are highly specific and may vary depending on the targeted plant tissue, the insect herbivore causing the damage and the considered defensive compound.

  • 103. Mozuraitis, R.
    et al.
    Buda, V.
    Jonusaite, V.
    Borg-Karlson, Anna-Karin
    KTH, Tidigare Institutioner                               , Kemi.
    Noreika, R.
    Sex pheromones of Phyllonorycter acerifoliella and Ph. heegerella and communication peculiarities in three species of leafmining moths2000Ingår i: Entomologia Experimentalis et Applicata, ISSN 0013-8703, E-ISSN 1570-7458, Vol. 94, nr 1, s. 15-23Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Females of the leaf miner moth Phyllonorycter acerifoliella (Z.) [=Ph. sylvella (Hw.)] and Ph. heegerella (Z.) (Lepidoptera: Gracillariidae: Lithocolletinae) release their sex pheromone at the beginning of photophase. The periodicity of the 'calling' behaviour of Ph. acerifoliella females was established. Three compounds from calling virgin Ph. heegerella females were collected by the Solid Phase Micro Extraction (SPME) technique and identified as (Z)-8-tetradecenyl acetate (Z8-14:OAc), tetradecyl acetate (14:OAc) and (Z)-8-tetradecenol (Z8-14:OH) in the ratio (88 +/- 3):(2 +/- 0.6):(10 +/- 5) by capillary gas chromatography and mass spectrometry. Field trapping experiments demonstrated that the first two compounds are important for the attraction of conspecific males. Z8-14:OAc was found to be attractive when tested separately, while 14:OAc acted as synergist. The attractivity of the three component blend was reduced by 10% admixture of either (E)-10-dodecenyl acetate (E10-12:OAc) or (Z)-10-tetradecenyl acetate (Z10-14:OAc). Field tests of Z10-, Z8- and E10-14:OAc, identified from Ph. acerifoliella females, demonstrated that the first two compounds were essential for the attraction of conspecific males; so both are sex pheromone components. The attractivity of the three component blend of Z10- Z8- and E10-14:OAc was reduced by 10% admixture of (E)-10-dodecenol (E10-12:OH). The following four semiochemical compounds, Z8-14:OAc, Z8-14:OH, E10-14:OAc and 14:OAc, identified from phyllonoryctid females, as well as two sex attraction antagonists for Ph. acerifoliella and Ph. heegerella males, E10-12:OAc and Z10-14:OAc, are new for the family Gracillariidae. The results of field trapping experiments revealed mechanisms ensuring the specificity of the chemocommunication systems in Ph. acerifoliella, Ph. heegerella and Ph. ulmifoliella (Hb.) moths.

  • 104. Mozuraitis, R.
    et al.
    Buda, V.
    Liblikas, I.
    Unelius, C. R.
    Borg-Karlson, Anna-Karin
    KTH, Tidigare Institutioner                               , Kemi.
    Parthenogenesis, calling behavior, and insect-released volatiles of leafminer moth Phyllonorycter emberizaepenella2002Ingår i: Journal of Chemical Ecology, ISSN 0098-0331, E-ISSN 1573-1561, Vol. 28, nr 6, s. 1191-1208Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We proved that the leafminer moth Phyllonorycter emberizaepenella (Lepidoptera: Gracillariidae) reproduces by parthenogenesis of the thelytoky type. Despite a complete absence of males, parthenogenetically reproducing females diurnally demonstrated the calling posture normally used for releasing signaling compounds. Two compounds, which we collected from a calling female, were identified as potential sex pheromone components: (8E,10E)-8,10-tetradecadienyl acetate and (8E,10E)-8,10-tetradecadienol, the latter occurring only in trace amounts. In field experiments, no males were attracted to traps baited with either the potential sex pheromone or with virgin females. Both the pattern of behavior and the chemical characteristics of the pheromone of Ph. emberizaepenella species were similar to those known for Lepidoptera with the usual amphimictic mode of reproduction. Theoretical speculations that in thelytoky, where there is no need to find a sexual partner, the individuals would obtain certain advantages due to reduction in their sexual behavior, were, thus, not confirmed for Ph. emberizaepenella.

  • 105. Mozuraitis, R.
    et al.
    Karalius, V.
    Buda, V.
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Inter- and intraspecific activities of compounds derived from sex pheromone glands of currant borer, Synanthedon tipuliformis (Clerck) (Lepidoptera: Sesiidae)2006Ingår i: Zeitschrift für Naturforschung C - A Journal of Biosciences, ISSN 0939-5075, E-ISSN 1865-7125, Vol. 61, nr 04-mar, s. 278-284Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Gas chromatography and mass spectrometry analyses of crude sex pheromone gland extracts revealed that virgin Synanthedon tipuliformis (Clerck), currant borer (Lepidoptera: Sesiidae) females, produced 6 compounds, structurally related to sex pheromone components of clearwing moths. By comparison of retention times and mass spectra of natural products with corresponding properties of synthetic standards, these compounds were identified as: (2E,13Z)-octadeca-2,13-dien-1-yl acetate (E2,Z13-18:OAc), (3E,13Z)-octadeca-3,13-dien-1-yl acetate (E3,Z13-18:OAc), (13Z)-octadec-13-en-1-yl acetate (M-18:OAc), (2E,13Z)-octadeca-2,13-dien-1-ol (E2,Z13-18:OH), (13Z)-octadec-13-en-1-ol (M-18:OH) and octadecan-1-ol (18:OH) in the ratio 100:07:2.7:3.2:traces. The first 3 compounds were previously known to occur in the sex pheromone gland extracts of currant borers, while the last 3 chemicals are now reported for the first time. Trapping tests carried out in the black currant field revealed that E2,Z13-18:OAc, when tested separately, attracted S. tipuliformis males, while addition of E3,Z13-18:OAc to the main component increased the effectiveness of E2,Z13-18:OAc over seven times. The attractiveness of 6 component lures did not differ significantly from the one of the binary mixture, confirming that E2,Z13-18:OAc and E3,Z13-18:OAc in the ratio1.00:0.7 are essential sex pheromone components of S. tipuliformis. Trapping tests carried out at the dwelling place of Synanthedon scoliaeformis (Borkhausen) (Lepidoptera: Sesiidae) revealed that, in addition to intraspecific synergistic effect, E3,Z13-18:OAc increased the specificity of the pheromone signal of S. tipuliformis, acting by intraspecific mode as an attraction antagonist against S. scoliaeformis males. By this way, it ensured the specificity of the sex attraction signal of the currant borer. Consequently, both compounds E2,Z13-18:OAc and E3,Z13-18:OAc have to be present in pheromone formulations used for monitoring and/or control of S. tipuliformis to avoid effecting non-target species. Other compounds identified from the sex pheromone gland of S. tipuliformis did not show any significant interspecific activity for males of S. scoliaeformis, however, they provide a basis to achieve specificity of a pheromone signal of S. tipuliformis and could act as attraction antagonists against other clearwing moth species which, like S. tipuliformis, employ E2,Z13-18:OAc as their sex pheromone component.

  • 106. Mozuraitis, R.
    et al.
    Kutra, J.
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Buda, V.
    Dynamics of putative sex pheromone components during heat periods in estrus-induced cows2017Ingår i: Journal of Dairy Science, ISSN 0022-0302, E-ISSN 1525-3198, Vol. 100, nr 9, s. 7686-7695Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Determination of the optimal insemination time in dairy cows is vital for fertilization success and is a challenging task due to silent or weak signs of estrus shown by some cows. This can be overcome by combining several estrus detection methods, leading to higher detection rates. However, an efficient, noninvasive method for detecting estrus in cows is still needed. Chemical cues released by the cow during estrus have been proposed to have pheromonal properties and signal readiness to mate to the bull. Such cues could be used in an industrial setting to detect cows in estrus. However, no conclusive published data show temporal changes in putative sex pheromone levels during estrus. The goal of this study was to determine the temporal pattern of putative sex pheromone components during estrus and to assess the reproducibility of changes in pheromone concentration with respect to ovulation time. Two injections of the hormone PGF(2 alpha) were administered over a 2-wk interval to induce and synchronize the estrous cycles of 6 Holstein cows. The precise time of ovulation was determined by means of an ultrasound technique, and estrus was determined by visual observation. Using solid-phase microextraction gas chromatography-mass spectrometry techniques, we showed that acetic and propionic acids, which have been proposed to be putative sex pheromone components in cows, were present in the headspaces of all estrous and diestrous fecal samples, whereas 1-iodoundecane was not detected by solid-phase microextraction or by solvent extraction with diethyl ether. Low levels of acids were observed until 1 d before ovulation, at which point their concentrations increased, peaking around 0.5 d before ovulation. The application of labeled synthetic standards revealed that during the peak of release, 36 +/- 8 ng (average +/- SD) of acetic acid and 10 +/- 3 ng of propionic acid were present in 0.5-g samples of estrous-phase fecal matter compared with 19 +/- 5 and 2.3 +/- 1 ng of acetic and propionic acids, respectively, in the control diestrous samples. After the peak, the amounts of the compounds decreased sharply to match those of the control samples and afterward returned to the baseline readings. This decrease in the amounts of putative pheromone components was registered about 12 h before ovulation, indicating that acetic and propionic acids could be used as biomarkers for the electronic detection of ovulation.

