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1.
The predominating flavour compounds in the fruit pulp of Durio zibethinus were hydrogen sulfide, ethyl hydrodisulfide and several dialkyl polysulfides, particularly (C2H5)2Sn, where n = 2 or 3. Ethyl acetate, 1,1-diethoxyethane and ethyl 2-methylbutanoate contribute to an additional fruity odour note. Hydrodisulfides are probably the precursors of the dialkyl sulfides. In the pericarp and seed no volatile sulfur compounds could be detected. The fatty acid composition of the lipids in pericarp, pulp and seed depended on the origin and/or harvest season of the fruit. The main components were oleic and palmitic acids or arachidic acid together with appreciable quantities of palmitoleic, stearic, linoleic and linolenic acids. 相似文献
2.
《Biochemical Systematics and Ecology》2005,33(8):757-769
Chemistry of Dufour glands associated with the venom complex in Bracon cephi (Gahan) and Bracon lissogaster Muesebeck (Hymenoptera; Braconidae), two parasitoids of the wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), was examined by solid phase micro-extraction (SPME) and gas chromatography/mass spectrometry. Homologous series of five chemical classes were detected in individual glands from each species. Major classes included: (1) acetate esters of saturated and unsaturated primary alcohols with parent chain lengths from C12 to C20. Hexadecanyl acetate, octadecanyl acetate, and octadecenyl acetate were major components in B. cephi. The composition of the acetate series in B. lissogaster was similar except that the octadecanyl acetate was only a minor component. (2) A homologous series of monoenes from C23:1 to C35:1 were detected in both species, with C29:1, C31:1 and C33:1 being the major components. Dienes from C31:2 to C35:2 and trienes (C33:3–C35:3) were also detected in both species. (3) A homologous series of n-alkanes from C19 to C31 was detected in both species. n-Tricosane was the major component. Minor components in both species included homologous series of both mono- and dimethyl branched alkanes. The Dufour gland hydrocarbon components in both B. cephi and B. lissogaster have some similarities to the composition of cuticular hydrocarbons of their host C. cinctus, a species with a complex pheromonal signaling system. 相似文献
3.
Structure and Biosynthesis of Cuticular Lipids: Hydroxylation of Palmitic Acid and Decarboxylation of C(28), C(30), and C(32) Acids in Vicia faba Flowers
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The structure and composition of the cutin monomers from the flower petals of Vicia faba were determined by hydrogenolysis (LiAlH4) or deuterolysis (LiAlD4) followed by thin layer chromatography and combined gas-liquid chromatography and mass spectrometry. The major components were 10, 16-dihydroxyhexadecanoic acid (79.8%), 9, 16-dihydroxyhexadecanoic acid (4.2%), 16-hydroxyhexadecanoic acid (4.2%), 18-hydroxyoctadecanoic acid (1.6%), and hexadecanoic acid (2.4%). These results show that flower petal cutin is very similar to leaf cutin of V. faba. Developing petals readily incorporated exogenous [1-14C]palmitic acid into cutin. Direct conversion of the exogeneous acid into 16-hydroxyhexadecanoic acid, 10, 16-dihydroxy-, and 9, 16-dihydroxyhexadecanoic acid was demonstrated by radio gas-liquid chromatography of their chemical degradation products. About 1% of the exogenous [1-14C]palmitic acid was incorporated into C27, C29, and C31n-alkanes, which were identified by combined gas-liquid chromatography and mass spectrometry as the major components of the hydrocarbons of V. faba flowers. The radioactivity distribution among these three alkanes (C27, 15%; C29, 48%; C31, 38%) was similar to the per cent composition of the alkanes (C27, 12%; C29, 43%; C31, 44%). [1-14C]Stearic acid was also incorporated into C27, C29, and C31n-alkanes in good yield (3%). Trichloroacetate, which has been postulated to be an inhibitor of fatty acid elongation, inhibited the conversion of [1-14C]stearic acid to alkanes, and the inhibition was greatest for the longer alkanes. Developing flower petals also incorporated exogenous C28, C30, and C32 acids into alkanes in 0.5% to 5% yields. [G-3H]n-octacosanoic acid (C28) was incorporated into C27, C29, and C31n-alkanes. [G-3H]n-triacontanoic acid (C30) was incorporated mainly into C29 and C31 alkanes, whereas [9, 10, 11-3H]n-dotriacontanoic acid (C32) was converted mainly to C31 alkane. Trichloroacetate inhibited the conversion of the exogenous acids into alkanes with carbon chains longer than the exogenous acid, and at the same time increased the amount of the direct decarboxylation product formed. These results clearly demonstrate direct decarboxylation as well as elongation and decarboxylation of exogenous fatty acids, and thus constitute the most direct evidence thus far obtained for an elongation-decarboxylation mechanism for the biosynthesis of alkanes. 相似文献
4.
