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 31 毫秒
1.
Zusammenfassung Die Struktur desp-Brombenzoates des Benzilsäureumlagerungsproduktes von 3, 17-Diacetoxy-11-hydroxy-12-oxo-5-9(11)-androsten wurde durch dreidimensionale Röntgenstrukturanalyse eines Einkristalls als 3-p-Brombenzoat des 11-Carboxy-3, 11, 17-trihydroxy-13-C-nor-5-androstan 11a, 17-Laktons erkannt.  相似文献   

2.
Zusammenfassung Es wird über die Herstellung des 16-Methylprednisons berichtet, welche vom Hecogenin ausgehend über ca. 15 Stufen durchgeführt wird. Als wichtige Zwischenstufe treten 5-Pregn-16-en-3-ol-11, 20-dion-Acetat und 16-Methylen-5-pregnan-3, 17-diol-11, 20-dion auf: letzteres wird durch eine stereospezifische katalytische Reduktion in das entsprechende 16-Methyl-derivat umgewandelt.  相似文献   

3.
Summary Starting from 17-hydroxy-17-hydroxymethyl-4-androsten-3-one, we synthesized 4-chloro-17-hydroxy-17-hydroxymethyl-4-androsten-3-one-17, 20-acetonide and 17-hydroxy-17-hydroxymethyl-1, 4-androstadien-3-one. 11, 17-dihydroxy-17-hydroxymethyl-4-androsten-3-one was obtained from cortisone via methyl-17-hydroxy-3, 11-dioxo-4-etienate.  相似文献   

4.
Summary -Asp1-Angiotensin II had a more pronounced action on the blood pressure of nephrectomized rats than the corresponding-compound.-Asp1-Angiotensins were more slowly destroyed by rat serum, rat kidney homogenate, and human plasma than-compounds, especially-Asp1-Angiotensin II amide.  相似文献   

5.
Defensive steroids from a carrion beetle (Silpha americana)   总被引:2,自引:0,他引:2  
Summary The defensive anal effluent discharged bySilpha americana in response to disturbance contains a mixture of steroids stemming from a glandular annex of the rectum. The compounds have been characterized as 15-hydroxyprogesterone (1, principal component), 5-pregnan-15-ol-3, 20-dione (2), 5-pregnan-3, 15-diol-20-one (3), 5-pregnan-7, 15-diol-3,20-dione (4), 5-pregnan-3, 7, 15-triol-20-one (5), 5-pregnan-16-ol-3,20-dione (6), and 5-pregnan-3, 16-diol-20-one (7), none previously found in insects. Bioassays with jumping spiders showed compounds1 and6 to be feeding deterrents at the 1 g level.Paper No. 78 of the series: Defense Mechanisms of Arthropods. Study supported by NIH (Grants AI-02908, AI-12020). We thank Maura Malarcher and Maria Eisner for excellent technical help, and the Squibb Institute of Medical Research for samples of authentic reference compounds.  相似文献   

6.
Summary The synthesis of 17-hydroxy-17-hydroxymethyl-4-androsten-3-one fromReichsteins compound S is described. Transformation of 3,3-ethylenedioxy-17-hydroxy-17-hydroxymethyl-5-androsten into 17-methyl-isotestosterone demonstrates the configuration of the substituents at C-17.  相似文献   

7.
Summary 3, 16-diacetoxy-5-pregnane-20-one and the analogue pregn-5-ene derivative have been converted into (22R, 25R)-22, 26-imino-5-cholestane-3, 16-diol. The configuration at C-22 and C-25 was determined by transformation into the known (22R, 25R)-5-solanidane-3-one. Application of the Ruschig method led to (25R)-22,26-imino-5-cholest-22(N)-ene-3, 16-diol.

Solanum-Alkaloide. XVI. Mitteilung. — XV. Mitteilung:K. Schreiber undH. Ripperger, Tetrahedron Letters Nr.27, 9 (1960).  相似文献   

8.
Summary Effects of - or -D-glucose on the respiration of germinated spores (only germinated spores not including swollen spores and elongated spores) ofBacillus subtilis andB. megaterium were studied. In our conditions, net amount of oxygen consumed by 1010 germinated spores ofB. subtilis per min after addition of - or -D-glucose was 1.6 g or 6.6 g (/=4.13), while that byB. megaterium was 4.5 g or 6.8 g (/=1.51), respectively. However, the net amounts of oxygen consumed by 1010 vegetative cells per min after addition of - or -D-glucose were identical, forB. subtilis in both cases 443.0 g and forB. megaterium in both cases 604.4 g.  相似文献   

9.
Summary Carbohydrase activity has been demonstrated in homogenates of the alimentary tracts of late instar larvae ofC. maculatus:-D galactosidase, -D glucosidase and N-acetyl-D glucosaminidase activities were comparable and significantly greater than -D galactosidase,-D glucosidase and -D mannosidase. The effects of pH and substrate concentration are reported. The presence and changes in pattern of non-specific esterase activity in larval and adult gut homogenates is also described.  相似文献   

