共查询到20条相似文献,搜索用时 15 毫秒
1.
Sterols of both roots and nodules of three species of Alnus were found to consist only of sitosterol, whereas Casuarina cunninghamiana contained substantial amounts of campesterol, stigmasterol and sitosterol. In all four cases more sterol was extracted from nodules than from roots. 相似文献
2.
Sterols of male and female flowers from Ilex aquifolium were found to be mainly 24-ethylcholesterol, with trace amounts of cholesterol, 24-methylcholesterol and 24-ethyl-5,22-cholestadien-3β-ol. Several pentacyclic triterpenes were partially characterized. 相似文献
3.
Fatty acid composition of roots and root nodules from Alnus species is reported. Differences in total lipid content and in fatty acid composition w 相似文献
4.
A mixture of C27, C28 and C29 sterols was isolated from the lichen Pseudevernia furfuracea and characterized by means of GLC and MS. Mono-, di- and tri-unsaturated sterols were identified as well as a small amount of fully saturated sterols (stanols). Only a part of the total sterols present in the lichen tissue was easily extractable with organic solvents. Another portion was only obtained after saponification of the lichen residue remaining after extraction with organic solvents. The composition of these two fractions difrered considerably, the former contained predominantly 5a,8a-epidioxy-5a-ergosta-6,22-dien-3β-ol (ergosterol peroxide) and 24-ethylcholesta-5,22-dien-3β-ol while in the latter 24-ethylcholesta-5,22-dien- 3β-ol and C28 triene sterols were the main components. 相似文献
5.
The composition of the sterols, sterol esters and fatty acids has been determined in 8-, 11- and 14-day cultures of three members of the Xanthophyceae, Botrydium granulatum, Tribonema aequale and Monodus subterraneus. The main sterols, whether esterified or unesterified, were cholesterol and clionasterol, whose proportions do not vary with age of culture. Much smaller quantities of cycloartenol and 24-methylenecycloartanol were also found in all three algae. The C16 fatty acids are the most common fatty acids in all three algae with C16:1 being particularly abundant. B. granulatum and T. aequale, however, differ from M. subterraneus in having polyunsaturated C16 fatty acids and a smaller proportion of C20:5. 相似文献
6.
Salam Abdou Kabore Georges Combaut Jean-Pierre Vidal Louis Codomier Jean Passet Jean-Pierre Girard Jean-Claude Rossi 《Phytochemistry》1983,22(5):1239-1240
The Mediterranean red alga Rissoella verruculosa contains desmosterol in the esterified form whereas this sterol is not present in the free state. 相似文献
7.
Vicia faba root ribonucleases are bound to Cibacron blue F3GA. A Blue dextran-Sepharose column was used to purify RNase A3, the more abundant enzyme from V. faba root. Using dinucleoside monophosphate as substrates, it appears that this enzyme behaves as a cyclizing phosphotransferase. With high enzyme/substrate ratios on prolonged digestion a partial release of a nucleoside 3′ phosphate occurs. The specificity is relatively high since only the purine-purine phosphodiester linkages out of 16 types of possible links are easily cleaved. When a pyrimidine is involved in the phosphodiester bond, a much slower rate of attack (Py in 5′) or no attack (Py in 3′) was detected. 相似文献
8.
The mycobiont, Xanthoria parietina, and the phycobiont, Trebouxia decolorans, of the lichen X. parietina have been cultured separately and their sterols analysed. X. parietina contained ergosterol and lichesterol as the major constituents together with lower levels of three other C28 sterols. Culture of the mycobiont in the presence of [CD3]-methionine resulted in the incorporation of two deuterium atoms into the C-24 methyl group of these sterols demonstrating that a 24-methylene intermediate was produced as occurs in other fungi. The phycobiont, T. decolorans contained predominantly poriferasterol with lower levels of clionasterol, ergost-5-en-3β-ol, brassicasterol and cholesterol. Two other Trebouxia spp. (213/3 and 219/2) contained similar sterol mixtures. 相似文献
9.
The fate of hydroquinone and catechol administered to a variety of higher plants over a period of several days has been investigated. All plants yielded monoglucosides, while a small number also yielded the gentiobiosides. Fifteen of 23 species examined yielded a phenolic glucoside derivative which appeared to be identical to a compound described earlier by Pridham and Saltmarsh as a phenolic glucoside-6′-sulfate. Definitive chemical synthesis of arbutin-6′-sulfate was achieved and direct comparison with the natural derivative clearly excluded the possibility of a sulfated derivative. 相似文献
10.
The main pathway of ammonia assimilation in the root nodules of Trigonella foenum-graecum is via nodule cytosol glutamine synthetase-glutamate synthase. 相似文献
11.