Onion aphid (Neotoxoptera formosana) attractants, in the headspace of Allium fistulosum and A. tuberosum leaves 总被引:1,自引:0,他引:1
M. Hori 《Journal of Applied Entomology》2007,131(1):8-12
Abstract: Attractancy of Allium fistulosum L. and Allium tuberosum Rottl. to adult apterae of the onion aphid, Neotoxoptera formosana (Takahashi), an oligophagous aphid pest of Allium crops, was investigated with a Y-tube olfactometer. The aphids were significantly attracted to both A. fistulosum and A. tuberosum . The headspace components of both plants were extracted with solid-phase microextraction (SPME) and analysed by gas chromatography-mass spectrometry (GC-MS). The main volatile components of A. fistulosum were dipropyl disulphide (relative contents: 67%), 1-propenyl propyl disulphide (23%) and dipropyl trisulphide (6%). In the headspace of A. tuberosum , diallyl disulphide was detected as the main component (58%). Attractancy of dipropyl disulphide, dipropyl trisulphide and diallyl disulphide to the aphids was examined with the Y-tube olfactometer. The aphids were significantly attracted to dipropyl trisulphide and diallyl disulphide at a concentration of 0.01%. Dipropyl disulphide did not significantly attract the aphids at any concentrations tested. It was revealed that attractancy of A. fistulosum and A. tuberosum was caused by dipropyl trisulphide and diallyl disulphide, respectively. The findings suggest that N. formosana uses these sulphur compounds, characteristic components of Allium plants, as olfactory cues to find the host plants. 相似文献
5.
Jean-Pierre Bianchini Auguste Ralaimanarivo Emile M. Gaydou Bernard Waegell 《Phytochemistry》1982,21(8):1981-1987
The composition of the unsaponifiable matter of the lipids of six Adansonia species (A. grandidieri, A. za, A. fony, A. madagascariensis, A. digitata and A. suarezensis) was investigated. The total unsaponifiable content, its general composition and the identity of the components of the hydrocarbon, sterol and tocopherol fractions are presented. The unsaponifiable content in oil ranges from 0.4 to 1.1% (hexane method) and from 0.6 to 2.2% (diethyl ether method). In two species (A. grandidieri and A. suarezensis) the major components are 4-demethylsterols (23–42%) tocopherols (37-10%) and hydrocarbons (15–17%). In both species examined, eight 4-demethylsterols occur in the sterol fraction with sitosterol (81–88%) being predominant. Among the four tocopherols present, γ-tocopherol (68–98%) is the major compound. Each Adansonia species shows a characteristic gas liquid chromatography pattern for the hydrocarbon fraction. Squalene is the major component for five species (40–75%). Iso-, anteiso- and other branched hydrocarbons were not identified but were present in small amounts in comparison with n-alkanes. The dominance of odd- over even-carbon number chain length of n-alkanes was not observed in any species. The results show that C22, C25, C26, C27, C28 and C29 are the most frequent major constituents. 相似文献
6.
Sulphur-containing “perfumes” attract flower-visiting bats 总被引:7,自引:0,他引:7
O. von Helversen L. Winkler H. J. Bestmann 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2000,186(2):143-153
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.
Accepted: 9 November 1999 相似文献
7.
In order to study the effect of light on the tobacco tissue culture WR-132, 5 passages (10 days' growth per passage) of these cells were grown in darkness, and 3 passages were separately grown in intense light (16000 lx). All other growth conditions were the same. The resulting isoperoxidase patterns present in these cells and in their growth media were analyzed at 2-day intervals during this period and then compared with the isoperoxidase patterns of cells grown under dim light conditions (10 lx). A new cathodic isoperoxidase (Cn) appeared in the medium within 2 days after the cells were placed in the dark. Cn was present in all media of WR-132 cell cultures analyzed throughout the 5 passages grown in darkness. The fifth passage in darkness produced total cessation of growth (apparent death). Cn increased and new anodic isoperoxidases Aa, Ab, Ad and Ae appeared in the media as the cells approached death in darkness. 相似文献
8.