  • 107. Mozuraitis, R.
    et al.
    Stranden, M.
    Ramirez, M. I.
    Borg-Karlson, Anna-Karin
    KTH, Tidigare Institutioner                               , Kemi.
    Mustaparta, H.
    (-)-germacrene D increases attraction and oviposition by the tobacco budworm moth Heliothis virescens2002Ingår i: Chemical Senses, ISSN 0379-864X, E-ISSN 1464-3553, Vol. 27, nr 6, s. 505-509Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The sesquiterpene germacrene D (GD) activates a major type of olfactory receptor neuron on the antennae of the heliothine moths. In Heliothis virescens females, 80% of the recordings have shown activity of one neuron type responding with high sensitivity and selectivity to GD. With the aim of determining the behavioural significance of this sesquiterpene, we have used a two-choice wind-tunnel to study the preference of mated H. virescens females for host plants with and without (-)-GD added. Tobacco plants containing dispensers with low release rate of (-)-GD had a greater attractiveness than tobacco plants without this substance. In addition, a significant increase of oviposition was found on the plants with (-)-GD.

  • 108.
    Mozuraitis, Raimondas
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Buda, Vincas
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Optimization of Solid-Phase Microextraction Sampling for Analysis of Volatile Compounds Emitted from Oestrous Urine of Mares2010Ingår i: Zeitschrift für Naturforschung C - A Journal of Biosciences, ISSN 0939-5075, E-ISSN 1865-7125, Vol. 65, nr 1-2, s. 127-133Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The solid-phase microextraction (SPME) technique was applied and optimized for collection of volatile compounds emitted from oestrous urine of mares Equs cabalus L (Perissodactyla, Equidae) for GC-MS analyses. Variables Such as type Of SPMF fibre, Collection time of volatiles, and addition of salt were optimized to improve the sampling efficiency ill two aspects: extent and selectivity of absorption/adsorption Of urine volatiles onto SPME fibres. The data revealed that the number of volatiles and the total amount represented as quantitative peak areas of the compounds trapped oil fibres coated either with polydimethylsiloxane-divinylbenzene or with divinylbenzene-carboxen-polydimethylsiloxane were significantly higher compared to those coated with polydimethylsiloxane. polyacrylate, and carbowax-divinylbenzene. The polydimethylsiloxane-divinylbenzene-type of the fibre coating was chosen for optimization of sampling time and effect of salt addition. Sampling periods lasted for 15, 30, 60, 120, and 240 min. The optimal collection time of volatiles from urine maintained at about 36 degrees C was 60 min, as the number Of compounds detected with amounts Sufficient for quantification did not differ significantly from those trapped during longer collection periods. No significant increase in total amount of volatiles trapped was registered after 120 min of sampling. Addition Of 0.3 g NaCl to the 2-ml of samples shortened the collection period from 60 to 15 min during which almost all compounds were trapped. Addition of salt has a significant effect at all sampling periods taking into consideration the total amounts Of volatiles trapped. The total intensities increased about 8, 5, 3, 3, and 2 times at collection periods of 15, 30 60, 120, and 240 min, respectively, when compare with the ones obtained from the urine samples with no salt addition. In oestrous mare's urine. 139 +/- 4 (average number standard +/- deviation) volatile compounds Suitable for quantitative analyses were detected compared to 45 compounds collected by the gas-tight syndrome method.

  • 109.
    Mozuraitis, Raimondas
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Buda, Vincas
    Kutra, Jonas
    Borg Karlsson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    p- and m-Cresols emitted from estrous urine are reliable volatile chemical markers of ovulation in mares2012Ingår i: Animal Reproduction Science, ISSN 0378-4320, E-ISSN 1873-2232, Vol. 130, nr 1-2, s. 51-56Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Urine samples from 14 mares, belonging to five breeds, were collected at estrus and diestrus to search for estrous specific volatile compounds which could be used to determine ovulation time. Around 150 volatiles were collected from urine head-space samples by solid phase micro extraction technique, and analyses were conducted by gas chromatography-mass spectrometry methods. Comparison of chromatographic profiles of volatile substances revealed that concentrations of m- and p-cresols were significantly greater during estrus while diethylphthalate was more abundant at diestrus. Monitoring of m- and p-cresols during the period of estrus and a few days before and after estrus revealed irregular changes in amounts of cresols until 3-4 days before ovulation when the concentration of the compounds began to increase with peaks 1 day before ovulation. On the day when ovulation occurred, amounts of the metabolites decreased sharply, almost to basal concentrations, and remained at these concentrations for 6 days - when sampling was finished. In four of the mares changes in the concentration of diethylphthalate were less pronounced and more temporally variable compared with those of cresols. Based on reproducible temporal changes in concentrations of m- and p-cresols, with respect to the time of ovulation, a noninvasive test to determine a precise insemination time could occur. This would save time, reduce costs and simplify the procedure.

  • 110.
    Mozuraitis, Raimondas
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Murtazina, Rushana
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Nylin, Sören
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Nonvolatile Chemical Cues Affect Host-Plant Ranking by Gravid Polygonia c-album Females2012Ingår i: Zeitschrift für Naturforschung C - A Journal of Biosciences, ISSN 0939-5075, E-ISSN 1865-7125, Vol. 67, nr 1-2, s. 93-102Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In a multiple-choice test, the preference of egg-laying Polygonia c-album (comma butterfly) females was studied for oviposition on plants bearing surrogate leaves treated with crude methanol extracts obtained from leaves of seven host-plant species: Humulus lupulus, Urtica dioica, Ulmus glabra, Salix caprea, Ribes nigrum, Corylus avellana, and Betula pubescens. The ranking order of surrogate leaves treated with host-plant extracts corresponded well to that reported on natural foliage, except R. nigrum. Thus, host-plant choice in P c-album seems to be highly dependent on chemical cues. Moreover, after two subsequent fractionations using reversed-phase chromatography the nonvolatile chemical cues residing in the most polar water-soluble fractions evidently provided sufficient information for egg-laying females to discriminate and rank between the samples of more and less preferred plants, since the ranking in these assays was similar to that for natural foliage or whole methanol extracts, while the physical traits of the surrogate leaves remained uniform.

  • 111.
    Mozuraitis, Raimondas
    et al.
    Stockholm Univ, Dept Zool, SE-10691 Stockholm, Sweden.;Nat Res Ctr, Inst Ecol, Lab Chem & Behav Ecol, Akad 2, LT-08412 Vilnius, Lithuania..
    Murtazina, Rushana
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi.
    Zurita, Javier
    Stockholm Univ, Dept Environm Sci & Analyt Chem, SE-10691 Stockholm, Sweden..
    Pei, Yuxin
    Northwest A&F Univ, Dept Appl Chem, Yangling 712100, Shaanxi, Peoples R China..
    Ilag, Leopold
    Stockholm Univ, Dept Environm Sci & Analyt Chem, SE-10691 Stockholm, Sweden..
    Wiklund, Christer
    Stockholm Univ, Dept Zool, SE-10691 Stockholm, Sweden..
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi. Tartu Univ, Div Organ Chem, Inst Technol, EE-50411 Tartu, Estonia..
    Anti-aphrodisiac pheromone, a renewable signal in adult butterflies2019Ingår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, artikel-id 14262Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The male butterfly Pieris napi produces the anti-aphrodisiac pheromone methyl salicylate (MeS) and transfers it to the female during mating. After mating she releases MeS, when courted by conspecific males, which decreases her attractiveness and the duration of male harassment, thus increasing her time available for egg-laying. In previous studies we have shown that males produced MeS from the amino acid L-phenylalanine (L-Phe) acquired during larval stage. In this study we show that adult males of P. napi can utilize L-Phe and aromatic flower volatiles as building blocks for production of anti-aphrodisiac pheromone and transfer it to females during mating. We demonstrate this by feeding butterflies with stable isotope labelled molecules mixed in sugar solutions, and, to mimic the natural conditions, we fed male butterflies with floral nectar of Bunias orientalis plants treated with labelled L-Phe. The volatiles from butterflies and plants were collected and identified by solid phase micro extraction, gas chromatography and mass spectrometry techniques. Since P. napi is polygamous, males would gain from restoring the titre of MeS after mating and the use of aromatic precursors for production of MeS could be considered as an advantageous trait which could enable butterflies to relocate L-Phe for other needs.

