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1.
Résumé Le 3, 17, 21-trihydroxy 5-pregnane (allo-tétrahydro-17-hydroxy-cortexone) et le 3,21-dihydroxy 5-prégane (allo-tétrahydro-cortexone) ont été identifiés dans l'urine humaine. Ces composés avaient les mêmes migrations chromatographiques avant ou après acétylation ou oxydation que les respectifs stéroïdes de synthèse.  相似文献   

2.
Summary The structures of 2 new polyhydroxylated cannabinoids, (±)9, 10-dihydroxy- 6a(10a)-tetrahydorcannabinol and (±)8, 9-dihydroxy- 6a(10a)-tetrahydrocannabinol, obtained from a hexane extract of an IndianCannabis variant were determined by spectral means and correlation with cannabinol.Acknowledgments. Supported by contract No. HSM-42-70-109 from the National Institute on Drug Abuse and the Research Institute of Pharmaceutical Sciences, School of Pharmacy, University of Mississippi. The authors are grateful to Mrs Glenda Lewis (Research Institute) for running the gas chromatographic analyses and to Mr C. Versluis (Analytical Chemistry Laboratory, University Of Utrecht, The Netherlands) for recording an element list of both compounds.Cannabis Herbarium specimens are stored in the herbarium, Department of Pharmacology, School of Pharmacy, University of Mississippi, University, MS 38677, USA.  相似文献   

3.
The isolation of N-quinaldyl-L-arginine·HCl (1) from the CoccinellidaeSubcoccinella-24-punctata is reported. The structure, first established on the basis of the analysis of the spectral properties of1, has been confirmed by synthesis. The alkaloid is of endogenous origin and markedly deterrent to ants.  相似文献   

4.
Summary Chemistry, salidiuretic activity and mechanism of action of 3-amino-1-(3,4-dichloro--methyl-benzyl)-2-pyrazolin-5-one (Bay g 2821), a new diuretic, are described. Owing to the initial rapid onset of activity, the reserve in capacity and the additional long duration of activity, this substance represents a potent diuretic and antihypertensive agent.  相似文献   

5.
Summary Synthesis and preliminary biological activity of (–)cis-2(-dimethylamino-m-hydroxybenzyl)cyclohexanol, a novel analgesic agent is described.  相似文献   

6.
修正的Kleene系统中的Σ-(α-重言式)理论   总被引:12,自引:1,他引:11  
证明了关于全体赋值而言 ,修正的Kleene系统中只有 3种α 重言式 .在赋值域为有限集的情形证明了当α过半时α 重言式的类类互异定理 .最后 ,在有限值系统中证明了广义重言式的重言式表示定理 .  相似文献   

7.
Résumé Le sang des femmes enceintes peut contenir plusierus protéines sériques uniques en leur genre. Celle qui se présente le plus souvent est une -globuline de grand poids moléculaire. Un test in vitro utilisant l'incorporation de14C-glutamine ou3H-leucine dans la glycoprotéine a montré que celle-ci peut être synthétisée par des leucocytes.

We thank Dr.J. E. O'Grady and Dr.A. Shephard for obtaining the blood samples. This work was supported by a grant from the Scottish Home and Health Department.  相似文献   

8.
Summary A novel sesquiterpene lactone, 9--hydroxyparthenolide (1) was isolated from a chloroform extract ofAnvillea garcini that was collected in Iran. The structure of1 was assigned on the basis of high field NMR decoupling experiments and other spectroscopic evidence. This -methylene lactone has shown significant activity in both the 9KB cell culture and P388 mouse leukemia test systems.The authors acknowledge the support of contract No. N01-CM-97296 from the National Cancer Institute and the use of the Purdue University Biochemical Magnetic Resonance Laboratory (NIH grant No. RR01077). This is paper 16 in the series Potential Antitumor Agents.  相似文献   

9.
Summary The cells of heterogametic females with ZW sex chromosomes express H-Y or H-W antigen. A hypothesis is formulated to explain why these animals are capable of practicingamphigonia retardata, i.e. delay in actual fertilization of eggs by retaining viable sperm within the oviduct for a considerable time (several months).  相似文献   

10.
11.
Summary On treatment of 3-hydroxy-5-steroids with lead tetra-acetate formation of 3, 9-oxides is observed. The yields of this ring closure reaction decrease significantly in the order 11-keto, 9, 11-ene and ring-C saturated compounds.  相似文献   

