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.

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.

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.

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.

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.

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.

Identification of sex pheromone components ofSpodoptera sunia Guenée (Lepidoptera: Noctuidae).

Moths belonging to the speciesSpodoptera sunia have been recognized as a new pest of cotton in Central America. By means of electro-physiologic investigations, solid sample injection gas chromatography, and combined gas chromatography-mass spectrometry, (Z)-9-tetradecenyl acetate, (9Z,12E)-9,12-tetradecadienyl acetate, (Z)-9-tetradecen-1-ol, and (Z)-11-hexadecenyl acetate, in a ratio of 100∶5∶31∶20, were identified in the pheromone gland of female insects. These substances should serve as a base for the development of a pheromone-monitoring system for this lepidopteran pest.

Terpenoids from Elsholtzia Species; II1. Constituents of Essential Oil from a New Chemotype of Elsholtzia cristata.

Capillary GC, GC-MS, (1)H-, and (13)C-NMR spectroscopy revealed that the essential oil of ELSHOLTZIA CRISTATA Willd. growing in the Kumaun region contains 88% dehydroelsholtzia ketone along with some minor acylfuran derivatives. This species with respect to its oil composition is unlike that which grows in Japan and Kashmir, and contains elsholtzia ketone as the main constituent.

Technique for injecting intact glands for analysis of sex pheromones of Lepidoptera by capillary gas chromatography : Reinvestigation of pheromone complex ofMamestra brassicae.

The structure elucidation of sex pheromones of Lepidoptera by a solid-sample injection technique in conjunction with capillary gas chromatography is described. The applicability of this method in GC and GC-MS modes was demonstrated by reanalyzing the sex attractants of females ofOstrinia nubilalis andBombyx mori. The pheromone complex ofMamestra brassicae was reinvestigated and (Z)-9-hexadecenyl acetate and (Z)-11-hexadecenol were found in addition to already known pheromone components of this species. By using the solid-sample injection, the exact site of pheromone release could be determined inM. brassicae.

Methyl enol ethers as artefacts in capillary gas chromatographic profiles of aldehyde dimethyl acetals.

Methyl enol ethers are detected within the capillary gas chromatographic profiles of aldehyde dimethyl acetals derived from human red cell plasmalogens or from a synthetic aldehyde mixture. They arise from the dimethyl acetals via methanol elimination as artefacts of the injection technique. In a nutritional experiment, the probands showed a rising proportion of dimethyl acetals in the phospholipid fraction of their erythrocyte ghosts; this fact is seen as an effect of the lipid composition of the milk fat administered.

Constituents of Essential Oil of Elsholtzia strobilifera1.

The composition of the essential oil of ELSHOLTZIA STROBILIFERA, growing around Naini Tal (India) has been investigated by capillary gas-chromatography, gas-chromatography-mass spectrometry and (13)C-NMR spectroscopy. Out of about 50 identified mono- and sesquiterpenoids, pinocarvone is the most abundant component, which has not been identified in any species of ELSHOLTZIA before. The acylfuran derivatives reported from other species of ELSHOLTZIA could not be detected.

[Male sex pheromones of noctuides (author's transl)]. / Pheromone XII. Männchenduftstoffe von Noctuiden (Lepidoptera).

By gaschromatographic-mass spectrometric methods 2-phenylethyl alcohol, benzylalcohol, phenylacetaldehyde and benzaldehyde were identified from scent brushes of male Noctuidae species (Lepidoptera).