  • 112. Mugisha, Maud Kamatenesi
    et al.
    Asiimwe, Savina
    Makerere Univ, Sch Biosci, Kampala, Uganda.
    Namutebi, Agnes
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Kakudidi, Esezah Kyomugisha
    Ethnobotanical study of indigenous knowledge on medicinal and nutritious plants used to manage opportunistic infections associated with HIV/AIDS in western Uganda2014Ingår i: Journal of Ethnopharmacology, ISSN 0378-8741, E-ISSN 1872-7573, Vol. 155, nr 1, s. 194-202Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ethnopharmacological relevance: Traditional medicine plays an important role in the daily lives of the people of Uganda to treat a wide range of health problems. Our study presents results of an ethnobotanical inventory conducted to identify and document medicinal and nutritional plants used in the management of opportunistic infections associated with human immunodeficiency virus / acquired immunodeficiency syndrome (HIV/AIDS), the plant parts used, preparation and administration methods of herbal remedies. Materials and methods: We performed semi-structured interviews with 79 respondents (women 78%, men 22%), who included specialists in medicinal plants (such as traditional birth attendants and herbalists) and non specialists with general knowledge of plant use. Respondents answered a semi-structured questionnaire regarding their knowledge of plants and general treatment practices including management of HIV/AIDS opportunistic infections. The reported plants were collected and identified. Data were analyzed using factor informant consensus and fidelity level to determine homogeneity of informants' knowledge on medicinal and nutritional plants suitable for different ailment categories and the most preferred plant species used to treat each ailment category in the study areas. Results: The study revealed 148 plant species belonging to 54 families, most of which were herbs (50.7%). Leaves (61.6%) were the most frequently used parts in remedy preparations which were mainly administered orally (72%). The majority of plants (62%) were harvested from wild habitats. The most important species according to fidelity values are Hibiscus sabdariffa L for anaemia, Mangifera indica L for cough, Zehneria scabra (L F.) Sond. for skin infections, Rhus natalensis Bernh.ex.Krauss for diarrhoea and Tarenna pavettoides (Harv.) Sim for appetite boosting. The factor informant consensus highlighted the agreement in the use of plants and showed that the respiratory infections category had the greatest agreement (0.60). Family Asteraceae accounted for 15% of the total species recorded. Sixty plant species (40%) of the plants provide nutritional support. Conclusion: The study revealed that folk medicine is still widely practised. Fidelity level values indicate that these plants are the most preferred Species for particular ailments. The high consensus value (0.6) indicated that there was high agreement in the use of plants for respiratory ailments among others. These preferred plant species could be prioritized for conservation and subjected to chemical screening to ascertain their pharmacological activities.

  • 113.
    Murtazina, Rushana
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Mozuraitis, Raimondas
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Liblikas, Ilme
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Amino acid fertilized flowering plants for studying the transfer of pheromone precursors to butterfliesManuskript (preprint) (Övrigt vetenskapligt)
  • 114.
    Murtazina, Rushana
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Mozuraitis, Raimondas
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Pei, Yuxin
    Wiklund, Christer
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Anti-aphrodisiac pheromone production in adult butterfilesManuskript (preprint) (Övrigt vetenskapligt)
  • 115. Noziere, Barbara
    et al.
    Gonzalez, Nelida J. D.
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Pei, Yuxin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Pettersson Redeby, Johan
    KTH, Skolan för kemivetenskap (CHE), Kemi, Analytisk kemi.
    Krejci, Radovan
    Dommen, Josef
    Prevot, Andre S. H.
    Anthonsen, Thorleif
    Atmospheric chemistry in stereo: A new look at secondary organic aerosols from isoprene2011Ingår i: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 38, s. L11807-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Isoprene, a compound emitted by vegetation, could be a major contributor to secondary organic aerosols (SOA) in the atmosphere. The main evidence for this contribution were the 2-methylbutane-1,2,3,4-tetraols, or 2-methyltetrols (2-methylerythritol and 2-methylthreitol) present in ambient aerosols. In this work, the four stereoisomers of these tetraols were analyzed in aerosols from Aspvreten, Sweden. 2-C-methyl-D-erythritol was found in excess over its enantiomer in the Spring/Summer, by up to 29% in July. This clearly indicated some biological origins for this enantiomer, consistent with its well-documented production by plants and other living organisms. In addition, a minimum of 20 to 60% of the mass of racemic tetraols appeared from biological origin. Thus, the SOA mass produced by isoprene in the atmosphere is less than what indicated by the 2-methyltetrols in aerosols. Our results also demonstrate that stereochemical speciation can distinguish primary and secondary organic material in atmospheric aerosols.

  • 116. Ocheng, Francis
    et al.
    Bwanga, Freddie
    Boström, Elisabeth Almer
    Joloba, Moses
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Yucel-Lindberg, Tulay
    Obua, Celestino
    Gustafsson, Anders
    Essential Oils from Ugandan Medicinal Plants: In Vitro Cytotoxicity and Effects on IL-1 beta-Induced Proinflammatory Mediators by Human Gingival Fibroblasts2016Ingår i: Evidence-based Complementary and Alternative Medicine, ISSN 1741-427X, E-ISSN 1741-4288, artikel-id 5357689Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The study investigated cytotoxicity of essential oils from four medicinal plants (Bidens pilosa, Ocimum gratissimum, Cymbopogon nardus, and Zanthoxylum chalybeum) on human gingival fibroblasts and their effects on proinflammatory mediators' secretion. Cytotoxicity of essential oils was investigated using 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay. Effects of essential oils at subcytotoxicity concentrations on interleukin-(IL-) 6, IL-8, and prostaglandin E-2 (PGE(2)) secretions by gingival fibroblasts treated with IL-1 beta (300 pg/mL) were evaluated by ELISA and EIA. IC50 values of the essential oils ranged from 26 mu g/mL to 50 mu g/mL. Baseline and IL-1 beta-induced secretion of PGE(2) was inhibited by treatment with essential oil from O. gratissimum. Essential oils from B. pilosa and C. nardus had synergistic effects with IL-1 beta on PGE(2) seceretion. In conclusion, the study suggests that essential oil from O. gratissimum decreases gingival fibroblasts secretion of PGE(2), while essential oils from B. pilosa and C. nardus increase PGE(2) secretion. Essential oil from Z. chalybeum was the most cytotoxic, while oil from C. nardus was the least cytotoxic. Although the clinical significance of these findings remains to be determined, it may be suggested that essential oil from O. gratissimum, applied at subcytotoxicity concentrations, could reduce the participation of gingival fibroblasts in the gingival inflammation and tissue destruction associated with periodontitis.

  • 117. Ocheng, Francis
    et al.
    Bwanga, Freddie
    Joloba, Moses
    Borg-Karlson, Ann-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Gustafsson, Anders
    Obua, Celestino
    Antibacterial activities of extracts from Ugandan medicinal plants used for oral care2014Ingår i: Journal of Ethnopharmacology, ISSN 0378-8741, E-ISSN 1872-7573, Vol. 155, nr 1, s. 852-855Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ethnopharmacological relevance: Medicinal plants are widely used for treatment of oral/dental diseases in Uganda. Aim of the study: To investigate antibacterial activities of 16 commonly used medicinal plants on microorganisms associated with periodontal diseases (PD) and dental caries (DC). Materials and methods: Pulp juice and solvent extracts (hexane, methanol and water) from the plants were tested against Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia associated with PD and Streptococcus mutans, Streptococcus sobrinus, Lactobacillus acidophilus associated with DC. Tests were done using agar well-diffusion (pulp juice) and agar-dilution (Solvent extracts) assays. Results: Pulp juice from Zanthoxylum chalybeum and Euclea latidens showed activity against all the bacteria, Zanthoxylum chalybeum being most active. Hexane extract from aerial part of Helichrysum odoratissimum was most active (MIC: 0.125-0.5 mg/ml). Methanol extract from leaves of Lantana trifolia showed activity against all bacteria (MIC: 0.25-1 mg/ml). Conclusion: Several of the tested plants showed antibacterial activities against bacteria associated with PD and DC, meriting further investigations.

  • 118. Ocheng, Francis
    et al.
    Bwanga, Freddie
    Joloba, Moses
    Softrata, Abier
    Azeem, Muhammad
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Puetsep, Katrin
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Obua, Celestino
    Gustafsson, Anders
    Essential Oils from Ugandan Aromatic Medicinal Plants: Chemical Composition and Growth Inhibitory Effects on Oral Pathogens2015Ingår i: Evidence-based Complementary and Alternative Medicine, ISSN 1741-427X, E-ISSN 1741-4288, artikel-id 230832Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The study assessed the growth inhibitory effects of essential oils extracted from ten Ugandan medicinal plants (Bidens pilosa, Helichrysum odoratissimum, Vernonia amygdalina, Hoslundia opposita, Ocimum gratissimum, Cymbopogon citratus, Cymbopogon nardus, Teclea nobilis, Zanthoxylum chalybeum, and Lantana trifolia) used traditionally in the management of oral diseases against oral pathogens. Chemical compositions of the oils were explored by GC-MS. Inhibitory effects of the oils were assessed on periodontopathic Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans and cariogenic Streptococcus mutans and Lactobacillus acidophilus using broth dilution methods at concentrations of 1%, 0.1%, and 0.01%. The most sensitive organism was A. actinomycetemcomitans. Its growth was markedly inhibited by six of the oils at all the concentrations tested. Essential oil from C. nardus exhibited the highest activity with complete growth inhibition of A. actinomycetemcomitans and P. gingivalis at all the three concentrations tested, the major constituents in the oil being mainly oxygenated sesquiterpenes. Most of the oils exhibited limited effects on L. acidophilus. We conclude that essential oils from the studied plants show marked growth inhibitory effects on periodontopathic A. actinomycetemcomitans and P. gingivalis, moderate effects on cariogenic S. mutans, and the least effect on L. acidophilus. The present study constitutes a basis for further investigations and development of certain oils into alternative antiplaque agents.

