首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 765 毫秒
1.
Fatty acid composition of lipids isolated from spores of different fern groups show differences between the families whereas species variations within the families are smaller. As in seed fats, the spore lipids are mainly triglycerides, with the exception of Osmunda where free fatty acids accumulate. The spore lipids contain as major components oleic, linoleic, and palmitic acid although those of the sporophylls contain C-20 polyunsaturated acids.  相似文献   

2.
《Phytochemistry》1987,26(12):3265-3268
Seven species of fresh mangrove leaves were found to contain saturated normal and branched chain hydrocarbons, mostly between C16 and C36 with both odd and even carbon numbers. Significant quantitative variations were found between species. Wax esters were found to contain fatty acids with chain lengths between C12 and C22. Palmitic (16:0) and stearic (18:0) acids were the major component saturated fatty acids, whereas, oleic (18:1) and linolenic (18:3) acids were the major unsaturate α-acids. Chain lengths of the alcohols of wax esters were between C14 and C36. Significant quantitative and minor qualitative differences were noted in the alcohol composition of wax esters. Hydrocarbon and wax ester compositions were characterised by the presence of low M, components in high proportions.  相似文献   

3.
The analysis of fatty acids and hydrocarbons in the sporophytes of three Lycopodium species has revealed a characteristic distribution of C16 and C18 acids. The hydrocarbon fraction of the lipids contain a homologous series of monounsaturated alkenes in the C17C30 range with an even to odd preference. Maxima at both C17 and C27 among the n-alkanes reveals similarities both to the distribution of hydrocarbons in other plant groups. The production of spores and their inclusion with one sporophyte does not alter the fatty acid pattern but does decrease the alkene concentration and modifies the alkane distribution, shifting both maxima. The presence of pristane and phytane in all specimens, the dual maxima of alkanes and slight odd to even preference of alkanes is noteworthy in that these characteristics are possessed by geological deposits derived from Lycopodium ancestors.  相似文献   

4.
Certain fatty acids in the C5 to C18 range, at concentrations as low as 10−5 M, were found to inhibit the germinations of spores of the sensitive fern, Onoclea sensibilis L. The addition of gametophytic culture flltrates of the bracken fern, Pteridium aquilinum (L.) Kuhn, containing antheridogen A, was found to overcome this inhibition and allow the spores to germinate and the gametophytes to develop in a normal fashion. Some fatty acids were found to increase the antheridium-inducing potency of antheridogen A as much as 10-fold. An effect similar to this may promote the diecious reproduction of ferns.  相似文献   

5.
D.R. Body 《Phytochemistry》1974,13(8):1527-1530
The neutral lipids of white clover leaves and stems have been separated into wax esters, free fatty acids, free fatty alcohols, free sterols, triglycerides and hydrocarbons. The wax esters were mainly of C18 di- and tri-unsaturated fatty acids and C30 fatty alcohol. Linolenic acid was the predominant free fatty acid and triacontanol was the principal free fatty alcohol. Of the hydrocarbons, C29 and C31 were present in the largest amounts.  相似文献   

6.
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   

7.
《Phytochemistry》1987,26(5):1441-1445
Seed, kernel or fruit oils of the Cornaceae (nine species). Hydrangea, Hamamelis, Ilex (Aquifoliaceae) and the Styracaceae (two species) were analysed for fatty acid composition. Special attention was paid to the occurrence of petroselinic acid (18: 1Δ6c). In the species investigated. C18 acids were always present in greater quantities than C16 fatty acids; C20 and C22 acids were only minor components. The Cornaceae show differing fatty acid patterns which correlate well with anatomical, morphological and other chemical data. In Cornus, Curtisia, Mastixia and Corokia linoleic acid predominates, whereas linoleic and linolenic acid form the major components in Davidia and Nyssa. 18 : 1Δ6c, an aralioid type, occurs in large amounts in Aucuba and Griselinia. Hamamelis, Hydrangea and Ilex show a common fatty acid pattern with linoleic acid as the dominant component in all cases. Classification currently based on morphological and anatomical differences between the two species of Styracaceae which were investigated here should include their different fatty acid compositions: in Halesia linoleic acid predominates over oleic acid, whereas in Styrax equal amounts of these two acids are found.  相似文献   

