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Selected AbstractsEnantiomeric composition of (E)- and (Z)-sabinene hydrate and their acetates in ,ve Origanum spp.FLAVOUR AND FRAGRANCE JOURNAL, Issue 2 2005Olga Larkov Abstract The enantiomers of (E)- and (Z)-sabinene hydrate and of (E)- and (Z)-sabinene hydrate acetate from extracts of Origanum ramonense Danin, O. dayi Post, O. majorana L., O. vulgare L. ssp. vulgare and O. syriacum L. ssp. syriacum were analysed by GC,MS with chiral and non-chiral capillary columns. The order of elution, the enantiomeric ratios and relative percentages of the four pairs of enantiomers were determined. The (1S)-enantiomers of (E)-sabinene hydrate and (E)-sabinene hydrate acetate were predominant in O. dayi, whereas in the other Origanum spp. the (1R)-enantiomers were predominant. (Z)-sabinene hydrate acetate was not detected in O. syriacum, while the (1R)-enantiomer was present in an optically pure form in O. ramonense, O. majorana and O. vulgare; in O. dayi the enantiomeric purity was 97%. The enantiomeric distributions of (E)- and (Z)-sabinene hydrate and their acetates were determined for the ,rst time in Origanum spp. Copyright © 2004 John Wiley & Sons, Ltd. [source] Determination of essential oil quality index by using energy summation indices in an elite strain of Cymbopogon citratus (DC) Stapf [RRL(J)CCA12]FLAVOUR AND FRAGRANCE JOURNAL, Issue 2 2005Ashok Kumar Shahi Abstract Out of the several accessions of Cymbopogon citratus (DC) Stapf introduced from Central and West India, one accession coded as RRL(J)CCA12, selected through a mass selection technique, was found to have citral (,80%) as the major constituent in its essential oil. Citral has tremendous application in the ,avour and perfume industries. Plant adaptation was judged by quantifying the regression coef,cient (b) value, which was 1.0 using essential oil growth indices. For prediction of essential oil quality index (EOQI), a multiple regression equation was developed for the ,rst time by using essential oil yield/plant and energy summation indices as EOQI (citral %) = 61.6 + 1.09 × essential oil yield/plant (g) - 0.005 × heat use ef,ciency + 0.675 × phenothermal index. For obtaining a better quality of essential oil (citral ,78%), the optimal value of independent variable would be: X1 = 2.49; X2 = 0.018 and X3 = 20.47, where X1, X2 and X3 denote essential oil yield/plant, heat use ef,ciency and phenothermal index, respectively. The validation of the EOQI model is done by correlating the predicted and calculated values of citral (%) which exhibited signi,cant r value = 0.955 at 5% probability level. The thermal requirement of the selectant was ,5500 degree days to exhibit plant maturity in terms of qualitative and quantitative characteristics of its essential oil at 6.0 vegetative lea,ng stage, with attainment of plant height ,1.0 m from previous date of harvest (December 2001). Prediction of essential oil quality by using the mathematical model is helpful for integrating the growth processes and evaluating crop management strategies. Copyright © 2004 John Wiley & Sons, Ltd. [source] Neutral components from hexane extracts of Croton sellowiiFLAVOUR AND FRAGRANCE JOURNAL, Issue 1 2004Sebastiăo F. Palmeira Jr Abstract Qualitative analyses by GC,FID and GC,MS of the neutral fractions from hexane extract of the leaves, stems and roots of Croton sellowii were carried out. Sesquiterpenoids, n -alkanes, aliphatic esters and aliphatic alcohols and alkyl benzene derivatives were identi,ed. Caryophyllene oxide (46.8%) and trans -caryophyllene (40.8%) were most abundant in the leaves, while caryophyllene oxide (26.5%) and cubenol (16.7%) were the main constituents in the stems. In the roots, besides mesitylene (15.2%), the sesquiterpenes , -(7.6%), , -(6.9%) and , -eudesmol (5.5%) were the most abundant components. All identi,ed constituents are described for the ,rst time in this species. Copyright © 2003 John Wiley & Sons, Ltd. [source] Isolation and characterization of several aromatic sesquiterpenes from Commiphora myrrhaFLAVOUR AND FRAGRANCE JOURNAL, Issue 4 2003Nanqun Zhu Abstract The puri,cation and structure characterization of seven