  • 119.
    Ohlsson, Anna B.
    et al.
    KTH, Skolan för bioteknologi (BIO).
    Segerfeldt, Patrik
    KTH, Skolan för bioteknologi (BIO). KTH, Skolan för kemivetenskap (CHE), Kemi.
    Lindström, Anders
    Dalarna University.
    Borg-Karlsson, Anna-Karin M.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Berglund, Torkel
    KTH, Skolan för bioteknologi (BIO).
    UV-B Exposure of Indoor-Grown Picea abies Seedlings Causes an Epigenetic Effect and Selective Emission of Terpenes2013Ingår i: Zeitschrift für Naturforschung C - A Journal of Biosciences, ISSN 0939-5075, E-ISSN 1865-7125, Vol. 68, nr 3-4, s. 139-147Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Terpenoids  are  involved  in  various  defensive  functions  in  plants,  especially  conifers.  Epi-genetic  mechanisms,  for  example  DNA  methylation,  can  infl uence  plant  defence  systems. The purpose of the present study was to investigate the infl uence of UV-B exposure on the release  of  terpenoids  from  spruce  seedlings  and  on  needle  DNA  methylation.  Ten-week-old  seedlings  grown  indoors  were  exposed  to  UV-B  radiation  during  4 h,  and  the  volatile compounds  emitted  from  the  seedlings  were  analysed.  Analysis  of  the  volatiles  1,  3,  and 22 d after this UV-B exposure showed that bornyl acetate, borneol, myrcene, and limonene contents increased during the fi rst 3 days, while at day 22 the level of emission had returned to the control level. UV-B exposure decreased the level of DNA methylation in needles of young  seedlings,  refl ected  in  methylation  changes  in  CCGG  sequences.  Exposure  of  young seedlings  to  UV-B  radiation  might  be  a  way  to  potentiate  the  general  defensive  capacity, improving their ability to survive in outdoor conditions. UV-B-induced defence is discussed in the light of epigenetic mechanisms.

  • 120. Olsson, P. O. C.
    et al.
    Anderbrant, O.
    Lofstedt, C.
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Liblikas, I.
    Electrophysiological and behavioral responses to chocolate volatiles in both sexes of the pyralid moths Ephestia cautella and Plodia interpunctella2005Ingår i: Journal of Chemical Ecology, ISSN 0098-0331, E-ISSN 1573-1561, Vol. 31, nr 12, s. 2947-2961Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Volatiles from chocolate mediate upwind flight behavior in Ephestia cautella and Plodia interpunctella. We used gas chromatography with electroantennographic detection and found 12 active compounds derived from three different chocolate types, i.e., plain, nut-containing, and rum-flavored. Eight of the compounds were identified with mass spectrometry, and the activity of three compounds, ethyl vanillin, nonanal, and phenylacetaldehyde (PAA), was subsequently confirmed in both electrophysiological and behavioral assays. In the electroantennogram experiment, PAA and nonanal were consistently eliciting responses in both species and sexes. Ethyl vanillin was active in males of both species, and also in P. interpunctella females. E. cautella females showed no antennal activity in response to ethyl vanillin. All three volatiles were attractive to E. cautella males and P. interpunctella females in a flight tunnel. E. cautella females were significantly attracted only to ethyl vanillin. P. interpunctella males were attracted to PAA. Ethyl vanillin is a novel insect attractant, whereas both nonanal and phenylacetaldehyde mediate behavior in many insect species. A final experiment revealed that a blend of the three volatiles was required to induce landing in the flight tunnel bioassay, and that the landing rate was dependent on dose. The three-component blend attracted both sexes of P. interpunctella and females of E. cautella, whereas E. cautella males were not attracted.

  • 121. Palsson, Katinka
    et al.
    Jaenson, Thomas G. T.
    Baeckstrom, Peter
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Tick repellent substances in the essential oil of Tanacetum vulgare2008Ingår i: Journal of medical entomology, ISSN 0022-2585, E-ISSN 1938-2928, Vol. 45, nr 1, s. 88-93Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The repellent effect of the essential oils of flower heads of the aromatic plant tansy, Tanacetum vulgare L. (Asteraceae), originating from Sweden, was tested against host-seeking nymphs of the common tick Ixodes ricinus (L.). The essential oils were obtained by steam distillation (SD) and by using an online solvent extraction separation setup. Further fractionations of the SD oils were obtained by medium-pressure liquid chromatography on silica gel. The volatiles of the essential oils and the fractions that exhibited strong tick repellency (90-100%) were collected by solid phase microextraction and identified by gas chromatography-mass spectrometry. The chemical analyses of the oils show that the populations of T. vulgare from Uppsala and Stockholm may represent different chemotypes, but that they exhibited similar tick repellency. Main volatiles detected from oils of T vulgare collected at Uppsala were a-pinene (27%), beta-pinene (11%), pinocamphone (11%), 1,3,3-trimethylcyclohex-l-ene-4-carboxaldehyde (11%), and 1,8-cineole (10%). In the sample collected in Stockholm, the main components were beta-thujone (39%) and camphor (23%) followed by a-thujone (11%) and 1,8-cineole (8%). When constituents in the oils, e.g., alpha-terpineol, 4-terpineol, alpha + beta-thujone, 1,8-cineol, verbenol, and verbenone, were tested separately (each diluted 0.5%, vol:vol), 64-72% tick repellency was obtained.

  • 122.
    Pettersson, Marie
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Single needle analyses by SPME-GC-MS, a miniaturixed method to localize induced stress sites in conifersManuskript (Övrigt vetenskapligt)
  • 123.
    Pettersson, Marie
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Unelius, Rikard
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Semiochemicals related to the aphid Cinara pillicornis (Hartig) and its host, Picea abies. A method to assign diastereomers of nepetalactone2008Ingår i: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1180, nr 1-2, s. 165-170Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Volatiles released by seedlings of Norway spruce infested with the aphid Cinara pilicornis were analyzed using SPME–GC–MS. Among the stress-induced compounds released by the host plant, citronellol, cis–trans-nepetalactone and cis–trans-nepetalactol was found. These compounds originated from the aphids and they were assumed to be pheromone components for this aphid species. To determine the relative stereochemistry of the nepetalactone, a diagnostic method was developed. The method was based on multivariate analysis of tabulated relative intensities of mass fragments of the four nepetalactone diastereomers. In the practical method described, a few pairs of fragments in the mass spectra were compared and, in combination with the Kovat's index, were used to unambiguously identify the relative stereochemistry of the nepetalactone.

  • 124. Rostelien, T.
    et al.
    Borg-Karlson, Anna-Karin
    KTH, Tidigare Institutioner                               , Kemi.
    Faldt, J.
    Jacobsson, U.
    Mustaparta, H.
    The plant sesquiterpene germacrene D specifically activates a major type of antennal receptor neuron of the tobacco budworm moth Heliothis virescens2000Ingår i: Chemical Senses, ISSN 0379-864X, E-ISSN 1464-3553, Vol. 25, nr 2, s. 141-148Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Plants release hundreds of volatiles that are important in interactions with insects or other organisms. However, knowledge is scarce as to which of the compounds are detected by the organism's olfactory receptor neurons. In the present study, single receptor neurons on the antennae of the tobacco budworm moth, Heliothis virescens, were screened far their sensitivities to naturally produced plant volatiles by the use of gas chromatography linked to electrophysiological recordings from single cells (GC-SCR). Plant volatiles, collected by aeration of host and non-host plants, were tested on each receptor neuron via parallel GC-columns. Thus, simultaneous recordings of the gas chromatogram and the neuron responses to each component were obtained. One type of receptor neuron, appearing in 80% of all experiments, responded with high sensitivity and selectivity to one particular component, present in host as well as non-host mixtures. The component, identified as a sesquiterpene hydrocarbon by linked gas chromatography-mass spectrometry, was isolated from a sesquiterpene fraction of cubebe oil and identified by NMR as germacrene D. The purified compound was then re-tested via gas chromatography on the same receptor neuron type, verifying the identification. A weaker response to another sesquiterpene hydrocarbon was also recorded.