8.
Chlorella kessleri cultivated in a deep tank contained 4.8% of non-polar lipid; 51% of this fraction represents saturated fatty acids, 7% unsaturated fatty acids. Our investigation of the fatty acids profile demonstrated even- and odd-numbered saturated and unsaturated fatty acids ranging from C12 to C20. Unlike in otherChlorella species, stearic acid was the dominant fatty acid found. Also shown was an elevated C16:0 fatty acid content and a reduced level of unsaturated fatty acids.  相似文献   

9.
The fatty acid composition of the total lipid fractions of five different Leishmania organisms grown on Eagle's medium was determined by gas chromatography. The major fatty acids identified in the total lipid fractions of L. donovani, L. tropica major, L. tropica minor, L. tropica (England strain), and L. enriettii were C12:0, C13:0, C14:0, C15:0, C16:0, C17:0, C18:0, C18:1, C18:2, and C18:3. The statistical differences among the fatty acid methyl esters of different Leishmania organisms are discussed.Gas chromatographic analysis of the fatty acid methyl esters of the total lipid fractions of the original Eagle's medium and the media after harvesting of various Leishmania species revealed the presence of C18:3 fatty acid in the total lipid fraction of the medium of L. donovani and the complete absence of 18-carbon unsaturated fatty acids in the total lipid fraction of the medium of L. enriettii. The use of such differences in the differentiation of various Leishmania species is discussed.  相似文献   

10.
Addition to Bacillus acidocaldarius of acids which can act as primers for fatty acid synthesis promote the synthesis of corresponding fatty acids competitively. The effective acids are n?C5 to -?7 (not C4 or C8), iso- and anteiso-C, and ?C, (not C4), and a range of cyclic acids from cyclobutylacetic and cyclopentanecarboxylic to cycloheptylacetic. New non-natural ω-cyclobutyl-, ω-cyclopentyl-, and ω-cycloheptyl-fatty acids are obtainable. The range of acceptable primers and the range of fatty acids produced therefrom indicate, respectively, the substrate specificities of the transacylase which introduces acyl species into fatty acids synthesis and the one which removes them. The specificity of the primer transacylase may be similar to that in some rumen anaerobes.  相似文献   

11.
Fatty acid and alcohol components of preen oil were determined in three gull species that belong to two systematic genera: herring gull Larus argentatus, common gull Larus canus and black-headed gull Chroicocephalus ridibundus. All gulls were captured in winter, in Gdańsk, Poland. All gulls produced monoesters composed of C7–C16 saturated fatty acids and C11–C20 saturated alcohols, with n-octanoic acid and n-hexadecanol as the major fatty acid and alcohol, respectively. Preen oils of black-headed gull had higher content of trimethyl fatty acids, 2,8-dimethylundecanoic acid, 2,6-dimethylundecanoic acid and 2,6-dimethylnonanoic acid, and lower content of 2-methyl fatty acids than oils of herring gull and common gull. Preen oils produced by black-headed gull also had lower content of 2-methyl alcohols. The relative contents of n-octanoic acid and n-hexadecanol did not differ among species. The differences among species are probably not a result of different diet, as all gulls fed mainly on household refuse. Hence, preen oil analysis confirmed the taxonomic relations among these gull species, that recently were placed into two different genera.  相似文献   

12.
Fatty Acids of Myxococcus xanthus   总被引:9,自引:4,他引:5       下载免费PDF全文
Fatty acids were extracted from saponified vegetative cells and myxospores of Myxococcus xanthus and examined as the methyl esters by gas-liquid chromatography. The acids consisted mainly of C14 to C17 species. Branched acids predominated, and iso-pentadecanoic acid constituted half or more of the mixture. The other leading component (11–28%) was found to be 11-n-hexadecenoic acid. Among the unsaturated acids were two diunsaturated ones, an n-hexadecadienoic acid and an iso-heptadecadienoic acid. No significant differences between the fatty acid compositions of the vegetative cells and myxospores could be detected. The fatty acid composition of M. xanthus was found to be markedly similar to that of Stigmatella aurantiaca. It is suggested that a fatty acid pattern consisting of a large proportion of iso-branched C15 and C17 acids and a substantial amount of an n-16:1 acid is characteristic of myxobacteria.  相似文献   

