98 research outputs found
Evaluation of Polar and Non-Polar Fractions of Essential Oil from Cymbopogon Citratus (DC.) Stapf
The essential oil of Cymbopogon citratus collected from Bangalore was fractionated into non-polar and polar fractions using silica column chromatography. The essential oil and the fractions were analyzed by GC and GC-MS. The main constituents of the essential oil were citral [neral (30.4%) + geranial (41.8%)], ß- myrcene (8.8%) and geraniol (2.2%) along with traces of sesquiterpenes, aliphatic compounds and phenylpropanoids. GC analysis of the non-polar chromatographic fraction along with the ß-myrcene standard showed that the non-polar fraction is rich in ß-myrcene (=93.87%) and the polar fraction contained the oxygenated terpenes viz., citral (neral+geranial), geraniol, linalool, isocitral as major constituents
Herbivore-induced indirect defense of Arabidopsis : ecogenomic approach to the role of infochemicals in parasitoid attraction
Plants defend themselves against herbivorous insects with the induced production of volatiles that attract the enemies of the herbivores. In this thesis I used an ecogenomic approach to study the role of signal-transduction pathways that regulate the induction of herbivore-induced plant volatiles (HIPV) and the effects of HIPVs on parasitoid host-finding behavior. To this end, I have combined transcriptomics, metabolite analyses and insect behavioral analyses. Nine Arabidopsis thaliana accessions were screened for the emission of HIPVs. The accessions varied in the emission rate of Pieris rapae–induced volatiles after folivory or treatment with the herbivory-mimicking plant hormone jasmonic acid (JA). The relevance of this observed variation in the emission of JA-induced volatiles for host location was tested with Diadegma semiclausum parasitoids. Furthermore, the accessions also varied in transcript levels of genes that are (putatively) involved in the production of some of the recorded HIPV-compounds. The oxylipin JA is the key plant hormone involved in the induction of the HIPV-blend emitted in response to caterpillar folivory. Mutant plants affected in the oxylipin signal-transduction pathway were studied to assess the effects of JA and its oxylipin intermediates 12-oxo-phytodienoate (OPDA) and dinor-OPDA (dnOPDA) on HIPV emission and attraction of the parasitoid D. semiclausum. In contrast to the effect of JA on the induced production of HIPVs, dnOPDA and OPDA were found to have no and little effect, respectively. The HIPV-compound methyl salicylate was shown to be JA-regulated and its abundance in the headspace varied among accessions. The contribution of methyl salicylate to parasitoid attraction was investigated. Bioassays with P. rapae-infested transgenic plants, lacking MeSA production, showed that MeSA negatively influenced D. semiclausum host-finding behavior. Mutant plants were also studied to assess whether JA and its intermediates affected the induction of genes potentially involved in defense. The different oxylipins were shown to have distinct roles in induced defense signaling. Jasmonic acid had the strongest effect on transcript levels of defense-related genes from the oxylipin- and shikimate signal-transduction pathway. Minor roles were observed for OPDA and dnOPDA in the induction of one of these genes. Utilizing an ecogenomic approach has provided new insight into the mechanisms underlying insect-plant interactions and holds promising opportunities. <br/
Characterisation of different hop ecotypes (Humulus lupulus, L.) in Central Italy and evaluation of the biological activity of their extracts, EO and components against Sitophilus granarius (L.)
Hepatoprotective effect of Foeniculum vulgare essential oil: A carbon-tetrachloride induced liver fibrosis model in rats
Hepatoprotective activity of Foeniculum vulgare (fennel) essential oil was studied using a carbon tetrachloride- induced liver fibrosis model in rats. The hepatotoxicity produced by chronic carbon tetrachloride administration was found to be inhibited by Foeniculum vulgare essential oil with evidence of decreased levels of serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and bilirubin. Histopathological findings also suggest that Foeniculum vulgare essential oil prevents the development of chronic liver damage. The changes in body weights in the rats assigned to the study groups supported these biochemical and histopathological findings. The results of this study clearly indicate that Foeniculum vulgare essential oil has a potent hepatoprotective action against carbon tetrachloride-induced liver fibrosis in rats.
Biology of leaf gall-inducing Thlibothrips manipurenis Muraleedharan, 1982 on Ardisia sp. (Myrsinaceae) in north-eastern India (Thysanoptera: Tubulifera: Phlaeothripidae).