  • 125. Rostelien, T.
    et al.
    Borg-Karlson, Anna-Karin
    KTH, Tidigare Institutioner                               , Kemi.
    Mustaparta, H.
    Selective receptor neurone responses to E-beta-ocimene, beta-myrcene, E,E-alpha-farnesene and homo-farnesene in the moth Heliothis virescens, identified by gas chromatography linked to electrophysiology2000Ingår i: Journal of Comparative Physiology A. Sensory, neural, and behavioral physiology, ISSN 0340-7594, E-ISSN 1432-1351, Vol. 186, nr 9, s. 833-847Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An important question in olfaction is for which odorants receptor neurones have evolved. In the present study, olfactory receptor neurones on the antennae of the tobacco budworm moth Heliothis virescens were screened for sensitivity to naturally occurring plant-produced volatiles by the use of gas chromatography linked to electrophysiology. Volatiles of host as well as non-host: plants collected by headspace techniques were used for stimulating the neurones, sequentially via two columns, one polar and one nonpolar installed in parallel in the gas chromatograph. Three types of neurones presented in this paper responded to one, two or three compounds for which the retention times were determined ill both column types. The chemical structures of the active components were determined on the basis of mass spectrometry linked to gas chromatography, indicating E-beta -ocimene and beta -myrcene as stimulants for neurone type 1, E,E,alpha -farnesene for neurone type 2 and homo-farnesene for neurone type 3. Re-testing authentic materials verified the identifications for the type I neurones. The results demonstrate a high specificity for the three types of neurones by strong responses to one or two structurally similar compounds out of hundreds present in a large variety of plants. The study exemplifies plant odour detection by narrowly tuned receptor neurones in a polyphagous moth species.

  • 126. Rostelien, T.
    et al.
    Stranden, M.
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Mustaparta, H.
    Olfactory receptor neurons in two heliothine moth species responding selectively to aliphatic green leaf volatiles, aromatic compounds, monoterpenes and sesquiterpenes of plant origin2005Ingår i: Chemical Senses, ISSN 0379-864X, E-ISSN 1464-3553, Vol. 30, nr 5, s. 443-461Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Moths of the subfamily Heliothinae are suitable models for comparative studies of plant odour information encoded by the olfactory system. Here we identify and functionally classify types of olfactory receptor neurons by means of electrophysiological recordings from single receptor neurons linked to gas chromatography and to mass spectrometry. The molecular receptive ranges of 14 types in the two polyphagous species Heliothis virescens and Helicoverpa armigera are presented. The receptor neurons are characterized by a narrow tuning, showing the best response to one primary odorant and weak responses to a few chemically related compounds. The most frequently occurring of the 14 types constituted the receptor neurons tuned to (+)-linalool, the enantioselectivity of which was shown by testing two samples with opposite enantiomeric ratios. These neurons, also responding to dihydrolinalool, were found to be functionally similar in the two related species. The primary odorants for 10 other receptor neuron types were identified as (3Z)-hexenyl acetate, (+)-3-carene, trans-pinocarveol, trans-verbenol, vinylbenzaldehyde, 2-phenylethanol, methyl benzoate, alpha-caryophyllene and caryophyllene oxide, respectively. Most odorants were present in several host and non-host plant species, often in trace amounts. The specificity as well as the co-localization of particular neuron types so far recorded in both species showed similarities of the olfactory systems receiving plant odour information in these two species of heliothine moths.

  • 127.
    Schubert, Fredrik
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Pålsson, Katinka
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Santangelo, Ellen
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Sulfate turpentine: a resource of tick repellent compounds2017Ingår i: Experimental & applied acarology, ISSN 0168-8162, E-ISSN 1572-9702, Vol. 72, nr 3, s. 291-302Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Compounds with tick (Ixodes ricinus) repellent properties were isolated from sulfate turpentine consisting of Norway spruce (80%) and Scots pine (20%) from southern Sweden. The turpentine was divided into two fractions by distillation under reduced pressure resulting in one monoterpene hydrocarbon fraction and a residual containing higher boiling terpenoids. The monoterpene fraction was further oxidized with SeO2 to obtain oxygenated monoterpenes with potential tick repellent properties. The oxidized fraction and the high boiling distillation residual were each separated by medium pressure liquid chromatography. The fractions were tested for tick repellency and the compounds in those with highest tick repellency were identified by GC-MS. The fractions with highest repellency contained, mainly (-)-borneol, and mixtures of (+)- and (-)-1-terpineol and terpinen-4-ol. The enantiomers of borneol showed similar tick repellent properties.

  • 128. Sjodin, K.
    et al.
    Persson, M.
    Faldt, J.
    Ekberg, I.
    Borg-Karlson, Anna-Karin
    KTH, Tidigare Institutioner                               , Kemi.
    Occurrence and correlations of monoterpene hydrocarbon enantiomers in Pinus sylvestris and Picea abies2000Ingår i: Journal of Chemical Ecology, ISSN 0098-0331, E-ISSN 1573-1561, Vol. 26, nr 7, s. 1701-1720Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The relative amounts and enantiomeric compositions of monoterpene hydrocarbons in branch and trunk xylem, in needles, and in resin from apical buds in 18 Pinus sylvestris trees have been determined and compared with the terpene content in branch xylem and needles of Picea abies. Besides the high amount of (+)-3-carene, an excess of (+)-alpha-pinene has been found in P. sylvestris, whereas in P. abies (-)-alpha-pinene dominates over (+)-alpha-pinene. In P. sylvestris, clear positive correlations were found between (+)-alpha-pinene and (+)-camphene in the four tissues analyzed. Good positive correlations were also observed between (-)-alpha-pinene and (-)-camphene in the two types of xylem, between (+)-alpha-pinene and (+)-beta-pinene in the resin, and between tricyclene and (-)-camphene in resin and needles. In P. abies, positive correlations were found between (+)-alpha-pinene and (+)-camphene in the branch xylem and between tricyclene and (-)-camphene as well as between (-)-alpha-pinene and (-)-camphene in the needles. Complex relationships between (-)-alpha-pinene and (-)-beta-pinene were found both in the P. abies and in the P. sylvestris tissues. The importance of the enantiomeric composition of alpha-pinene for the host selection of Ips typographus, Tomicus piniperda, and Hylobius abietis is discussed.

  • 129. Sofrata, Abier
    et al.
    Santangelo, Ellen M.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Azeem, Muhammad
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Gustafsson, Anders
    Putsep, Katrin
    Benzyl Isothiocyanate, a Major Component from the Roots of Salvadora Persica Is Highly Active against Gram-Negative Bacteria2011Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 6, nr 8, s. e23045-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Plants produce a number of antimicrobial substances and the roots of the shrub Salvadora persica have been demonstrated to possess antimicrobial activity. Sticks from the roots of S. persica, Miswak sticks, have been used for centuries as a traditional method of cleaning teeth. Diverging reports on the chemical nature and antimicrobial repertoire of the chewing sticks from S. persica led us to explore its antibacterial properties against a panel of pathogenic or commensal bacteria and to identify the antibacterial component/s by methodical chemical characterization. S. persica root essential oil was prepared by steam distillation and solid-phase microextraction was used to sample volatiles released from fresh root. The active compound was identified by gas chromatography-mass spectrometry and antibacterial assays. The antibacterial compound was isolated using medium-pressure liquid chromatography. Transmission electron microscopy was used to visualize the effect on bacterial cells. The main antibacterial component of both S. persica root extracts and volatiles was benzyl isothiocyanate. Root extracts as well as commercial synthetic benzyl isothiocyanate exhibited rapid and strong bactericidal effect against oral pathogens involved in periodontal disease as well as against other Gram-negative bacteria, while Gram-positive bacteria mainly displayed growth inhibition or remained unaffected. The short exposure needed to obtain bactericidal effect implies that the chewing sticks and the essential oil may have a specific role in treatment of periodontal disease in reducing Gram-negative periodontal pathogens. Our results indicate the need for further investigation into the mechanism of the specific killing of Gram-negative bacteria by S. persica root stick extracts and its active component benzyl isothiocyanate.

  • 130. Stranden, M.
    et al.
    Borg-Karlson, Anna-Karin
    KTH, Tidigare Institutioner                               , Kemi.
    Mustaparta, H.
    Receptor neuron discrimination of the germacrene D enantiomers in the moth Helicoverpa armigera2002Ingår i: Chemical Senses, ISSN 0379-864X, E-ISSN 1464-3553, Vol. 27, nr 2, s. 143-152Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Plants release complex mixtures of volatiles, including chiral constituents. In the search for the biologically relevant plant odorants, gas chromatography linked to electrophysiological recordings from single receptor neurons has been employed. In heliothine moths, including the females of the Eurasian cotton bollworm moth Helicoverpa armigera, a major type of receptor neurons is identified, showing high sensitivity and selectivity for the sesquiterpene germacrene D. In the present study, gas chromatography with a chiral column linked to single cell recordings were performed. It was found that all germacrene D neurons belonged to one type; all responded to both enantiomers, but (-)-germacrene D had similar to 10 times stronger effect than (+)-germacrene D. Parallel dose-response curves for the two enantiomers were obtained by direct stimulations. The enantiomeric composition of germacrene D, which differed in six plant species and in different individuals of one species, was determined on the basis of the neuron responses. The results, showing the presence of one neuron type for receiving the information about germacrene D in the various plants, suggests that the two enantiomers mediate the same kind of information to the moth, but with different intensity.