《Comparative biochemistry and physiology. B, Comparative biochemistry》1994,107(2-3):293-303
The total surface lipids, including the wax particles, of the adult whiteflies of Bemisia tabaci and Trialeurodes vaporariorum were characterized. At eclosion, there were similar amounts of long-chain hydrocarbons, aldehydes, alcohols and wax esters. Within a few hours post-eclosion, long-chain aldehydes and long-chain alcohols were the dominant surface lipid components, C34 on B. tabaci and C32 on T. vaporariorum. Hydrocarbons, mainly n-alkanes, were minor components of the surface lipids. The major wax esters were C46 on B. tabaci and C42 on T. vaporariorum. The major acid and alcohol moieties in the wax esters of B. tabaci were C20 and C26, respectively, and of T. vaporariorum were C20 and C22, respectively. Both B. tabaci and T. vaporariorum had a minor wax ester composed of the fatty acid C18:1 esterified to the major alcohols, C34 and C32, respectively. Bemisia were readily distinguished from Trialeurodes based on the composition of their wax particles and/or their wax esters; however, no differentiating surface lipid components were detected between biotypes A and B of B. tabaci. 相似文献
9.
Dennis E. Briggs 《Phytochemistry》1974,13(6):987-996
Material from the testa of decorticated barley grains contained hydrocarbons, esters, triglycerides, free sterols, 5-n-alkylresorcinols, and traces of free alcohols, carbonyl compounds, and various polar, acidic materials. The hydrocarbon fraction was mainly a series of n-alkanes, extending at least from C11 to C36, in which the C29 and C31 components were prominent. Two minor series of alkanes were also present. Sometimes a trace of an unsaturated hydrocarbon was detected. The ester fraction contained sterols and alkanols esterified by fatty acids, which differed in relative amounts from the fatty acids found in the triglycerides. The triglycerides were thought to have leached from within the grain. At least five free sterols were present, including sitosterol and campesterol. The 5-n-alkylresorcinols were at least twelve members of a homologous series, of which four, C25, C27, C29, and C31, made 98% of the total. Members of the series with even numbers of carbon atoms were also present. It is suggested that they are partly responsible for excluding microorganisms from the interior of the grain. The testa membrane, with the associated pigment strand, contained an estolide of fatty acids and various hydroxyacids, a polysaccharide component, and uncharacterized material. 相似文献
10.
The sterols of Clerodendrum splendens, an angiosperm belonging to the family Verbenaceae, were found to possess a 24β-ethyl group. No other sterols were detected. The major sterol was 24β-ethylcholesta-5,22E,25(27)-trien-3β-ol [also known as 25(27)-dehydroporiferasterol]. A very small amount of what may have been its 22-dihydroderivative, clerosterol [also known as 25(27)-dehydroclionasterol] was also found. The dominant n-alkane was C29 (n-nonacosane) and the dominant n-alkanol was C28 (n-octacosanol). 相似文献
11.
This is the first report devoted to study of the hydrocarbon composition of the extract of buds of European birch Betula pendula (family Betulacea). We have identified saturated (C16 to C28, even number of carbon atoms) and unsaturated (linoleic and linolenic) fatty acids, β-caryophyllene, α-humulene, and the components of epicuticular waxes of cover scales, such as n-alkanes (C21 to C26), esters of fatty acids (C16 to C28, even number of carbon atoms), and fatty alcohols (C18 to C30, even number of carbon atoms). The gas chromatographic retention indices of all identified compounds have been determined. 相似文献
12.
The volatile Dufour's gland components of Pogonomyrmex rugosus and P. barbatus have been examined and found to be hydrocarbons. Homologous families of alkanes from this gland consisted of normal hydrocarbons ranging from n-dodecane to n-pentadecane and three types of methyl-branched homologues of the general formula CnH2n+1CH(CH3)CmH2m+1, where n is 2, 4, or 5 and the sum of n and m is 10, 11, 12, or 13. The dimethyl-branched hydrocarbons 3,5-dimethyldodecane and 3,4-dimethyltridecane were also observed. 相似文献
13.
《Lichenologist (London, England)》1996,28(1):79-87
Surface alkanes were extracted from thalli of populations ofXanthoria parietinagrowing in two different Piedmont (Italy) valleys: Susa and Vermenagna. The mainn-alkanes detected in the Susa Valley were C27, C28, C29and C31, whereas C25, C27and C29were the most abundant in Vermenagna Valley. The results indicate that then-alkane qualitative composition ofX. parietinawas affected both by elevation and climatic characteristics typical of the two valleys considered. 相似文献
14.
- 1.1. The cuticular hydrocarbon mixture of Blaps mucronata comprises n-alkanes (C23 to C29, 41%), 3-methylalkanes (C24 to C32, 29%) and internally branches monomethylalkanes (C24 to C36, 11%) and dimethylalkanes (C32 to C37, 15%).
- 2.2. B. mucronata is distinguished from six other tenebrionid species by the qualitative and quantitative characteristics of its hydrocarbon mixture.
15.