Partial purification and characterization of NADH-glutamate synthase from faba bean (Vicia faba) root nodules 总被引:1,自引:0,他引:1
Maria del Pilar Cordovilla Josefa Prez Francisco Ligero Carmen Lluch Victoriano Valpuesta 《Plant science》2000,150(2):121-128
The NADH-dependent glutamate synthase (EC 1.4.1.14) from the plant fraction of N2-fixing faba bean (Vicia faba) nodules has been purified 74-fold to a specific activity of about 3 μmol min−1 mg protein−1 with a final yield of 32%. The NADH-GOGAT activity was associated with a single form of the enzyme that behaved as a monomeric protein with a subunit molecular weight of 195 kDa and a native molecular weight from 222 to 236 kDa estimated by gel filtration or PAGE, respectively. The NADH-GOGAT band on SDS-PAGE was cut out and used to produce antibodies. Western blots of SDS-PAGE of crude nodule proteins revealed a 195 kDa polypeptide in root extracts but not in those of leaves or bacteroids. The antiserum also cross-reacted with a polypeptide of camparable molecular weight (195 kDa) from both amide and ureide transporting species legume nodules, indicating that some antigenic epitopes have been conserved between nodule NADH-GOGAT of different species. 相似文献
12.
The sterol composition of the warm-water brown alga Sargassum fluitans Børgesen of the Gulf of Mexico was determined by TLC, GLC and IR measurements. The presence of over ten sterols was suggested, of which four (fucosterol, cholesterol, 24-methylenecholesterol, and trans- 22-dehydrocholesterol) were identified and four (a 24-methylcholesterol, a 24-ethylcholesterol, a 24-methyl-trans-22-dehydrocholestero 1 and a 24-ethyl-trans-22-dehydrocholesterol) were recognized but not definitively identified. Saringosterol and 24-ketocholesterol were not found. The crude sterol mixture from S. fluitans was oxidized by osmium tetroxide to 24-ketocholesterol in poor yield. 相似文献
13.
Under accelerated ageing at high relative humidity and high temperature for 4 days germination and membrane permeability remained unaffected both in sunflower and chick pea seeds. However, the steryl glycoside concentration in the pooled leachate increased progressively with ageing. Total sterols, as well as steryl glycosides and free sterols of the seeds, increased with a concomitant decline in steryl esters under accelerated ageing. Pretreatment with the sterol biosynthesis inhibitor SK & F 7997A3 prevented the increase of total sterols under accelerated ageing conditions but there were increases in the amounts of steryl glycosides and free sterols and a decrease in steryl ester after such treatment, therefore, indicating interconversions of the various sterol types. Accelerated ageing also caused increases in free amino acids and soluble carbohydrate. Low relative humidity-high temperature and high relative humidity-low temperature failed to produce such effects. 相似文献
14.
Sterols were extracted from the lichens Lobaria pulmonaria, Lobaria scrobiculata and Usnea longissima with chloroform-methanol (2:1) (solvent-extractable fraction) followed by saponification of the residual lichen material to give a tightly-bound sterol fraction. The compounds were principally ergosterol, episterol, fecosterol and lichesterol with minor quantities of C17, C28 and C29 monoenes and dienes of the phytosterol type. 相似文献
15.
Unialgal clonal cultures of the diatom Stauroneis amphioxys Gregory, isolated from sea ice of the Indian Ocean sector ofthe Southern Ocean, were grown at 3° and 20°. The relative abundances offatty acids, sterols and phytol for the two cultures are comparable. The two sterols observed [24-methylcholesta-5,22E-dien-3β-ol (79%) and cholesterol (21%)] did not vary with culture temperature. The-major fatty acid composition is typical ofmost diatoms. A pronounced change of ratio with temperature occurred with the pair 16:4 Δ6, 9, 12, 15 and 16:3 Δ6, 9, 12 followed by 18:4 Δ6, 9, 12, 15:18:3 Δ9,12,15 and 20:5 Δ5,8,11,14,17:20:4 Δ8,11,14,17; thus the relative abundances of 16:4, 18:4, 20:5 and 22:6 increase at the lower growth temperature. The total amounts of unsaturated acids do not change with temperature suggesting an effect on the final desaturase step. No cryoprotective role for such changes in lipid composition was inferred. 相似文献
16.
Nine sterols, most showing Δ5- or Δ5,22-unsaturation, were identified in the marine diatom Biddulphia sinensis. One sterol, cholesta-5,22E-dien-3β-ol, comprised 70–80% of the total sterols which is the first such predominance noted in a diatom. The only Δ7-sterol detected was cholest-7-en-3β-ol and this was a very minor component. A sterol showing unusual side-chain alkylation,23,24-dimethylcholesta-5,22E-dien-3β-ol, was identified for the first time in a diatom. Total fatty acids exhibited a predominance of Δ9- 16:1, 14:0, 20:5 and 16:0, typical of diatoms, although the proportions of these acids were found to vary with culture maturity. n-Heneicosahexaene was the major hydrocarbon together with a small amount of squalene. 相似文献
17.
18.
Stigmasta-7,E-24(28)-dien 3β-ol was isolated from the roots of Bryonia dioica; it has been previously synthesised, but never found in the plant kingdom. The stereochemistry of the 24(28) double bond was unambiguously proved by high resolution (250 MHz) 1H NMR. 相似文献
20.