  • 131. Stranden, M.
    et al.
    Liblikas, I.
    Konig, W. A.
    Almaas, T. J.
    Borg-Karlson, Anna-Karin
    KTH, Tidigare Institutioner                               , Kemi.
    Mustaparta, H.
    (-)-germacrene D receptor neurones in three species of heliothine moths: structure-activity relationships2003Ingår i: Journal of Comparative Physiology A. Sensory, neural, and behavioral physiology, ISSN 0340-7594, E-ISSN 1432-1351, Vol. 189, nr 7, s. 563-577Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Specificity of olfactory receptor neurones plays an important role in food and host preferences of a species, and may have become conserved or changed in the evolution of polyphagy and oligophagy. We have identified a major type of plant odour receptor neurones responding to the sesquiterpene germacrene D in three species of heliothine moths, the polyphagous Heliothis virescens and Helicoverpa armigera and the oligophagous Helicoverpa assulta. The neurones respond with high sensitivity and selectivity to (-)-germacrene D, as demonstrated by screening via gas chromatography with numerous mixtures of plant volatiles. Germacrene D was present in both host and non-host plants, but only in half of the tested species. The specificity of the neurones was similar in the three species, as shown by the 'secondary' responses to a few other sesquiterpenes. The effect of (-)-germacrene D was about ten times stronger than that of the (+)-enantiomer, which again was about ten times stronger than that of (-)-alpha-ylangene. Weaker effects were obtained for (+)-beta-ylangene, (+)-alpha-copaene, beta-copaene and two unidentified sesquiterpenes. The structure-activity relationship shows that the important properties of (-)-germacrene D in activating the neurones are the ten-membered ring system and the three double bonds acting as electron-rich centres, in addition to the direction of the isopropyl-group responsible for the different effects of the germacrene D enantiomers.

  • 132. Stranden, M.
    et al.
    Rostelien, T.
    Liblikas, I.
    Almaas, T. J.
    Borg-Karlson, Anna-Karin
    KTH, Tidigare Institutioner                               , Kemi.
    Mustaparta, H.
    Receptor neurones in three heliothine moths responding to floral and inducible plant volatiles2003Ingår i: Chemoecology, ISSN 0937-7409, E-ISSN 1423-0445, Vol. 13, nr 3, s. 143-154Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Some plant volatiles are produced in response to herbivory of several insect species, including heliothine larvae. In the present study of female heliothine moths, four co-located receptor neurone types were identified, of which three types responded strongest to the inducible compounds E-beta-ocimene, E,E-alpha-farnesene and E,E-TMTT, respectively. The fourth type responded strongest to geraniol, which is a common floral volatile. The narrow tuning of each receptor neurone type was demonstrated by responses to a few structurally-related monoterpenes, sesquiterpenes, homo-terpenes and monoterpene alcohols, respectively, out of hundreds of plant constituents tested. The four neurone types showed the same relation of spike amplitudes and ranking of effective compounds in the three heliothine species; the polyphagous Heliothis virescens and Helicoverpa armigera and the oligophagous Helicoverpa assulta. The results indicate the presence of functionally similar types of plant odour-receptor neurones in the three related species, and suggest conservation or reappearance of functionally similar olfactory receptors in related species, independent of the evolution of polyphagy and oligophagy.

  • 133. Sunnerheim, Kerstin
    et al.
    Nordqvist, Anneli
    Nordlander, Goran
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Unelius, C. Rickard
    Bohman, Bjorn
    Nordenhem, Henrik
    Hellqvist, Claes
    Karlen, Anders
    Quantitative structure-activity relationships of pine weevil antifeedants, a Multivariate approach2007Ingår i: Journal of Agricultural and Food Chemistry, ISSN 0021-8561, E-ISSN 1520-5118, Vol. 55, nr 23, s. 9365-9372Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Antifeedant activity of mainly phenylpropanoic, cinnamic, and benzoic acids esters was tested on the pine weevil, Hylobius abiefis (L.). Of 105 compounds screened for activity, 9 phenylpropanoates, 3 cinnamates, and 4 benzoates were found to be highly active antifeeclants. To understand the structure-activity relationships of these compounds, a multivariate analysis study was performed. A number of molecular and substituent descriptors were calculated and correlated to results from two-choice feeding tests with H. abietis. Three local models were developed that had good internal predictive ability. External test sets showed moderate predictivity. In general, low polarity, small size, and high lipophilicity were characteristics for compounds having good antifeeclant activity.

  • 134. Ulland, S.
    et al.
    Ian, E.
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Mustaparta, H.
    Discrimination between enantiomers of linalool by olfactory receptor neurons in the cabbage moth Mamestra brassicae (L.)2006Ingår i: Chemical Senses, ISSN 0379-864X, E-ISSN 1464-3553, Vol. 31, nr 4, s. 325-334Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Plants emit complex blends of volatiles, including chiral compounds that might be detected by vertebrates and invertebrates. Insects are ideal model organisms for studying the underlying receptor neuron mechanisms involved in olfactory discrimination of enantiomers. In the present study, we have employed two-column gas chromatography linked to recordings from single olfactory receptor neurons of Mamestra brassicae, in which separation of volatiles in a polar and a chiral column was performed. We here present the response properties of olfactory receptor neurons tuned to linalool. The narrow tuning of these receptor neurons was demonstrated by their strong responses to (R)-(-)-linalool, the weaker responses to the (+)-enantiomer as well as a few structurally related compounds, and no responses to the other numerous plant released volatiles. The enantioselectivity was verified by parallel dose-response curves, that of (R)-(-)-linalool shifted 1 log unit to the left of the (S)-(+)-linalool curve. A complete overlap of the temporal response pattern was found when comparing the responses of the same strength. Analysis of the spike amplitude and waveform indicated that the responses to the two enantiomers originated from the same neuron.

  • 135. Ulland, S.
    et al.
    Ian, E.
    Mozuraitis, Raimondas
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Meadow, R.
    Mustaparta, H.
    Methyl salicylate, identified as primary odorant of a specific receptor neuron type, inhibits oviposition by the moth Mamestra brassicae L. (Lepidoptera, Noctuidae)2008Ingår i: Chemical Senses, ISSN 0379-864X, E-ISSN 1464-3553, Vol. 33, nr 1, s. 35-46Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The cabbage moth, Mamestra brassicae L. (Lepidoptera, Noctuidae), is a polyphagous species that is often choosing plants of Brassica as hosts for oviposition. In the search for biologically relevant odorants used by these moths, gas chromatography linked to electrophysiological recordings from single receptor neurons (RNs) has been employed, resulting in classification of distinct types of neurons. This study presents specific olfactory RNs responding to methyl salicylate (MeS) as primary odorant and showing a weak response to methyl benzoate, the 2 aromatic compounds occurring together in several plant species. In 2 cases, the neuron was colocated with another RN type responding to 6 green leaf volatiles: 1-hexanol, (3Z)-hexen-1-ol, (2E)-hexen-1-ol, (3Z)-hexenyl acetate, (2Z)-hexen-1-ol, and an unidentified compound. Whereas the specific RNs detected the minor amounts of MeS in some plants, the compound was not found by gas chromatography linked to mass spectrometry in intact plants, but it was found after herbivore attack. The behavioral effect of MeS was studied in outdoor test arenas with Brassica napus and artificial plants. These experiments indicated that mated M. brassicae females avoid plants with dispensers emitting MeS. As it is induced by caterpillar feeding, this compound may mediate a message to mated M. brassicae females that the plant is already occupied.

  • 136. Ulland, S.
    et al.
    Ian, E.
    Stranden, M.
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Mustaparta, H.
    Plant volatiles activating specific olfactory receptor neurons of the cabbage moth Mamestra brassicae L. (Lepidoptera, Noctuidae)2008Ingår i: Chemical Senses, ISSN 0379-864X, E-ISSN 1464-3553, Vol. 33, nr 6, s. 509-522Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Herbivore insects are suitable model organisms for studying how plant odor information is encoded in olfactory receptor neurons (RNs). By the use of gas chromatography linked to electrophysiological recordings from single RNs, screening for sensitivity to naturally produced plant odorants is possible in order to determine the molecular receptive ranges of the neurons. Using this method, we have in this study of the cabbage moth, Mamestra brassicae, classified 21 types of olfactory RNs according to their responses to odorants present in the host plants of Brassicae, in the related species of Arabidopsis, as well as in essential oils of nonhost plants like ylang-ylang. Most of the RNs were tuned to one or a few structurally similar compounds, showing minimal overlap of their molecular receptive ranges. Whereas some RNs displayed a novel tuning, others were tuned to the same compounds as neurons in other insect species. We also found colocation in the same sensillum of 3 RN types with the same response characteristics and tuning as 3 colocated types described in heliothine moths living on different host plants. The presence of similar RN types across different insect species implies conservation or reappearance of the RN types, independent of the evolution of host plant ranges.

