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61.
One new and five known compounds, which all showed cytotoxic activity, were isolated from the rhizomes of Zingiber zerumbet. The new compound was 3″,4″-O-diacetylafzelin. The known compounds were zerumbone, zerumbone epoxide, diferuloylmethane, feruloyl-p-coumaroylmethane and di-p-coumaroylmethane. Several substituted cinnamoylmethanes were synthesized and tested for cytotoxic properties. Among these were tricinnamoylmethane and triferuloylmethane. The structures were elucidated mainly by spectroscopic methods and 13C NMR data are given. 相似文献
62.
A Van Dorsselaer R Nebhi O Sorokine P Schindler B Luu 《Comptes rendus de l'Académie des sciences. Série III, Sciences de la vie》1987,305(14):555-560
By studying highly purified CNS proteolipids, we have shown that DM-20 proteolipid, which was considered, until now, to be a minor brain proteolipid is, in fact, almost as abundant as the Major Myelin Proteolipid known also as Proteolipid Protein (PLP). DM-20 proteolipid is even the major brain proteolipid in young foetuses. It is only during myelinisation that the "Proteolipid Protein" increases rapidly and becomes equivalent in weight to DM-20 proteolipid. This study raises the question of the particular function of DM-20 proteolipid. 相似文献
63.
L Richert M Castagna J P Beck S Rong B Luu G Ourisson 《Biochemical and biophysical research communications》1984,120(1):192-198
Creatine kinase (CK) activity in plasma obtained non-invasively from adult healthy, Sprague-Dawley, male rats was found to be 528 +/- 270 U/L (N = 17), a value which was 7 times that obtained in human specimens. Agarose gel electrophoresis revealed that the only detectable CK isoenzyme present was CK-BB, in contrast to the human serum isoenzyme which was CK-MM. Furthermore, it was found that the rat CK-BB could be detected using an RIA technique designed to quantitate human CK-BB occasionally present in blood after brain injury (rat CK-BB = 84.5 +/- 55.2 micrograms/L, N = 17, human CK-BB: Not detectable). It was thus possible to calculate the CK-BB specific activity (SA) in rat plasma using total CK assay and RIA (rat CK-BB SA = 6.25 +/- 3.87 U/micrograms, N = 17). When six rats (156 +/- 23 g) were treated with lead acetate in the drinking water (26 mM) for 3 weeks, the CK-BB SA rose to 18 +/- 5.8 U/micrograms (P less than .02). At this point the electrophoresis pattern of the CK-BB showed a transient change from a single band to a doublet. The dose was then increased to 52 mM for 6 weeks, during which time the CK-BB SA declined steadily to 1.6 +/- 0.6, a level significantly less than that of the untreated animals (p less than .02). The results suggest that chronic lead treatment evokes a biphasic response in CK-BB SA with the initial release of enzyme of high SA from tissues. Further treatment apparently results in an inactivation of the enzyme within lead sensitive tissues. 相似文献
64.
V. A. Andryushina N. V. Rodina T. S. Stytsenko Luu Duc Huy A. V. Druzhinina V. V. Yaderetz N. E. Voishvillo 《Applied Biochemistry and Microbiology》2011,47(3):270-273
Soybean sterols were converted into androst-4-ene-3,17-dione (AD) and 9α-hydroxyandrost-4-ene-3,17-dione (9-OH-AD) using three actinobacterium strains. The transformation of a microcrystallic substrate (particle size 5–15 μm) or the transformation
in the presence of randomly methylated β-cyclodextrin (MCD) were carried out by Mycobacterium neoaurum with a phytosterol load of 30 g/l over 144 h with an AD content of 14.5 and 15.2 g/l, respectively. AD obtained in the presence
of MCD was transformed into ADD (13.5 g/l) by Pimelobacter simplex cells over 3 h and into 9-OH-AD by Rhodococcus erythropolis cells after 22 h without the isolation of AD from the cultural liquid. The crude product ADD was obtained in 75% yield, based
on phytosterol. It contained as by-products 1.25% of AD and 1.5% of 1,2-dehydrotestosterone. In a control experiment—the process
of 1,2-dehydrogenation of 20 g/l AD in the water solution of MCD—no by-products were isolated. Thus, it is more expedient
to introduce the 1,2-double bond into pure AD, whereas R. erythropolis strain with low destructive activity towards steroid nucleus can be used in the mixed culture with M. neoaurum. The crystal product contained, according to HPLC, 80% of 9-OH-AD, and 1.5% AD was obtained. The yield of 9-OH-AD (m.p. 218–220°C)
based on transformed phytosterol was 56%. 相似文献
65.