Die Biologie der Rollgallen induzierenden Thlibothrips manipurensis wurde auf Ardisia sp. unter Laborbedingungen untersucht. T. manipurensis legt linear Eier entlang der Ränder der jungen Blätter von Ardisia sp. Die Eier schlüpften in 6,8 d und das Larvalstadium dauerte 3,4 und 8,2 d für Larven I und II. Das Vorpuppenstadium bis zur Vollendung der Verpuppung betrug für T. manipurensis 20,2 Stunden. Nach 4 d begann das Erwachsenenstadium. Jedes Weibchen legte 34±7 Eier und die durchschnittliche Lebensdauer der Erwachsenen (adulten Tiere) betrug 10,2 d. Die Anzahl der Thripse korreliert mit dem Alter der Gallen: 15 Thripse/Galle ist bei jungen (4–10 d) Gallen gefunden, während es 28 in reifen (20 d) Gallen und 36 in alten (25 d) Gallen waren. Das Männchen/Weibchen-Verhältnis in alten Gallen war 1:5. Reife Gallen enthalten eine homogene Gewebestruktur, die aus 12–15 Schichten der Parenchym Zellen besteht, wobei es keinen Unterschied gibt zwischen Schwamm- und Palisaden-Zellen. Die Mesophyll-Zellen in den Gallen grenzen an die obere und untere Epidermis und entwickeln sich im Wesentlichen durch anticlinale Teilung der primordialen Zellen, während diejenigen in der mittleren Region sich durch periclinale Teilung entwickeln. Die letztere erleichtert das Einrollen. In der mitteleren Region waren die Zellen der Gallen-Lamina größer als diejenigen der angrenzenden Epidermis. Der Großteil der Zellen in der Mitte der Gallen-Lamina enthielt in Safranin–Lichtgrün-Färbung dunkel erscheinende Einschlüsse, die mit hoher Wahrscheinlichkeit phenolische Materialien waren. Thliobothrips ist ein Verwandter von Gynaikothrips. Thlibothrips und Gynaikothrips sind die am besten bekannten Gallen induzierenden Taxa. In Südindien sind die Roll-Gallen von Thlibothrips manipurensis in Ardisia sp. (Myrsinaceae, Asteriden, Eudikotyledonen) denen sehr ähnlich, die durch Gynaikothrips flaviantennatus in Blättern der Casearia ellipitca (Salicaceae: Samydeae, Rosiden, Eudikotyledonen) induziert werden. Die Rosiden, Eudikotyledonen sind phylogenetisch ähnlich. Die möglichen Wege von Gynaikothrips und Thlibothrips, verschiedene aber verwandte Pflanzentaxa zu befallen, sind bemerkenswert.Stichwörter
Ardisia sp., galls, marginal-leaf rolls, Myrsinaceae, Phlaeothripidae, population patterns through development, Thlibothrips manipurensis, Thysanoptera, Tubulifera.Biology of the epiphyllous roll-gall-inducing Thlibothrips manipurensis was studied on Ardisia sp. under laboratory conditions. T. manipurensis laid eggs linearly along the margins of tender leaves. Eggs hatched in 6.8 d and the larval duration was 3.4 and 8.2 d for larvae I and II, respectively. After 20.2 h as prepupa, T. manipurensis grew into pupa; adult emergence occurred in 4 d. Each female laid 34±7 eggs and the mean longevity of the adult was 10.2 d. Increase in thrips numbers correlated with the age of the gall: 15 individuals/gall occurred in young (4–10 d) galls, whereas 28 occurred in mature (20 d) galls, and 36 in old (25 d) galls. Male–female ratio in old galls was 1:5. Mature galls included a homogeneous tissue structure, made of 12–15 layers of parenchyma cells with no distinction into spongy and palisade cells. The gall-mesophyll cells adjacent to the upper and lower epidermises developed essentially through anticlinal divisions of the primordial cells, whereas those in mid regions developed through periclinal divisions; the latter facilitates the blade to roll inwards. Cells in the mid region of the galled lamina were larger than those occurring adjacent to the epidermises. Bulk of the cells in the mid-region of the galled lamina included darkly staining inclusions, which, in high likelihood, were phenolic materials. Thliobothrips is an ally of Gynaikothrips. Thlibothrips and Gynaikothrips are the better known gall-inducing taxa. The roll galls induced by Thlibothrips manipurensis on Ardisia sp. (Myrsinaceae, Asterids, Eudicots) are highly similar to those induced by Gynaikothrips flaviantennatus on the leaves of Casearia elliptica (Salicaceae: Samydeae, Rosids, Eudicots) in southern India. Because the Rosids and Asterids are considered related phylogenetically, the possible pathways taken by species of Gynaikothrips and Thlibothrips to radiate exploring different, but related plant taxa appear striking.Keywords
Ardisia sp., galls, marginal-leaf rolls, Myrsinaceae, Phlaeothripidae, population patterns through development, Thlibothrips manipurensis, Thysanoptera, Tubulifera
Volatiles and acceptability of liqueurs from kumquat and grapefruit