  • 137. Unelius, C. Rikard
    et al.
    Nordlander, Goran
    Nordenhem, Henrik
    Hellqvist, Claes
    Legrand, Sacha
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Structure-activity relationships of benzoic acid derivatives as antifeedants for the pine weevil, Hylobius abietis2006Ingår i: Journal of Chemical Ecology, ISSN 0098-0331, E-ISSN 1573-1561, Vol. 32, nr 10, s. 2191-2203Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Aromatic organic compounds found in the feces of the pine weevil, Hylobius abietis (L.) (Coleoptera: Curculionidae), have been shown to deter feeding behavior in this species, which is a serious pest of planted conifer seedlings in Europe. We evaluated 55 benzoic acid derivatives and a few homologs as antifeedants for H. abietis. Structure-activity relationships were identified by bioassaying related compounds obtained by rational syntheses of functional group analogs and structural isomers. We identified five main criteria of efficiency as antifeedants among the benzoic acid derivatives. By predicting optimal structures for H. abietis antifeedants, we attempted to find a commercial antifeedant to protect conifer seedlings against damage by H. abietis in regenerating forests. New, highly effective antifeedants are methyl 2,4-dimethoxybenzoate, isopropyl 2,4-dimethoxybenzoate, methyl 2-hydroxy-3-methoxybenzoate, methyl (3,5-dimethoxyphenyl)acetate, and methyl (2,5-dimethoxyphenyl)acetate. Of these, methyl 2,4-dimethoxybenzoate and isopropyl 2,4-dimethoxybenzoate have the highest antifeedant indices of all substances tested and are the best candidates for practical applications in order to protect planted seedlings in the field.

  • 138. Valterova, Irena
    et al.
    Kunze, Jan
    Gumbert, Andreas
    Luxová, Anna
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Liblikas, Ilme
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Kalinova, Blanka
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Male bumble bee pheromonal components in the scent of deceit pollinated orchids; unrecognized pollinator cues?2007Ingår i: Arthropod-Plant Interactions, ISSN 1872-8855, E-ISSN 1872-8847, Vol. 1, nr 3, s. 137-145Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The pollination of the non-rewarding Orchis pauciflora was studied. The most abundant visitors of O. pauciflora were B. terrestris queens. The fragrance of O. pauciflora inflorescence was dominated by a sesquiterpene (E)-beta-farnesene. (E,E)-alpha-Farnesene, (E)-2,3-dihydrofarnesol, geranylcitronellol, and the monoterpenes limonene and 1,8-cineol were found among less abundant constituents. The sesqui- and diterpenes detected in O. pauciflora fragrance are frequent constituents of male marking pheromones of many bumble bee species. Enantioselective analysis of O. pauciflora scent and B. terrestris male marking pheromone revealed the presence of the (S)-isomer of (E)-2,3-dihydrofarnesol in both samples, and electrophysiological experiments showed that mainly the (S)-isomer activated the antennal receptors. In field experiments, O. pauciflora inflorescences were enriched with the main compound (E)-beta-farnesene resulting in significantly increased pollinia export. We here discuss the chemical similarities between orchid and bumble bees and whether the presence of bumble bee male pheromone components in O. pauciflora fragrance increases its fitness.

  • 139. Vongsombath, C.
    et al.
    Pålsson, Katinka
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Björk, L.
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Jaenson, T. G. T.
    Mosquito (Diptera: Culicidae) Repellency Field Tests of Essential Oils From Plants Traditionally Used in Laos2012Ingår i: Journal of medical entomology, ISSN 0022-2585, E-ISSN 1938-2928, Vol. 49, nr 6, s. 1398-1404Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Essential oils of Hyptis suaveolens (Lamiaceae), Croton roxburghii (Euphorbiaceae), and Litsea cubeba (Lauraceae) were tested in the field near Vientiane city, Lao PDR, on humans for repellent activity against mosquitoes. Landing mosquitoes were collected and later identied. The most abundant mosquitoes captured belonged to the genera Armigeres, Culex, and Aedes. All the plant oils tested at concentrations of 1.7 μg/cm 2, 3.3 μg/cm 2, and 6.3 μg/cm 2 were signicantly more mosquito repellent than the negative control. Croton oil was signicantly repellent against mosquitoes of the three genera at the highest (6.3 μg/cm 2) concentration tested. Litsea oil was signicantly repellent against Armigeres at all (1.7 μg/cm 2, 3.3 μg/cm 2, and 6.3 μg/cm 2) concentrations tested. Hyptis oil was signicantly repellent against Armigeres at 3.3μg/cm 2 and 6.3μg/cm 2 and against Culex at 1.7 μg/cm 2 and 6.3 μg/cm 2. The oils were analyzed for chemical content of volatiles, mainly terpenes. Main constituents were α-pinene, sabinene, and 1,8-cineol from oils of the green parts of H. suaveolens; α-pinene, α-pinene, and α-phellandrene from fresh bark of C. roxburghii; and α-pinene, α-phellandrene, sabinene, and 1,8-cineol from fresh fruits of L. cubeba.

  • 140. Wibe, Atle
    et al.
    Borg Karlsson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. Univ Tartu, Inst Technol, Sect Organ Chem, Estonia.
    Cross, Jerry
    Bichao, Helena
    Fountain, Michelle
    Liblikas, Ilme
    Sigsgaard, Lene
    Combining 1,4-dimethoxybenzene, the major flower volatile of wild strawberry Fragaria vesca, with the aggregation pheromone of the strawberry blossom weevil Anthonomus rubi improves attraction2014Ingår i: Crop Protection, ISSN 0261-2194, E-ISSN 1873-6904, Vol. 64, s. 122-128Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aggregation pheromone of strawberry blossom weevil [Anthonomus rubi Herbst (Col.: Curculionidae)1, a 1:4:1 blend of Grandlure I, II and racemic lavadulol, has been available for pest monitoring for several years but shows low attractancy. Attempts to control A. rubi using the pheromone alone were also unsuccessful. This paper reports the finding that addition of the major flower volatile from wild strawberry flowers [Fragaria vesca L. (Rosaceae)], 1,4-dimethoxybenzene (comprising 98% of the volatiles emitted from wild strawberry flowers), to the aggregation pheromone increased trap catches by over two fold compared to the pheromone alone. There was no significant difference between the response of overwintered or summer emerged adults. Field trials in 2007-2008 in central and southern Norway, Denmark and southern England used green funnel traps with white cross vanes for the evaluations. (-)-Germacrene D, previously shown to be emitted by plants in increased amounts in the presence of pheromone producing weevils, did not improve trap catches. Thus, the combined use of the aggregation pheromone and 1,4-dimethoxybenzene is promising for improved monitoring and possibly control of this important pest of strawberry.

  • 141. Wiegerinck, W.
    et al.
    Setkus, A.
    Buda, V.
    Borg-Karlson, Anna Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Mozũraitis, Raimondas
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    De Gee, A.
    BOVINOSE: Pheromone-based sensor system for detecting estrus in dairy cows2011Ingår i: Procedia Comput. Sci., 2011, s. 340-342Konferensbidrag (Refereegranskat)
    Abstract [en]

    The BOVINOSE project (www.bovinose.eu) aims to develop an electronic nose to detect estrus in a dairy cow, and thus to determine the optimal timing of artificial insemination. The physical principle is based on detection of sex pheromones that are secreted by the cow, exclusively during estrus. These pheromones are the natural olfactory signal for the bull that the cow is in heat. This technology aims to help the dairy farmers in the EU, the vast majority being micro-enterprises run as family businesses.

  • 142.
    Zhao, Tao
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Axelsson, Karolin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Krokene, P.
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Fungal Symbionts of the Spruce Bark Beetle Synthesize the Beetle Aggregation Pheromone 2-Methyl-3-buten-2-ol2015Ingår i: Journal of Chemical Ecology, ISSN 0098-0331, E-ISSN 1573-1561Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Tree-killing bark beetles depend on aggregation pheromones to mass-attack their host trees and overwhelm their resistance. The beetles are always associated with phytopathogenic ophiostomatoid fungi that probably assist in breaking down tree resistance, but little is known about if or how much these fungal symbionts contribute to the beetles’ aggregation behavior. In this study, we determined the ability of four major fungal symbionts of the spruce bark beetle Ips typographus to produce beetle aggregation pheromones. The fungi were incubated on Norway spruce Picea abies bark, malt agar, or malt agar amended with 0.5 % 13C glucose. Volatiles present in the headspace of each fungus were analyzed for 7 days after incubation using a SPME autosampler coupled to a GC/MS. Two Grosmannia species (G. penicillata and G. europhioides) produced large amounts of 2-methyl-3-buten-2-ol (MB), the major component in the beetles’ aggregation pheromone blend, when growing on spruce bark or malt agar. Grosmannia europhioides also incorporated 13C glucose into MB, demonstrating that the fungi can synthesize MB de novo using glucose as a carbon source. This is the first clear evidence that fungal symbionts of bark beetles can produce components in the aggregation pheromone blend of their beetle vectors. This provides new insight into the possible ecological roles of fungal symbionts in bark beetle systems and may deepen our understanding of species interactions and coevolution in these important biological systems.

