The repellence of Aristolochia aff. orbicularis roots against the corn borer Sitophilus zeamais.

The repellence of Aristolochia aff. orbicularis root, a native of Xochipala, Guerrero, Mexico, to the corn borer Sitophilus zeamais (Coleoptera) was investigated. The essential oil was isolated from the aromatic root and its repellent effect was assessed. About 40 components of the oil were identified using gas chromatography-mass spectrometry and other spectroscopic methods. The repellence of the roots, the oil and the chromatography fractions were also evaluated. Some fractions had a higher repellence than the total oil.

Chemical profiles, division of labor and social status in Pachycondyla queens (Hymenoptera: formicidae).

Queens of the neotropical ponerine ant Pachycondyla cf. 'inversa' may co-operate during colony founding. One of several co-founding queens specializes in foraging, whereas the others remain in the nest and guard the brood. Division of labor is achieved by aggressive interactions, which result in the formation of dominance hierarchies. Gas chromatography and mass spectrometry of cuticular hydrocarbons obtained from live queens by SPME revealed consistent differences between the patterns of cuticular hydrocarbons of queens with high versus low rank: only high-ranking queens showed considerable amounts of cuticular pentadecane (n-C15) and heptadecene (n-C17:1). These two substances presumably originate from the queens' Dufour glands.

A trail pheromone component of the ant Mayriella overbecki Viehmeyer (Formicidae: Myrmicinae).

The myrmicine ant Mayriella overbecki lays recruitment trails during foraging and nest emigrations. The trail pheromone originates from the poison gland. From ten identified components of the poison gland secretions only methyl 6-methylsalicylate 1 elicited trail following behavior.

2,3-dimethyl-5-(2-methylpropyl)pyrazine, a trail pheromone component of Eutetramorium mocquerysi Emery (1899) (Hymenoptera: Formicidae).

The ant Eutetramorium mocquerysi (Myrmicinae) is endemic to the island of Madagascar. During foraging and nest emigration the ants lay recruitment trails with secretions from the poison gland. We identified three pyrazine compounds in the poison gland secretion: 2,3-dimethyl-5-(2-methylpropyl)pyrazine 1, 2,3-dimethyl-5-(3-methylbutyl)pyrazine 3, 2,3-dimethyl-5-(2-methylbutyl)pyrazine 4. Only the first component elicited trail-following behavior in the ants. We were unable to investigate whether the other pyrazine components have a synergistic function.

Sulphur-containing "perfumes" attract flower-visiting bats.

We tested the attractiveness of individual scent compounds of bat-pollinated flowers to their pollinators, small flower-visiting bats of the genus Glossophaga (Phyllostomidae). Twenty compounds belonging to four different chemical substance classes were tested, both in the laboratory and in the field. In the laboratory, the bats (Glossophaga soricina) approached odour sources spontaneously and without preceding experience. Without ever receiving any reward they preferred the scent of a sulphur-containing compound, dimethyl disulphide, to several other odour components emitted by bat-pollinated flowers, and to scentless controls. In the field, at La Selva station in the tropical lowland rain forest of Costa Rica, G. commissarisi were attracted by two sulphur-containing compounds, dimethyl disulphide and 2,4-dithiapentane, to visit artificial flowers filled with sugar water. Thus, in nectarivorous bats the sense of smell obviously plays an important role in searching for and localising food sources, and even single components of the scent bouquets of bat-pollinated flowers are attractive. The preference for sulphur-containing odours seems to be innate.

The major histocompatibility complex and the chemosensory signalling of individuality in humans.

The chemosensory identity of mice and rats is determined partly by polymorphic genes of the major histocompatibility complex (MHC). In inbred strains of mice, as well as in seminatural populations, MHC-associated mating preferences selectively influence reproductive success, thus serving to promote heterozygocity in the MHC. In order to determine whether MHC-associated chemosignals are present in humans, two studies were conducted. In a first study, olfactory identification of MHC-associated chemosignals was conducted on 12 trained rats' responses to the urine odors of humans. In a second study, MHC-associated olfactory cues in humans were analyzed by means of gas chromatography. The results indicate that the urine odors of humans are associated with the MHC and demonstrate that the profile of volatile components in the urine odors shows some association with the MHC. Furthermore, results show that a profile of some specific components, as well as a few ubiquitous volatiles, constitutes MHC-associated odor signals in humans.

Fractionation and bioassay of human odor types.

Human urine samples were fractionated to examine the contribution of volatiles to the individual body odor. The samples were obtained from 4 male donors and fractionated using a vacuum technique. The volatiles from the chemical fractions were analyzed using the CLSA technique and gas chromatography. Thereafter, these fractions were tested in a computer-controlled olfactometer by trained rats. Although the rats were able to discriminate the distillation residue, they could not recognize the urine odor in the distilled fraction. The results of gas chromatography indicate a continuous release of volatile constituents in the distillation residue.

