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1.
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   

2.
    
Summary Solanocapsine has for the first time been degraded to a known steroid, 3-acetoxy-16-hydroxy-5-bis-22, 23-nor-cholanic lactone. According to this and further experimental evidence, solanocapsine is 3-amino-22, 26-imino-16, 23-epoxy-5, 22, 23, 25 -cholestan-23-ol.

Solanum-Alkaloide. XII. Mitteilung. — XI. Mitteilung:K. Schreiber undH. Rönsch, Abh. dtsch. Akad. Wiss., Berlin, Kl. Chem., Geol., Biol. (im Druck).  相似文献   

3.
Zusammenfassung Zerhackte menschliche Hoden und Epididymis wurden mit Dehydroepiandrosteron ohne Kofaktoren bebrütet und es wurden unter anderem 7-und 7-Hydroxydehydroepiandrosteron und 5-Androsten-3, 7, 17-triol charakterisiert. Die Ausbeute an 7-hydroxylierten Metaboliten war fast gleich in Hoden und Epididymis.

The authors wish to thank Mr.J. Novák for his excellent technical assistance. We are indebted to Dr.J. E. Jirásek for generous performance of histological control of tissue and to Dr.S. Röhling for his kind pernission of radioactivity measurements.  相似文献   

4.
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   

5.
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   

6.
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   

7.
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   

8.
Summary The new methods for the production of 19-norsteroids described involve the conversion of 5-halogen-6-hydroxy-steroids into the corresponding 5-halogen-6:19-ethers either with lead tetraacetate or by the hypoiodite reaction8,10. The 6:19-oxygen bridge is then opened reductively either directly or after oxidation of the 6:19-ethers to lactones or preferably after introduction of a 4,6-3-oxo grouping. Acylolytic cleavage of the 4-3-oxo-6:19-ethers followed by alkaline hydrolysis gives 4,6-3-oxo-19-hydroxy-steroids. The 19-hydroxycompounds formed are easily converted into 19-norsteroids by known methods.

Über Steroide, 189. (vorläufige) Mitteilung; 188. Mitt. vgl.J. Kalvoda, J. Schmidlin, G. Anner undA. Wettstein, Exper.18, 398 (1962).  相似文献   

9.
G-protein signaling: back to the future   总被引:14,自引:0,他引:14  
Heterotrimeric G-proteins are intracellular partners of G-protein-coupled receptors (GPCRs). GPCRs act on inactive G·GDP/G heterotrimers to promote GDP release and GTP binding, resulting in liberation of G from G. G·GTP and G target effectors including adenylyl cyclases, phospholipases and ion channels. Signaling is terminated by intrinsic GTPase activity of G and heterotrimer reformation – a cycle accelerated by regulators of G-protein signaling (RGS proteins). Recent studies have identified several unconventional G-protein signaling pathways that diverge from this standard model. Whereas phospholipase C (PLC) is activated by Gq and G, novel PLC isoforms are regulated by both heterotrimeric and Ras-superfamily G-proteins. An Arabidopsis protein has been discovered containing both GPCR and RGS domains within the same protein. Most surprisingly, a receptor-independent G nucleotide cycle that regulates cell division has been delineated in both Caenorhabditis elegans and Drosophila melanogaster. Here, we revisit classical heterotrimeric G-protein signaling and explore these new, non-canonical G-protein signaling pathways.Received 21 October 2004; received after revision 20 November 2004; accepted 30 November 2004  相似文献   

10.
Summary Uptake ofd-glucose anomers by isolated rat retina was studied. After 3 min incubation at 37°C in the presence of or anomer (750 g/ml), a significantly greater uptake (1.32 mg/g wet tissue) of -anomer was observed compared with that of -d-glucose (1.11 mg/g wet tissue). This result and other data suggest that the carrier ford-glucose transport in the retina prefers the -anomer stereospecifically.Acknowledgment. The authors are grateful to Mr S. Suzuki for his technical assistance.  相似文献   

11.
Summary - and -ecdysone were synthesized from labelled cholesterol by premolt crayfish in vivo and by their Y-organs in vitro.  相似文献   

12.
A major cytokinin found in coconut milk was isolted by using the tobacco callus growth-promoting assay as a guide during purification. The structure of the factor was determined to be 14-O-{3-O-[-d-galactopyranosyl-(12)--d--galactopyranosyl-(13)--L-arabinofuranosyl]-4-O-(-L-arabinofuranosyl)--d-galactopyranosyl}-trans-zeatin riboside [G3A2-ZR] by various NMR techniques, including heteronuclear multiple bond connectivity by 2D multiple quantum NMR (HMBC), as well as mass spectroscopy and sugar analysis. The optimum concentration of G3A2-ZR for cytokinin activity in the tobacco callus assay was estimated to be 5×10–6 M, so that G3A2-ZR is one order of magnitude more potent than 1,3-diphenylurea and one order less potent than zeatin riboside. At least 20% of the cytokinin activity of coconut milk could be attributed to G3A2-ZR.  相似文献   

13.
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   

14.
Summary The syntheses and structure-determinations of 1, 22- and 1, 2-methylene-19-nor-17-acetoxy-progesterones described prove that there is no influence of the angular C10-methylgroup on the steric course of theCourey-methylenations of 1-3-keto-steroids.  相似文献   

15.
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   

16.
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   

17.
Summary 26-Hydroxy--ecdysone has been identified as a metabolite of the moulting hormone, -ecdysone inCalliphora erythrocephala.  相似文献   

18.
Summary Synthetic analogue of ecdysone, 3, 14-dihydroxy-5-cholest-7-en-6-one did not bring the scorpionPalamnaeus bengalensis to moult. It also failed completely in stimulating the scorption to produce any change related to moulting.Acknowledgment. Author is grateful to Dr Suresh C. Shrivastava for providing research facilities, Dr S.P. Tewarson for encouragement and S.C.S.T. (U.P.) for funds. Present address: Department of Zoology, Lucknow Christian College, Lucknow-226001.  相似文献   

19.
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   

20.
Summary The steroidal alkaloid solanidine (solanid-5-ene-3-ol, II) which occurs in the potato plantSolanum tuberosum L. has been synthesized from demissidine (5-solanidane-3-ol, I), an alkaloid from the Mexican wild potatoSolanum demissum Lindl. The synthesis involves the following steps: 5-solanidane-3-one, 2,4-dibromo-5-solanidane-3-one, solanid-4-ene-3-one, 3-acetoxy-solanida-3,5-diene, and solanidine (II).

Solanum-Alkaloide. XVII. Mitteilung. — XVI. Mitteilung:K. Schreiber undG. Adam, Exper.17, 490 (1961).  相似文献   

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