10.
Zusammenfassung Die Bildung von 11-Carboxy-3, 11, 17-trihydroxy-13-C-nor-5-androstan 11a,17-Lakton aus 3, 17-Diacetoxy-11-hydroxy-12-oxo-5-9(11)-androsten wird beschrieben. Der Mechanismus und die Stereochemie dieser Umwandlung (Retro-Aldolkondensation und Benzilsäureumlagerung) wird diskutiert.  相似文献   

11.
Summary Amylase, - and -glucosidase, - and -galactosidase, -fructosidase, trypsin, aminotripeptidase, leucine-aminopeptidase, prolinase, prolidase glycyl-L-leucine dipeptidase and glycylglycine dipeptidase are present in the 3rd instar larvae ofChilo auricilius.Dr Kishan Singh, Indian Institute of Sugarcane Research, Lucknow, is gratefully acknowledged for providing necessary facilities.  相似文献   

12.
Summary The-d-fucosidase and -l-fucosidase activities of digestive juice ofHelix pomatia have been studied.-d-fucosidase can be separated from-d-galactosidase by heat inactivation.  相似文献   

13.
Summary The conversion of cholesterol into 19-nor-5-cholestan-3-ol by the spongeAxinella polypoides involves a partial loss (40%) of the 3-hydrogen atom; moreover administration to the sponge of [4-14C]cholesterol tritiated at C-4 and C-7 showed that the 4- and 7-hydrogen atoms are retained in this conversion. A competitive uptake experiment, [4-14C]cholesterol vs. [7-3H2]5-cholestanol, showed that the sponge utilized exclusively cholesterol for the production of 19-nor-5-cholestan-3-ol.Part of this work has been presented at the Nato Conference on Marine Natural Products (Jersey, Great Britain, October, 1976).-This contribution is part of the Programma finalizzato Oceanografia e Fondi marini-sottoprogetto Risorse biologiche C.N.R. Italy.  相似文献   

14.
Summary InAeshna cyanea larvae, - and -ecdysone stimulate DNA synthesis in the midgut regenerative cells. In last larval instar, the number of cells obtained after the imaginal epithelium genesis is greater after - than after -ecdysone supply. Such a result should be compared with the imaginal epithelium differentiation which occurs earlier after -ecdysone injection.  相似文献   

15.
Zusammenfassung Die Darstellung der beiden epimeren C21-Methylderivate des 9-Fluorprednisolons wird beschrieben. 9-Fluor-21-methyl-1, 4-pregnadien-11, 17, 21B-triol-3, 20-dion-21-azetat ist ein hochwirksames entzündungshemmendes Steroid, vollkommen frei von Nebenwirkungen der Natrium- und Wasserretention des C21-unsubstituierten 9-Fluorprednisolons.  相似文献   

16.
Summary 5- and 5-androstane-17-ol-3-one-17-acetate have been prepared from 5-androstane-6, 17-diol-3-one-17-acetate by a synthesis involving directedHuang-Minlon-reduction.Separation of 5-androstane-17-ol-3-one from its 5-isomer could readily be achieved by crystallisation of their 3-ethylenketals from acetone.  相似文献   

17.
    
Summary The effect of 5-androstan-17-ol-3-one (DHT) and of 5-androstan-3,17-diol (3-diol) on stress-induced prolactin hypersecretion has been investigated in castrated female rats. A 6-day treatment with 2 mg of these steroids does not inhibit the ether-induced increase in prolactin serum levels.  相似文献   

18.
Summary Direct incorporation and cold trap experiments suggest that cholest-4-en-3-one is an intermediate in the conversion of cholesterol into 3-hydroxymethyl-A-nor-cholestane in the marine spongeAxinella verrucosa. Cholest-4-en-3-one is further transformed by the sponge into cholest-4-en-3-ol, 5-cholestan-3-one and 5-cholestan-3-ol; these compounds arise from side reactions, which are not part of the major metabolic route leading to 3-hydroxymethyl-A-norsteranes.  相似文献   

19.
Zusammenfassung Durch Behandlung mit Kalilauge erleidet 5-methyl-19-norcholestan-9, 10-diol-3, 6-dione eine Retroaldolisomerisierung unter Bildung des 10-Hydroxy-Isomers. Letzteres wurde als Hemiketalderivat isoliert. Bei drastischer Behandlung mit Alkali gehen beide Isomere in ein Anthrasteroid über.  相似文献   

20.
Zusammenfassung 4-C14-Testosteron wurde durch Mäuseplazenta in vitro zu Steroiden umgesetzt: 3-Hydroxy-5-androstan-3, 17-dion, 3-Hydroxy-5-androstan-3, 17-dion, 4-Androsten-3, 17-dion und 5-Androstan-3, 17-dion. Eine Umsetzung von Testosteron zu Östrogenen wurde nicht nachgewiesen.  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