12.
13.
Summary In the European dimorphic ant,Pheidole pallidula, the Dufour's gland of the major workers is hypertrophied and secretes nearly pure (Z, E)--farnesene. This compound is also present in the Dufour's gland of the minor workers but constitutes only around 10% of the volatiles. Chemical polymorphism inP. pallidula is different from that already reported for species ofPheidole from the New World.Aspirante au Fonds National de la Recherche Scientifique.Maître de recherches du Fonds National de la Recherche Scientifique.  相似文献   

14.
苯并(a)芘的环境污染、健康危害及研究热点问题   总被引:30,自引:0,他引:30  
本文主要介绍了多环芳烃类中致癌性最强的化合物之一-苯并(a)芘对人体健康的危害,污染来源和程度,环境质量和污染排放标准,以及目前的科研热点问题。  相似文献   

15.
Insulin action is initiated by binding to its cognate receptor, which then triggers multiple cellular responses by activating different signaling pathways. There is evidence that insulin receptor signaling may involve G protein activation in different target cells. We have studied the activation of G proteins in rat hepatoma (HTC) cells. We found that insulin stimulated binding of guanosine 5′-O-(3-thiotriphosphate) (GTP-γ-35S) to plasma membrane proteins of HTC cells, in a dose-dependent manner. This effect was completely blocked by pertussis toxin treatment of the membranes, suggesting the involvement of G proteins of the Gα i/Gα o family. The expression of these Gα proteins was checked by Western blotting. Next, we used blocking antibodies to sort out the specific Gα protein activated by insulin stimulation. Anti-Gα il,2 antibodies completely prevented insulin-stimulated GTP binding, whereas anti-Gα o,i3 did not modify this effect of insulin on GTP binding. Moreover, we found physical association of the insulin receptor with Gα i1,2 by copurification studies. These results further support the involvement of a pertussis toxin-sensitive G protein in insulin receptor signaling and provides some evidence of specific association and activation of Gα i1,2 protein by insulin. These findings suggest that Gα i1,2 proteins might be involved in insulin action. Received 23 September 1998; received after revision 23 November 1998; accepted 25 November 1998  相似文献   

16.
Summary A -glucosidase (linamarase) was purified 52-fold with a recovery of 27% from the haemolymph of the larvae ofZygaena trifolii, ESPER, 1783 (Lepidoptera, Zygaenidae). The final enzyme preparation was found to be nearly homogeneous on both disc polyacrylamide gel electrophoresis and SDS-polyacrylamide gel electrophoresis. The molecular weight of the enzyme was determined to be about 130 kDa; it consisted of two subunits of about 66 kDa. The enzyme showed an optimum between pH 4.5 and 5 with linamarin and a broad optimum between pH 3.5 and 6.5 for p-nitrophenyl--D-glucoside; the temperature optimum was 40°C. The -glucosidase showed a high specificity for its endogenous substrates linamarin and lotaustralin. Among the other natural and artificial substrates tested, only prunasin and p-nitrophenyl--D-glucoside were hydrolyzed by the enzyme, whereas linustatin, salicin, cellobiose and trehalose were not. The enzyme is strongly inhibited by -glucosylpiperidine.  相似文献   

17.
18.
Zusammenfassung Paraoxon beeinflusst die Wirkung von-Lobelin über den Axonreflex, der Schwitzen menschlicher Haut auslöst. Geringe Konzentrationen von-Lobelin werden durch Paraoxon verstärkt, während höhere gehemmt werden. Daraus wird gefolgert, dass endogenes Acetylcholin an der Auslösung des Axonreflexes beteiligt sein kann.  相似文献   

19.
F V DeFeudis 《Experientia》1978,34(10):1314-1315
Bicuculline- and strychnine-sensitive components of the binding of GABA, glycine and beta-alanine, which can be demonstrated in the presence of a physiological concentration of Na+, might be related to synaptic receptors.  相似文献   

20.
Summary A new sesquiterpene alcohol, 12-hydroxy-E--bisabolene, is reported from an undescribed Caribbean sea whip of the genusPseudopterogorgia. The structure of this new alcohol was established based upon spectral analyses and through chemical interconversions.Acknowledgment. This research was supported by NOAA, Office of Sea Grant, Department of Commerce, under grant NA80AA-D-00120, and in part by the California State Resources Agency, project R/MP-22. The U.S. Government is authorized to reproduce and distribute reprints. We wish to acknowledge the mass spectral support provided by the Bioorganic Biomedical Mass Spectrometry Resource Center, University of California, San Francisco (A.L. Burlingame, Director) which is supported through NIH grant RR00719.  相似文献   

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