The volatile constituents of Elsholtzia flava.

The volatile constituents of the essential oil from Elsholtzia flava Benth. growing in higher elevations of Kumaon region (India) were characterized by combination of GC, GC-MS, GC-FT-IR and NMR. Twenty-two components were identified comprising 93% of the oil. Rose furan (45.0%) and estragol (40.5%) were the major constituents.

Headspace analysis of volatile flower scent constituents of bat-pollinated plants.

The flower scents of 11 bat-pollinated plant species have been investigated using the 'closed-loop-stripping'-adsorption technique. GC and GC/MS analyses of the headspace samples resulted in the identification of 49 compounds, comprising amongst others sulphur compounds, terpenoids and aliphatic compounds.

GC profiles of volatile constituents from human urine obtained by closed loop stripping, purge and trap technique and simultaneous stem distillation-extraction.

Different techniques like "closed loop stripping" [CLSA], "purge and trap" [PTI], and continuous steam distillation extraction [SDE] were used to establish GC profiles of major histocompatibility complex-associated volatile constituents of human urine and statistically evaluated for reliability. Of the three methods investigated, PTI appeared to be superior for the detection of very volatile substances, whereas SDE was the most efficient one with respect to yield. A number of short to medium-chain ketones, 4-hydroxy-3-methoxy-styrene, menthol and nicotine were identified in preliminary analyses.

Ab initio calculations on (Z)-5-decenyl acetate, a component of the pheromone complex of Agrotis segetum (Lepidoptera: Noctuidae) and electrophysiological studies with chain elongated analogues.

Conformational analyses of (Z)-5-decenylacetate, a sex pheromone component of the turnip moth, Agrotis segetum, and double unsaturated pheromone analogues 4 and 5 have been performed by ab initio calculations using Gaussian 92. Two minima were found for a cisoid and a transoid conformer, differing for 0.03 kcal/mol only. Conformational energies of diene analogues (5Z,7E)-5,7-decadienyl acetate (4) and (3E,5Z)-3,5,-decadienyl acetate (5) were determined for conformers required to mimic spatial relationships of the cisoid conformation of the natural pheromone 2. Finally, single sensillum recording studies were carried out with chain elongated C11- to C16-pheromone analogues 6.

N,N-dimethyluracil and actinidine, two pheromones of the ponerine antMegaponera foetens (Fab.) (Hymenoptera: Formicidae).

By means of gas chromatographic, mass spectrometric, and micro-preparative methodsN,N-dimethyluracil and actinidine were identified as two ethologically active compounds in the ponerine antMegaponera foetens. The synthesized poison gland compoundN,N-dimethyluracil released trail-following behavior, whereas actinidine, found in the pygidial gland, stimulated ants to leave the nest, possibly in an alarm reaction. Biological activity of the synthetic samples were confirmed by behavioral experiments and electroantennogram responses with worker antennae.

Identification and characterization of inhibitors of peptido-leukotriene-synthesis from Petasites hybridus.

Extracts from Petasites hybridus were found to inhibit peptido-leukotriene biosynthesis in isolated peritoneal macrophages. Chemical analysis by gas chromatography coupled with mass and infrared spectroscopy facilitated the identification of three isomeric oxopetasan esters, petasin, and isopetasin as the main compounds of these extracts. Fractionations obtained by column chromatography of the most effective extract indicated a correlation between peptido-leukotriene biosynthesis inhibition and the content of isopetasin, a sesquiterpene ester of isopetasol and angelic acid, as well as the isomeric oxopetasan esters. Petasin, a structural isomer of isopetasin, however, was found to be inactive. It may even reduce the peptido-leukotrine inhibitory effect of isopetasin. It is concluded that isopetasin and the oxopetasan esters in Petasites hybridus inhibit the biosynthesis of the vasoconstrictive peptido-leukotrienes. This effect may contribute to some of the medicinal properties of Petasites hybridus extracts such as, e.g., gastroprotection and spasmolytic activity.

Gas chromatographic-mass spectrometric determination of leukotriene E4 in human urine using deuterium-labelled leukotriene E4 standards.