aromatic sesquiterpenes from scented Commiphora myrrha are reported. Their structures were determined on the basis of spectral data, especially of NMR evidence. Among them, compound 1 is a new furanosesquiterpene and compound 2 is identi,ed as a new natural aroma found in Commiphora spp. All compounds except 4 were isolated, for the ,rst time, from Commiphora myrrha. Copyright © 2003 John Wiley & Sons, Ltd. [source] The determination of n -alkanes in the cuticular wax of leaves of Ludwigia adscendens L.PHYTOCHEMICAL ANALYSIS, Issue 2 2004A. Barik Abstract An n -hexane extract of fresh, mature leaves of Ludwigia adscendens, containing a thin layer of epicuticular waxes, has been analysed for the ,rst time by TLC, IR and GC using standard hydrocarbons. The leaves contained 22 identi,ed long chain (C15,C36) n -alkanes, accounting for 74.27% of the hydrocarbons present, and an unknown number of unidenti,ed branched chain alkanes. The predominant n -alkane was C25 (11.02%), whilst C18 (7.62%), C20 (6.14%), C29 (5.36%) and C27 (5.29%) n -alkanes were moderately abundant: the C35 homologue was present only in minor amounts (0.22%). Copyright © 2004 John Wiley & Sons, Ltd. [source] Bioactive brominated diterpenes from the marine red alga Jania Rubens (L.) Lamx.PHYTOTHERAPY RESEARCH, Issue 4 2004Nagwa E. Awad Abstract Seven brominated diterpenes of the parguerene and isoparguerene series were isolated for the ,rst time from the red alga Jania rubens (L.) Lamx., collected from the Red Sea coast at Hurghada, Egypt. The diterpenes were identi,ed as isoparguerol (1), isoparguerol-16-acetate (2), isoparguerol-7,16-diacetate (3), parguerol-16-acetate (4), parguerol-7,16-diacetate (5), deoxyparguerol (6) and deoxyparguerol-7-acetate (7). The isolated diterpenes had a marked antitumour activity. Isoparguerol derivatives were slightly more effective than parguerol derivatives. Moreover, the data implied that the cytotoxicity of these compounds were dependent on the number of acetoxy groups. Also, anthelmintic activities of the isolated compounds on earthworms (Allolobophora caliginosa) were studied. Copyright © 2004 John Wiley & Sons, Ltd. [source] The antimicrobial activity of essential oils of Hypericum scabrum, Hypericum scabroides and Hypericum triquetrifoliumPHYTOTHERAPY RESEARCH, Issue 4 2004Göksel K Abstract The essential oils of Hypericum scabrum, Hypericum scabroides and Hypericum triquetrifolium were studied for the ,rst time for their antimicrobial activity against nine organisms. All the essential oils exhibited some broad spectrum antibacterial activity, at a concentration of 80 µg/mL. The essential oils of Hypericum species showed antibacterial activity against the tested organisms and a yeast. Copyright © 2004 John Wiley & Sons, Ltd. [source] Structure determination of oligomeric alkannin and shikonin derivativesBIOMEDICAL CHROMATOGRAPHY, Issue 7 2005Apostolos Spyros Abstract Monomeric alkannin and shikonin (A/S) are potent pharmaceutical substances with a wide spectrum of biological activity and comprise the active ingredients for several pharmaceutical preparations. Therefore, the determination of the impurities, degradation products or byproducts in alkannin and shikonin samples is of great importance. Oligomeric alkannin and shikonin are formed during biosynthesis of these bioactive secondary metabolites in Boraginaceaous root plants, during tissue culture production of A/S, during alkaline hydrolysis of A/S esters and also thermal treatment of A/S. In the present study, a dimeric alkannin/shikonin compound was isolated by size exclusion chromatography from alkannin and shikonin commercial samples and its structure was determined by one- and two-dimensional NMR spectroscopy. The structure of the most abundant oligomeric species in these samples, a dimeric naphthoquinone, was established for the ,rst time, indicating that coupling of the side chain of one naphthoquinone unit with the aromatic ring of a second naphthoquinone leads to dimer formation. This type of coupling allows further oligomerization by leaving one isohexenyl side chain available at the second monomer unit. Copyright © 2005 John Wiley & Sons, Ltd. [source] | ||||||||||