The aim of this work was to produce liqueurs from "minor" citrus fruits, such as kumquat and grapefruit, characterize their volatile fraction and evaluate their acceptability by a consumer test. A limoncello sample (LP) was produced under the same conditions and used for comparison. All the new liqueurs were found to be richer in limonene and poorer in oxygenated compounds than the LP. The volatile fraction was mostly represented (85%) by limonene in grapefruit liqueur. Liqueur from kumquat peel (KP) was the richest in volatile compounds, whereas the one from kumquat whole fruit (KWF) was the poorest. This latter also had the particular feature to be the richest in sesquiterpene alcohols. Octanal and decanal, and two acetals deriving from these aldehydes (1,1-diethoxyoctane and 1,1-diethoxydecane) were most prevalent in KP and LP. The consumer test showed that all liqueurs were judged to be acceptable. Nevertheless, limoncello remained the most preferred, while the KWF liqueur obtained the best flavour score in the group of minor citrus fruits
Rapid Commun Mass Spectrom
Rationale:Over 2,800 e-cigarette, or vaping, product use-associated lung injury (EVALI) cases have been reported to the Centers for Disease Control and Prevention (CDC) during August 2019-February 2020. Bronchoalveolar lavage (BAL) fluid samples from 51 EVALI and 99 non-EVALI cases were analyzed for toxicants including terpenes. We describe a novel method to measure selected terpenes in BAL fluid by gas chromatography-tandem mass spectrometry (GC/MS/MS).Methods:\u3b1-Pinene,
f-pinene,
f-myrcene, 3-carene, and limonene were measured in BAL fluid specimens by headspace solid-phase microextraction/gas chromatography/tandem mass spectrometry. We created and characterized BAL fluid pools from non-EVALI individuals to determine assay accuracy, precision, linearity, limits of detection, and analytical specificity. All measurements were conducted in accordance with the CDC\u2019s Division of Laboratory Sciences rigorous method validation procedures.Results:Matrix validation experiments showed that calibration curves in BAL fluid and saline had similar slopes, with differences less than 7%. Assay precision ranged from 2.52% - 5.30%. In addition, the limits of detection for the five analytes ranged from 1.80 \u2013 16.8 ng/L, and their linearity was confirmed with R2 values >0.99.Conclusions:We developed and validated a method to quantify selected terpenes in BAL fluid specimens using GC/MS/MS. The assay provided accurate and precise analyses of EVALI and non-EVALI BAL fluid specimens in support of CDC\u2019s EVALI response. This method is applicable to the determination of a broad range of terpenes in BAL fluid specimens.CC999999/ImCDC/Intramural CDC HHS/United States2021-10-15T00:00:00Z32632930PMC77190588772vault:3625
The secret of dry hopped beers – review
Dry hopped beers gain their characteristic flavour from hop products purposely added during the cold stage of production. Although the production of these beers has not so broad a tradition in the Czech Republic as for instant in Great Britain or the United States, their popularity increases every year. This study provides a complete set of theoretical and practical information about the production of dry hopped beers. The relevant sensory active compounds of hops creating the characteristic beer aroma and factors influencing their transfer into beer are introduced. The last part of the study deals with some important risk factors which must be considered during the production of dry hopped beers
Factors associated with postharvest ripening heterogeneity of "Hass" avocados (Persea americana Mill)
Indexación: Web of ScienceIntroduction. 'Hass' is the main avocado cultivar commercialized worldwide. The extended flowering period, very low percentage of fruit set and inability to ripen on the tree renders the fruit heterogeneous and unpredictable during postharvest management. The "triggered" and "ready-to-eat" growing markets for 'Hass' avocados are affected by the variable postharvest ripening or ripening heterogeneity which creates severe logistical problems for marketers and inconsistent quality delivery to consumers. Synthesis. The dry matter content, the current avocado harvest index that correlates very well with oil content, has been extensively used to harvest 'Hass' avocados to comply with the minimum standards to guarantee consumer satisfaction. However, previous work and empirical experience demonstrate that dry matter does not correlate on a fruit-to-fruit basis with time to reach edible ripeness. Thus, avocados of very different ages are harvested from individual trees, resulting in heterogeneous postharvest ripening of fruit within a specific batch. Several preharvest factors related to environmental and growing conditions and crop management as well as postharvest technology strategies influence the observed variability of postharvest ripening. Conclusion. Modern approaches based on studying the composition of individual fruits displaying contrasting postharvest ripening behavior, combined with non-destructive phenotyping techniques, seem to offer practical solutions for the fresh supply chain of avocados to sort fruit based on their ripening capacity.http://www.pubhort.org/fruits/2016/5/fruits160045.ht
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