The utility of two deuterium-labelled leukotriene (LT) E4 analogs, e.g. [20,20,20-2H3]LTE4 and [14,15,17,17,18,18-2H6]LTE4, as internal standards for the determination of LTE4 in human urine by gas chromatography-mass spectrometry (GC-MS) was investigated. 2H-Exchange during hydrogenation occurred both in [20,20,20-2H3]LTE4 and [14,15,17,17,18,18-2H6]LTE4 in an extent of 9.4 +/- 0.5% and 67.3 +/- 0.6% (mean +/- S.D., n = 6), respectively. The lower extent of 2H-exchange in [20,20,20-2H3]LTE4 allowed a more accurate quantitation than the use of [14,15,17,17,18,18-2H6]LTE4. Applying [20,20,20-2H3]LTE4 as internal standard the coefficients of variation for the intra- and inter-assay determination of LTE4 in human urine were 5.7% and 6.2% (n = 4), respectively. The inter-assay coefficient of variation for [14,15,17,17,18,18-2H6]LTE4 was 15%. Using [20,20,20-2H3]LTE4 as internal standard and GC-MS, healthy volunteers were found to excrete 17 +/- 10 nmol LTE4 per mol creatinine (mean +/- S.D., n = 11). Similar excretion rates for LTE4 in urine of healthy volunteers were found using GC-tandem MS with [1,1-18O2]LTE4 as internal standard. Our results demonstrate that [20,20,20(-2)H3]LTE4 is a suitable internal standard for the GC-MS determination of urinary LTE4.

Chemical Varieties of Essential Oils from Elsholtzia polystachya from Two Different Locations in India1.

Capillary GC, GC-MS, IR, GC-IR, (1)H- and (13)C-NMR studies of the essential oil from the leaves and cones of ELSHOLTZIA POLYSTACHYA collected from two different locations in India revealed that one oil contained 1,8-cineol (37.3%), the other one perillene (61.2%) as the main constituent.

Syntheses of leukotriene-derivatives.

Some general synthetic routes for the synthesis of cysteinyl-leukotriene derivatives derived from stable building blocks are described. D6-LTE4, a metabolically stable isotopically labelled mass spectrometric internal standard, 20-hydroxy-LTE4, the unnatural 6-epi-LTE4; LTE3, a LT-derivative with 2-amino-thiophenol as a modified "amino-acid" and 14,15-dehydro-LTA4 were prepared. The compounds were tested in a LT-inhibition assay using a monoclonal antibody.

A monoclonal antibody against the sulfidopeptide leukotrienes LTC4, LTD4 and LTE4.

A monoclonal antibody (1A-LDR1) against sulfidopeptide leukotrienes (LT) is described. The mAb shows a nearly identical detection limit of about 0.04 ng for LTC4, LTD4, LTE4 and NacLTE4 in standard fluid phase RIA. Steric modifications, however, diminish the sensitivity, as determined for the examples 5-epi-LTC4, 6-epi-LTC4, 5,6-epi-LTC4 and 11-trans-LTC4. No crossreactivity could be observed for LTB4. Crossreactions with components of the LT peptide chain such as L-cysteine or glutathione, as well as with arachidonic acid, were not detectable. In assessing the accuracy of the LT-RIA, recovery experiments with supernatants of mouse peritoneal macrophages and incubates of gastric mucosa showed a good correlation of r = 0.993 and 0.990, respectively. Results of an inhibition experiment with mouse peritoneal macrophages, incubated with several concentrations of indomethacin and nordihydroguaiaretic acid (NDGA), support the reliability of RIA and ELISA. The new LT-mAB allows an almost complete detection of peptide leukotrienes in one assay.

Chemical composition and function of metapleural gland secretion of the ant,Crematogaster deformis smith (hymenoptera: Myrmicinae).

The secretion of the hypertrophied metapleural gland of the antCrematogaster deformis contains a mixture of phenols, consisting mainly of 3-propylphenol, 3-pentylphenol, 3,4-dihydro-8-hydroxy-3-methylisocoumarin (mellein), 5-propylresorcinol, and 5-pentylresorcinol. The secretion is released, as a repellent, when the highly vulnerable petiolar-postpetiolar region of the abdomen is attacked by enemy ants. In addition, small amounts of the secretion are released regularly to serve as an antiseptic, which is considered the original function of the gland. The secretion also has some insecticidal properties.

Sex pheromone of femaleMyelois cribrella Hübner (Lepidoptera: Pyralidae) : Chemical identification, electrophysiological evaluation, and field attractancy tests.

Females ofMyelois cribrella contain about 20 ng/gland of the primary sex pheromone components (Z)-9-tetradecenyl acetate, (9Z,12E)-9,12-tetradecadienyl acetate, and (Z)-11-hexadecenyl acetate in proportions of 4∶11∶5, respectively. These physiologically active components are accompanied by a number of related compounds such as (Z)-9-tetradecen-1-ol, hexadecyl acetate, (9Z,12E)-9,12-tetradecadien-1-ol, (Z)-11-hexadecen-1-ol, octadecyl acetate, octadecan-1-ol, and eicosyl and docosyl acetates. Octadecyl acetate, the most abundant component, represents about 42 ng/female moth; however, no physiological activity could be attributed to it. In field tests, a trap baited with a 1-mg mixture of (Z)-9-tetradecenyl acetate, (9Z,12E)-9,12-tetradecadienyl acetate, and (Z)-11-hexadecenyl acetate in a ratio of 1∶2∶1 caught more male moths than three live female moths.