The leaf alkanes of Parthenium argentatum (guayule), P. tomentosum var. stramonium, P. fruticosum var. trilobatum, and the first filial (F1) generations obtained from crosses with guayule were investigated by GC and mass spectrometry and shown to be useful in chemotaxonomic studies. The identified n-alkanes ranged from C19 to C40 with either n-C29 or n-C31 as the main component. The alkane chemistry of guayule with n-C31 being the main component predominated in most of the F1 hybrids. The presence of iso-branched alkanes (C27, C29, C31) in P. tomentosum and its hybrids could be detected by GC/MS. These preliminary investigations indicate that epicuticular wax alkanes can be useful in inheritance studies of guayule and its hybrids. 相似文献
16.
A waxy fraction obtained by column chromatography of the essential oil of Cannabis sativa consists of n-alkanes ranging from C9 to C39, 2-methyl and 3-methyl alkanes and some dimethyl alkanes. The qualitative and quantitative composition of this fraction has been compared with the alkane fraction obtained by extraction of the herb. 相似文献
17.
The composition of the n-alkanes in the leaf waxes of over 80 clones of Saccharum officinarum, S. edule, S. robustum, S. spontaneum and from a number of related species have been compared by GLC. The waxes contain predominantly odd alkanes, C27–C35, the major components being C29 and C31. In a number of clones, particularly of S. edule, a homologous series of alkenes was also present. No chemotaxonomic relationship could be derived from the compositions as the intraspecific variation was greater than the interspecific variations. 相似文献
18.
Analysis of alkane-dependent methanogenic community derived from production water of a high-temperature petroleum reservoir 总被引:1,自引:0,他引:1
Mbadinga SM Li KP Zhou L Wang LY Yang SZ Liu JF Gu JD Mu BZ 《Applied microbiology and biotechnology》2012,96(2):531-542
Microbial assemblage in an n-alkanes-dependent thermophilic methanogenic enrichment cultures derived from production waters of a high-temperature petroleum reservoir was investigated in this study. Substantially higher amounts of methane were generated from the enrichment cultures incubated at 55 °C for 528 days with a mixture of long-chain n-alkanes (C15–C20). Stoichiometric estimation showed that alkanes-dependent methanogenesis accounted for about 19.8% of the total amount of methane expected. Hydrogen was occasionally detected together with methane in the gas phase of the cultures. Chemical analysis of the liquid cultures resulted only in low concentrations of acetate and formate. Phylogenetic analysis of the enrichment revealed the presence of several bacterial taxa related to Firmicutes, Thermodesulfobiaceae, Thermotogaceae, Nitrospiraceae, Dictyoglomaceae, Candidate division OP8 and others without close cultured representatives, and Archaea predominantly related to uncultured members in the order Archaeoglobales and CO2-reducing methanogens. Screening of genomic DNA retrieved from the alkanes-amended enrichment cultures also suggested the presence of new alkylsuccinate synthase alpha-subunit (assA) homologues. These findings suggest the presence of poorly characterized (putative) anaerobic n-alkanes degraders in the thermophilic methanogenic enrichment cultures. Our results indicate that methanogenesis of alkanes under thermophilic condition is likely to proceed via syntrophic acetate and/or formate oxidation linked with hydrogenotrophic methanogenesis. 相似文献
19.
Thomas G. Waddell Mark H. Thomasson Michael W. Moore Houston W. White Dorothy Swanson-Bean Margaret E. Green Gene S. Van Horn Henry M. Fales 《Phytochemistry》1982,21(7):1631-1633
The hexane extract of Wyethia mollis contains the n-alkanes C15-C18, C20-C25, C27 and C29. Linoleic acid was the only detectable acidic component. A mass spectral analysis of the wax ester fraction indicated that it was a mixture of homologues, the saturated even-carbon acids n-C16-C30 esterfield with the saturated even-carbon alcohols n-C18-C26. The chloroform extract yielded the known isoflavones santal and 3′-O-methylorobol along with a new lanostane-type triterpene, 22,25-epoxy-lanosta-7:9(11)-dien-3-one. The wide distribution of n-alkanes and the decreased odd-even carbon ratio are consistent with the proposed primitive nature of this plant. 相似文献
20.
Two isoperoxidases (Af and Cn) from the medium of tobacco tissue suspension culture WR-132 grown in darkness have been purified to apparent homogeneity and partially characterized. Cn and Af have MWs of ca 30 000 and 54 000, respectively. Af has ca 5.1% carbohydrate, but none could be detected in Cn. Both isoperoxidases appear to follow simple Michaelis-Menten kinetics with respect to guaiacol as the substrate. The Kms for guaiacol are 4 and 13.3 mM for Af and Cn, respectively, while both isoperoxidases have a pH optimum at 6.5. Cn, is dissimilar to other isoperoxidases from tobacco tissue cultures, but Af is very similar to isoperoxidase A3 from W-38 tobacco tissue culture. 相似文献