  • 143.
    Zhao, Tao
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Eerbilgin, Nadir
    Krokene, Paal
    Host resistance elicited by methyl jasmonate reduces emission of aggregation pheromones by the spruce bark beetle: Ips typographus2011Ingår i: Oecologia, ISSN 0029-8549, E-ISSN 1432-1939, Vol. 167, nr 3, s. 691-699Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We treated Norway spruce (Picea abies) stems with methyl jasmonate (MeJA) to determine possible quantitative and qualitative effects of induced tree defenses on pheromone emission by the spruce bark beetle Ips typographus. We measured the amounts of 2-methyl-3-buten-2-ol and (S)-cis-verbenol, the two main components of the beetle's aggregation pheromone, released from beetle entrance holes, along with phloem terpene content and beetle performance in MeJA-treated and untreated Norway spruce logs. As expected, phloem terpene levels were higher and beetle tunnel length was shorter (an indication of poor performance) in MeJA-treated logs relative to untreated logs. Parallel to the higher phloem terpene content and poorer beetle performance, beetles in MeJA-treated logs released significantly less 2-methyl-3-buten-2-ol and (S)-cis-verbenol, and the ratio between the two pheromone components was significantly altered. These results suggest that host resistance elicited by MeJA application reduces pheromone emission by I. typographus and alters the critical ratio between the two main pheromone components needed to elicit aggregation. The results also provide a mechanistic explanation for the reduced performance and attractivity observed in earlier studies when bark beetles colonize trees with elicited host defenses, and extend our understanding of the ecological functions of conifer resistance against bark beetles.

  • 144.
    Zhao, Tao
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi.
    Ganji, Suresh
    Schiebe, Christian
    Bohman, Bjorn
    Weinstein, Philip
    Krokene, Paal
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi.
    Unelius, C. Rikard
    Convergent evolution of semiochemicals across Kingdoms: bark beetles and their fungal symbionts2019Ingår i: The ISME Journal, ISSN 1751-7362, E-ISSN 1751-7370, Vol. 13, nr 6, s. 1535-1545Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Convergent evolution of semiochemical use in organisms from different Kingdoms is a rarely described phenomenon. Tree-killing bark beetles vector numerous symbiotic blue-stain fungi that help the beetles colonize healthy trees. Here we show for the first time that some of these fungi are able to biosynthesize bicyclic ketals that are pheromones and other semiochemicals of bark beetles. Volatile emissions of five common bark beetle symbionts were investigated by gas chromatography-mass spectrometry. When grown on fresh Norway spruce bark the fungi emitted three well-known bark beetle aggregation pheromones and semiochemicals (exo-brevicomin, endo-brevicomin and trans-conophthorin) and two structurally related semiochemical candidates (exo-1,3-dimethyl-2,9-dioxabicyclo[3.3.1]nonane and endo-1,3-dimethyl-2,9-dioxabicyclo[3.3.1]nonane) that elicited electroantennogram responses in the spruce bark beetle Ips typographus. When grown on malt agar with C-13 D-Glucose, the fungus Grosmannia europhioides incorporated C-13 into exo-brevicomin and trans-conophthorin. The enantiomeric compositions of the fungus-produced ketals closely matched those previously reported from bark beetles. The production of structurally complex bark beetle pheromones by symbiotic fungi indicates cross-kingdom convergent evolution of signal use in this system. This signaling is susceptible to disruption, providing potential new targets for pest control in conifer forests and plantations.

  • 145.
    Zhao, Tao
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Krokene, Paal
    Björklund, Niklas
    Långström, Bo
    Solheim, Halvor
    Christiansen, Erik
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    The influence of Ceratocystis polonica inoculation and methyl jasmonate application on terpene chemistry of Norway spruce, Picea abies2010Ingår i: Phytochemistry, ISSN 0031-9422, E-ISSN 1873-3700, Vol. 71, nr 11-12, s. 1332-1341Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Constitutive and inducible terpene production is involved in conifer resistance against bark beetles and their associated fungi. In this study 72 Norway spruce (Picea abies) were randomly assigned to methyl jasmonate (MJ) application, inoculation with the bluestain fungus Ceratocystis polonica, or no-treatment control. We investigated terpene levels in the stem bark of the trees before treatment, 30 days and one year after treatment using GC-MS and two-dimensional GC (2D-GC) with a chiral column, and monitored landing and attack rates of the spruce bark beetle, Ips typographus, on the trees by sticky traps and visual inspection. Thirty days after fungal inoculation the absolute amount and relative proportion of (+)-3-carene, sabinene, and terpinolene increased and (+)-alpha-pinene decreased. Spraying the stems with MJ tended to generally increase the concentration of most major terpenes with minor alteration to their relative proportions, but significant increases were only observed for (-)-beta-pinene and (-)-limonene. Fungal inoculation significantly increased the enantiomeric ratio of (-)-alpha-pinene and (-)-limonene 1 month after treatment, whereas MJ only increased that of (-)-limonene. One year after treatment, both MJ and fungal inoculation increased the concentration of most terpenes relative to undisturbed control trees, with significant changes in (-)-beta-pinene, (-)-beta-phellandrene and some other compounds. Terpene levels did not change in untreated stem sections after treatment, and chemical induction by MJ and C polonica thus seemed to be restricted to the treated stem section. The enantiomeric ratio of (-)-alpha-pinene was significantly higher and the relative proportions of ( -)-limonene were significantly lower in trees that were attractive to bark beetles compared to unattractive trees. One month after fungal inoculation, the total amount of diterpenes was significantly higher in putative resistant trees with shorter lesion lengths than in putative susceptible trees with longer lesions. Thus, terpene composition in the stem bark may be related to resistance of Norway spruce against I. typographus and C. polonica.

  • 146.
    Zhao, Tao
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Krokene, Paal
    Hu, Jiang
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Christiansen, Erik
    Björklund, Niklas
    Långström, Bo
    Solheim, Halvor
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Induced Terpene Accumulation in Norway Spruce Inhibits Bark Beetle Colonization in a Dose-Dependent Manner2011Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 6, nr 10, s. e26649-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Tree-killing bark beetles (Coleoptera, Scolytinae) are among the most economically and ecologically important forest pests in the northern hemisphere. Induction of terpenoid-based oleoresin has long been considered important in conifer defense against bark beetles, but it has been difficult to demonstrate a direct correlation between terpene levels and resistance to bark beetle colonization. Methods: To test for inhibitory effects of induced terpenes on colonization by the spruce bark beetle Ips typographus (L.) we inoculated 20 mature Norway spruce Picea abies (L.) Karsten trees with a virulent fungus associated with the beetle, Ceratocystis polonica (Siem.) C. Moreau, and investigated induced terpene levels and beetle colonization in the bark. Results: Fungal inoculation induced very strong and highly variable terpene accumulation 35 days after inoculation. Trees with high induced terpene levels (n = 7) had only 4.9% as many beetle attacks (5.1 vs. 103.5 attacks m(-2)) and 2.6% as much gallery length (0.029 m m(-2) vs. 1.11 m m(-2)) as trees with low terpene levels (n = 6). There was a highly significant rank correlation between terpene levels at day 35 and beetle colonization in individual trees. The relationship between induced terpene levels and beetle colonization was not linear but thresholded: above a low threshold concentration of similar to 100 mg terpene g(-1) dry phloem trees suffered only moderate beetle colonization, and above a high threshold of similar to 200 mg terpene g(-1) dry phloem trees were virtually unattacked. Conclusion/Significance: This is the first study demonstrating a dose-dependent relationship between induced terpenes and tree resistance to bark beetle colonization under field conditions, indicating that terpene induction may be instrumental in tree resistance. This knowledge could be useful for developing management strategies that decrease the impact of tree-killing bark beetles.

  • 147.
    Zhao, Tao
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Solheim, Halvor
    Långström, Bo
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Storm-induced tree resistance and chemical differences in Norway spruce (Picea abies)2011Ingår i: Annals of Forest Science, ISSN 1286-4560, E-ISSN 1297-966X, Vol. 68, nr 3, s. 657-665Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Windstorm is one of the most destructive environmental disturbance factors on forests, but its influence on conifer defense chemistry and susceptibility to insects and diseases is not well understood.

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