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The complete assignment of the proton and carbon chemical shifts of 6-O-acetyl-2,3,4-tri-O-(3S-methylpentanoyl)-α-D-glucopyranosyl-β-D-fructofuranoside, a naturally occurring flavor precursor of tobacco, is presented. These assignments were made by comparison of the spectra obtained from 1H-detected heteronuclear multiple quantum coherence and 1H-detected heteronuclear multiple-bond connectivity two-dimensional NMR experiments.

(...) The structures of fraction I SE contained one acetic acid group esterified to the fructose moiety in addition to three other aliphatic acids on the glucose portion of the sucrose, while fraction II SE only contained three aliphatic acids esterified to hydroxyl groups on the glucose moiety of the sucrose molecule

In this paper, the isolation of two pentacyclic triterpenoids from the storage root of Centennial and the spectral evidence leading to the elucidation of their structures are presented

A method for the determination of testosterone and its metabolite, 6beta-hydroxytestosterone, in liver microsomal incubates employing gas chromatography with selected ion monitoring mass spectrometric detection (GC-SIM-MS) has been developed. The method is more rapid than previously reported methods. Testosterone and its metabolites are extracted from the incubation mixture in a single step with methylene chloride. The method does not require derivatization and testosterone and its metabolites are separated on a HP-5MS fused-silica capillary column in less than 15 min. The retention times of testosterone (m/z 288), methyltestosterone (m/z 302), and 6beta-hydroxytestosterone (m/z 304) are approximately 12.7, 12.8, and 13.4 min, respectively. There are no interferences from other known CYP450 metabolites of testosterone. In addition, the selectivity and specificity of the mass spectrometer helps eliminate possible interferences from drugs and new chemical entities evaluated using this methodology. Calibration curves for testosterone and 6beta-hydroxytestosterone are linear from 0.25 to 100 microM. Extraction recoveries are better than 92% for both analytes and the internal standard, methyltestosterone. Over the course of five separate runs, within-day and inter-day precision (expressed as relative standard deviation) was less than 5% for all concentrations of testosterone and 6beta-hydroxytestosterone. Accuracies ranged from 95.8 to 105.8% for testosterone and 94.6 to 104.2% for 6beta-hydroxytestosterone. The assay has been used to characterize the CYP3A metabolic activity of multiple preparations of human, rat, and dog liver microsomes.

Surface chemicals of green tobacco leaf were obtained by dipping the leaf into methylene chloride. Leaf wash procedures were developed and evaluated for both small and large numbers of samples. Cuticular constituents containing alcohol functions were derivatized with trimethylsilyl reagents and analyzed by glass capillary gas chromatography on SE-54 columns. Quantitative data were obtained for the major cuticular diterpenoids a- and fl-4,8,13-duvatriene-l-ols, a- and j3-4,8,13-duvatriene-l,3-diols, cis-abienol, labda-13-ene-8,15-diol, and docosanol, hydrocarbons, and sucrose esters. The application of this method allowed the characterization of the cuticular constituents of numerous tobacco varieties and introductions. The relationships between cuticular composition and insect resistance are presented and discussed. The green leaves of commercial tobacco varieties are covered with a gummy exudate, and the composition of these cuticular waxes may be of significant importance. Dietrich and Demole (1977) and Enzell (1977) have reported that the degradation of the cuticular diterpenoids of green tobacco, during curing and aging, results in the production of numerous volatile terpenes, which may be important tobacco flavor components. Reid (1975) reported that a diterpene fraction, isolated from green leaf cuticular waxes, contained precursors of aroma constituents of commercial tobacco. Cutler et al. (1977) have found that the cuticular diterpenes of green tobaccos have plant growth inhibiting properties. The levels of specific cuticular components are believed to be responsible for the observed resistances of some types of tobacco to green peach aphids [Myzus persicae (Sulzer)], tobacco budworm [Heliothis uirescens (F.)], and tobacco hornworm [Muduca sextu (L.)] (Johnson and Severson, 1982,1984; Severson

A rapid, economical method was developed for the evaluation of the potential of different tobacco varieties to produce possibly hazardous smoke compounds. This controlled pyrolysis method produces pyrolyzate fractions very nearly identical with corresponding cigarette smoke fractions, as determined by analyses of their polynuclear aromatic hydrocarbons, neutral constituents, and phenolic contents.

The wax ester isolate consisted of a series of C 36 -C 56 homologues, with the C 40 , C 42 , C 44 , C 46 , and C 48 homologues predominating. The major wax ester fatty acids were C 16 , C 18 , C 20 , C 22 , and C 24 . Similar trends in carbon number distribution were found between free and bound fatty alcohols, with the C 22 , C 24 , C 26 , C 28 , C 30 , and C 32 homologues predominating

This work was done as part of a study of the pharmacokinetics and toxicokinetics of GX-071 (N-ethylperfluoro-octanesulfonamide) to support its registration as a pesticide. GX-071 and its major metabolite were identified in the blood of rats and dogs that had been given oral doses of GX-071

Isolement de 2 nouveaux metabolites d'A. ustus, leur structure moleculaire est precisee. On etudie leur activite biologique sur le coleophile de ble (inhibition de la croissance), sur les cultures bacteriennes (Bacillus subtilis et Escherichia coli) sur le poussin (hyperacusie)

Composition des sclerotes de C. purpura provenant de fetuques elevees, orges ou bles. Comparaison des resultats avec les alcaloides trouves dans les feuilles de fetuques infectees par l'endophyte Sphacetia typhina