66.
The effects of 7 beta-hydroxycholesterol on lymphoma cells in culture, on lymphocytes entering blastic transformation and on quiescent murine spleen lymphocytes have been investigated. The early events of blastogenesis as well as YAC-1, RDM-4 and EL-4 cells were shown to be very sensitive to this sterol at microM concentration, whereas constituted lymphoblasts and normal lymphocytes remained insensitive at 50 times higher concentration. The effect of some classical antitumor drugs (Adriamycin, Mitomycin-C, Methotrexate) on these lymphoma cells were of the same order of magnitude. However, the activity of 7 beta-hydroxycholesterol was closely related to the composition of the culture medium. Indeed, the cytotoxic effects of this compound were less in medium supplemented with foetal calf serum than in lipoprotein poor, Ultroser-G supplemented medium. The possible impairment of the same, or closely related, events occurring in blastic transformation and in rapid proliferation of cells is pointed out. Our results raise the question of the possible use of these compounds for an antitumor strategy. 相似文献
67.
5-hydroxylation of benzimidazole by micromycetes II. Optimisation of production with Absidia spinosa
Françoise Seigle-Murandi Régine Steiman Frédérique Chapelle Cuong Luu Duc 《Applied microbiology and biotechnology》1986,25(1):8-13
Summary The bioconversion of benzimidazole to 5-hydroxybenzimidazole was investigated as a function of the physiological state of the fungus and culture conditions. Using an inoculum composed only of spores, the addition of benzimidazole at different times of development led to a better definition of optimal physiological conditions for obtaining a good hydroxylation yield. The relationship between the degree of hydroxylation and that of culture medium aeration, was shown by the use of four different conditions: flowing medium on an inert support, in static, agitated or highly aerated medium. 相似文献
68.
Ovaries of adult have recently been shown to produce impressive amounts of ecdysone together with low polarity ecdysteroids, some of which cross-react with ecdysone in our RIA. A gas chromatographic-mass spectrometric analysis of extracts from ovaries of has shown the presence of following compounds (less polar than ecdysone): 2-deoxy-ecdysone, 2,22-bis-deoxy-ecdysone, 2, 22, 2 5-tri-deoxy-ecdysone, 2, 14, 22, 2 5-tetra-deoxy-ecdysone. No other related ecdysteroids were present in our extracts. Cholesterol is used by ovaries as a precursor for ecdysone biosynthesis, as our previous studies with labelled products have shown, and we propose that the compounds detected in the present work represent biosynthetic intermediates between cholesterol and ecdysone in ovaries. 相似文献
69.
Full length cDNA structure and deduced amino acid sequence of human 3 beta-hydroxy-5-ene steroid dehydrogenase 总被引:3,自引:0,他引:3
V Luu The Y Lachance C Labrie G Leblanc J L Thomas R C Strickler F Labrie 《Molecular endocrinology (Baltimore, Md.)》1989,3(8):1310-1312
Polyclonal antibodies raised against 3 beta-hydroxysteroid dehydrogenase isolated from human placenta were used to screen a lambda gt11 expression cDNA library from the same tissue. The protein deduced from cDNA sequences contains 372 amino acids with a calculated mol wt of 42,216. Since 3 beta-hydroxysteroid dehydrogenase is the enzyme catalyzing the formation of all classes of hormonal steroids, the availability of the cDNA encoding this enzyme opens new possibilities for a detailed investigation of the factors regulating the expression and activity of this crucial enzyme in adrenal, gonadal as well as peripheral tissues. 相似文献
70.
Small trypanosome RNA-binding proteins TbUBP1 and TbUBP2 influence expression of F-box protein mRNAs in bloodstream trypanosomes 总被引:2,自引:0,他引:2 下载免费PDF全文
Hartmann C Benz C Brems S Ellis L Luu VD Stewart M D'Orso I Busold C Fellenberg K Frasch AC Carrington M Hoheisel J Clayton CE 《Eukaryotic cell》2007,6(11):1964-1978