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101.
Effects of fasting on hepatic catecholamine receptors 总被引:1,自引:0,他引:1
102.
103.
Core particle DNA unfolding and refolding are followed by stopped-flow circular dichroism technique. When core particles are dissociated in the stopped-flow cuvette, the high CD deviation corresponding to the dissociated state is reached in the first millisecond, which means that the dissociation process is completed within the dead time of the apparatus which is ~1 ms. The same conclusion can be drawn when core particles are reassociated, since the low CD value, typical of the associated state, is immediately reached. Similarly histone release from chromatin is a very fast process. We also include some points of discussion about core particle assembly process. 相似文献
104.
J C Zolman 《FEBS letters》1982,143(1):26-28
Aspartate, glutamate, serine and glycine all permeate the inner membrane of mitochondria isolated from both etiolated and green plant tissues. No significant difference was found in the transport characteristics shown by mitochondria from either tissue. Influx of each amino acid appears diffusional because substrate saturation was not observed and there was no indication of specific inhibition or a requirement for a compensatory or counter ion for uptake. In contrast, uptake of the keto acid pyruvate did appear saturable. Inhibition by α-cyano-4-hydroxycinnamate, mersalyl and FCCP, but not valinomycin, suggests a carrier and a ΔpH mediate pyruvate transport into the matrix. 相似文献
105.
External application of estradiol-17β increased shoot growth but decreased root growth of sunflower seedlings. It completely inhibited cotyledonary axillary bud development in decapitated plants at the concentration of 1 μg/plant. Concentrations lower than this promoted cotyledonary axillary bud formation. Testosterone on the other hand inhibited both shoot and root growth and promoted cotyledonary axillary bud formation at all the concentrations used. Progesterone at high (0.25,μg/plant) concentration promoted shoot growth but inhibited root growth. A low concentration (0.1 μg/plant) of progesterone produced the opposite effect. 相似文献
106.
Twenty-seven mainly terpenoid constituents were identified in the essential oil of Mikania micrantha whole plant. Higher terpenoids present in the same plant included two kaurene derivatives and taraxasterol. 相似文献
107.
Sterols were isolated from ten mushrooms, Hygrocybe punicea, Lampteromyces japonicus, Leucopaxillus giganteus, Lentinus edodes, Flammulina velutipes, Amanita caesarea, Coprinus atramentarius, Russula foetens, R. nigricans and R. senecis. The compositions of the sterol fractions were determined by GLC, combined GC/MS, and 1H NMR. Ergosterol was present in all the mushrooms. Other sterols found were 5α-cholest-7-en-3β-ol and ergosta-5,7-dien-3β-ol. Ergosta-5,8,22-trien-3β-ol was isolated from F. velutipes. 相似文献
108.
The β-carbon of the acyl group of β-hydroxy-β-methylglutarylhydroxyabscisic acid was shown to possess R-configuration by HPLC analysis of the reduced product. 相似文献
109.
The structures of two 4α-methylsterols is isolated from Cucumis sativus(Cucurbitaceae) seeds were determined based mainly on their 13CNMR spectra as 24β-ethyl-31-norlanosta-8,25(27)-dien-3β-ol and 24β-ethyl-25(27)- dehydrolophenol, respectively, of which the former is a new sterol from natural sources. These two 4α-methylsterols were identified in the seeds of two other Cucurbitaceae species, Lagenaria leucantha var. Gourda and Citrullus battich. The probable biogenetic significance of the two 4α-methylsterols is discussed. Other 4α-methylsterols identified in the seeds of the three Cucurbitaceae species were obtusifoliol, cycloeucalenol and gramisterol. 相似文献
110.
Simon E. Moroney Kathlyn J. Ronaldson Alistair L. Wilkins T.G.Allan Green P.W. James 《Phytochemistry》1981,20(4):787-789
A new lichen depsidone was isolated, in the form of its triacetate derivative from the acetylated extracts of Nephroma antarcticum and has been demonstrated to be hypoconstictic acid-triacetate. Two related depsidones, hypostictic acid hyposalazinic acid, were isolated from N. australe. 相似文献