13.
The major hydrocarbons of Synechococcus sp., a marine blue-green alga isolated from the Gulf of Mexico, were identified as 1-nonadecene and 1,14-nonadecadiene. The content of 1-nonadecene increased with culture age from about 0.5 mg/g dry weight in young cells to about 2.3 mg/g dry weight in old cells, while the content of 1,14-nonadecadiene remained constant with culture age at about 1 mg/g dry weight. Both [1-14C]acetate and [2-14C]acetate were incorporated to equal extents into the hydrocarbons. [1-14C]Stearate was incorporated into the hydrocarbons, but [3H]arachidate was not. The fatty acids of Synechococcus sp. were typical of blue-green algae, consisting of C16:0, C16:1, C16:1, C16:0, C18:0, C18:1, C18:2 and C18:3 fatty acids were detected. The hexadecenoic acid was shown to be 9-C16:1 while the octadecenoic acid was a mixture of 93% 11-C18:1 and 7% 9-C18:1. The fatty acid content increased during the first 4 days of growth and then decreased slightly.  相似文献   

14.
Summary The hydrocarbon composition ofPseudomonas maltophilia was determined by gas chromatography-mass spectrometry. Mono-, di- and tri-unsaturated alkenes were identified with a predominance of polyunsaturated components. The carbon chains of the alkenes contained single methyl branches iniso andanteiso position and double methyl branches in theiso-iso andanteiso-anteiso configurations. The composition of the hydrocarbons from cells grown in synthetic media enriched with amino acids or volatile fatty acids demonstrated that the probable precursors incorporated into individual hydrocarbons were branched and normal fatty acid chains in the range from C3 to C16. The probable fatty acid precursors which were connected together to form the major triunsaturated hydrocarbon chains were two monounsaturated chains, whereas the major liunsaturated chains resulted from condensation of saturated and monounsaturated chains. The probable precursors for the major monounsaturated hydrocarbons were C14 (C15) and C16 (C15) fatty acids. The accumulation of hydrocarbons was not detected until the cells were in the late exponential phase of growth; the maximal levels were reached at the mid-stationary phase of growth.  相似文献   

15.
Methyl esters of fatty acids, free fatty acids, and hydrocarbons were found in the culture liquid and in the cellular lipids of the obligate methylotrophic bacterium Methylophilus quaylei under optimal growth conditions and osmotic stress. The main extracellular hydrophobic metabolite was methyl stearate. Exogenous free fatty acids C16–C18 and their methyl esters stimulated the M. quaylei growth and survivability, as well as production of exopolysaccharide under osmotic and oxidative stress, playing the role of growth factors and adaptogens. The order of hydrophobic supplements according to the ability to stimulate bacterial growth is C18: 1 > C18: 0 > C16: 0 > methyl oleate > methyl stearate > no supplements > C14: 0 > C12: 0. The mechanism underlying the protective action of fatty acids and their methyl esters is discussed.  相似文献   

16.
The fatty acid composition of the fruit oils or seed oils of Pittosporaceae (eight genera, 10 species), Araliaceae (two species), Simarubaceae (three species), and of one umbelliferous and one rutaceous species were determined by gas chromatography, argentation TLC and ozonolysis. In the Pittosporaceae, in which the major C18 fatty acid of all species was either oleic acid (18:1, 9c) or linoleic acid (18:2, 9c, 12c), large amounts of C20 and C22 fatty acids seem to occur regularly. Petroselinic (18:1, 6c) and tariric (18:1, 6a) acids were absent. However, petroselinic acid was the major fatty acid in the Araliaceae and Umbelliferae. In these two families only small amounts of C20 and C22 acids were detected and tariric acid was absent. The Rutales contained relatively high amounts of trans-octadecenoic acids (18:1, 9t). Tariric acid was the major fatty acid in the two species of Picramnia (Simarubraceae), which also contained small amounts of petroselinic acid. The major fatty acids in Ailanthus glandulosa (Simarubaceae) and Phellodendron amurense (Rutaceae) were linoleic or linolenic acid (18:3, 9c, 12c, 15c); these species contained neither tariric nor petroselinic acid and the levels of C20 and C22 fatty acids were low. The appearance of schizogenous resin canals and polyacetylenes and the absence of iridoids and petroselinic acid allows the Pittosporaceae to be separated from the Rutales and Araliales and to be placed in an independent order, the Pittosporales. Arguments for a rather close relationship of the Pittosporales to the Araliales and Cornales (including the Escalloniaceae) are presented.  相似文献   

17.
《Phytochemistry》1987,26(3):749-752
The esters of n-fatty acids and ω-hydroxy n-fatty acids of β-sitosterol, D-glucose and ferulic acid (trans and cis) as well as β-sitosterol, fatty acids and β-sitosteryl-β-D-glucoside were isolated from three Virola species and identified by optical data and chemical reactions. A novel series of acidic esters derived from C22C29 ω-hydroxy fatty acids and cis- and trans-ferulic acid is reported for the first time. These compounds also occurred as the corresponding diester 1-monoglycerides whereas the ω-hydroxy acids themselves were also present as the corresponding glucosyl esters.  相似文献   

18.
The component sterols, alcohols, hydrocarbons, monocarboxylic, α,ω-dicarboxylic and α- and ω-hydroxy acids from the leaves and roots of the tropical seagrass Thallassia hemprichii are reported. The leaves contained significant concentrations of cholest-5-en-3β-ol, a sterol not normally detected in either higher plants or seagrasses. The lower abundance of polyunsaturated fatty acids found in both the leaves and roots compared to other seagrass species may be a result of the warmer waters from which this species was collected. Solvent-extractable, long-chain (> C22)α,ω-diacids, α- and ω-hydroxy and monocarboxylic acids were also isolated from the leaves. The distribution pattern of these lipids should enable these components along with other distinctive components to be used as chemical markers for this seagrass.  相似文献   

19.
Hiroko Yokokawa 《Phytochemistry》1980,19(12):2615-2618
The simple lipids present in ten species of Polyporaceae (Piptororus betulinus, Coriolus pargamenus, C. versicolor, C. heteromorphus, Formitopsis cytisina, F. pinicola, Microporus flabelliformis, Gloephyllum saepiarium, Crytoderma citrinum and Grifola frondosa) were investigated. The fatty acids that these species had in common were C16-saturated acids (except in P. betulinus) and C18-unsaturated acids. Ergosterol and ergosta-7,22-dien-3β-ol were isolated from these mushrooms. Lupeol was obtained from G. saepiarium. Ergost-7-en-3β-ol, lanosterol and 24-methylene-24,25-dihydrolanosterol were tentatively identified.  相似文献   

20.
Sex pheromones of moths are largely classified into two types based on the presence (Type I) or absence (Type II) of a terminal functional group. While Type-I sex pheromones are synthesized from common fatty acids in the pheromone gland (PG), Type-II sex pheromones are derived from hydrocarbons produced presumably in the oenocytes and transported to the PG via the hemolymph. Recently, a fatty acid transport protein (BmFATP) was identified from the PG of the silkworm Bombyx mori, which produces a Type-I sex pheromone (bombykol). BmFATP was shown to facilitate the uptake of extracellular fatty acids into PG cells for the synthesis of bombykol. To elucidate the presence and function of FATP in the PG of moths that produce Type-II sex pheromones, we explored fatp homologues expressed in the PG of a lichen moth, Eilema japonica, which secretes an alkenyl sex pheromone (Type II). A fatp homologue cloned from E. japonica (Ejfatp) was predominantly expressed in the PG, and its expression is upregulated shortly after eclosion. Functional expression of EjFATP in Escherichia coli enhanced the uptake of long chain fatty acids (C18 and C20), but not pheromone precursor hydrocarbons. To the best of our knowledge, this is the first report of the cloning and functional characterization of a FATP in the PG of a moth producing a Type-II sex pheromone. Although EjFATP is not likely to be involved in the uptake of pheromone precursors in E. japonica, the expression pattern of Ejfatp suggests a role for EjFATP in the PG not directly linked to pheromone biosynthesis.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号