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1.
Besides the known sarmentogenin 3-O--D-allopyranoside (1) and digitoxigenin-3-O-[-D-xylopyranosyl-(14)-2, 3-di-O-acetyl--D-allopyranoside] (4), four new cardiac glycosides (2, 3, 5 and6) have been isolated from the defensive glands of adults ofChrysolina fuliginosa. The structures of the new compounds were determined by1H NMR at 600 MHz and FABMS. Compounds1–6, present in the adults ofC. fuliginosa, have also been identified in the eggs.  相似文献   

2.
Summary 2, 4-dichlorophenol (DCP), 2, 4-dinitrophenol (DNP) and 2, 4-dinitro-o-cresol (DNC) applied at a concentration of 1.10–7 to 1.10–3 M, produce a dramatic increase in IAA-oxidase activity in young cells ofLens root. IAA destruction by breis from root tissues was inhibited by Mn++ ion at low concentrations of DCP (1·10 to 1.10–7 M), but was enhanced by Mn++ ion at higher (1.10–5 to 1.10–3 M) DCP levels.

Ce travail a pu être entreprise grâce à l'appui duFonds national suisse pour la Recherche scientifique.  相似文献   

3.
Zur Stereochemie der Propandioldehydrase-Reaktion   总被引:2,自引:0,他引:2  
Summary Propanedioldehydrase is shown to convert both (+)-(S)-2-2H-propanediol,3, and (–)-(R)-1-2H2-propanediol,5, to specimens of deuterated propion-aldehyde, for which the (S)-configuration has been established. Thus, in the propanedioldehydrase reaction migration of hydrogen atoms from C–1 to C–2 always occurs with inversion of configuration.  相似文献   

4.
Zusammenfassung Es wird gezeigt, dass 3–5-cAMP (10–3 M) und Theophyllin (10–4 M) die Permeabilität derjenigen Lysosmen-Membranen steigern, die aus Rattenleberzellen in bezug auf saure Phosphatase and in bezug auf -Glucuronidase-Enzyme präpariert wurden.  相似文献   

5.
    
Zusammenfassung Die Wirkung von Succinylcholin auf die-Fasern an unanästhesierten spinalen Katzen wurde analysiert: (1) 2–5 antidrome Entladungen einer Frequenz 100–300/sec bei einer elektrischen Einzelreizung; (2) antidrome, repetierende Entladungen ohne elektrische Reizung; (3) Blockierung der-Impulse folgte während 5–15 min den antidromen Entladungen.  相似文献   

6.
Summary The time course of ATPase activity and force has been determined during contraction and relaxation in skinned (hyperpermeable) anterior byssus retractor muscle, ABRM, ofMytilus edulis and compared with corresponding measurements on skinned taenia coli of guinea-pigs. Following a calcium-induced contraction, lowering the [Ca++] to 10–8 M rapidly reduces ATPase activity within 2 min to resting levels while force declines only to about 30–50% of maximal tension within the same time. Thus slow relaxation is due to a catch-like-state which is common to different kinds of smooth muscles and can be reduced with cAMP in ABRM and by Pi in taenia coli.The support by the Deutsche Forschungsgemeinschaft and the excellent technical assistance of Mrs K. Winnikes are gratefully acknowledged.  相似文献   

7.
Summary From the roots ofCroton flavens L., 3 highly irritant and tumor promoting Croton factorsF 1F 3 and the corresponding 3 cryptic Croton factorsF1F3 were isolated and characterized as novel esters of 16-hydroxy- and 4-deoxy-16-hydroxyphorbol, respectively. These findings suggest that tumor promoters of the phorbol ester type, ingested through the widespread and frequent use ofCroton flavens according to local habits, may be causally related to the well recognized high rate of esophageal cancer on Curaçao.Dedicated to Prof. Dr H. P. Rusch, Director Wisconsin Clinical Cancer Center, Madison, Wis. USA, on occasion of his 70th birthday. We wish to thank Dr J.F. Morton, Morton Collectanea, University of Miami, Florida, USA, for kindly supplying us with the plant material.  相似文献   

8.
Summary After application of 3-H uridine to one eye-ball, an intraaxonal flow of RNA (1–3 mm/d) and low-molecular uridine-compounds (30–50 mm/d) has been demonstrated in the optic tract ofScardinius erythrophtalmus andCarassius carassius (Teleostei).  相似文献   

9.
Summary The male antifertility agent 1-amino-3-chloropropan-2-ol (ACP,I) has been shown to be metabolized to-chlorohydrin (III) and metabolites of-chlorohydrin. This accounts for the similar antifertility and renal toxicity effects of both compounds.  相似文献   

10.
Summary Three nitrogenous sesquiterpenoids (4–6), possessing an isocyanide, isothiocyanate or formylamino function, have been isolated from the marine spongeAxinella cannabina. The proposed structures were based on interpretation of spectral data including 2D-NMR techniques and chemical evidence. A plausible pathway for the biogenesis of these compounds and the co-occurring spiro-axane (1–3) metabolites is proposed.Work supported by C.N.R. (Progetto Finalizzato Chimica Fine e Secondaria and by MPI Italy.  相似文献   

11.
Summary Five unusual amino acids were identified as antimutagens against spontaneous mutation ofSalmonella typhimurium TA100: L-azetidine-2-carboxylic acid (1) from Liliaceae plants, -(methylenecyclopropyl)glycine (2) fromLitchi chinensis seeds, and 2-amino-4-methylhex-5-ynoic acid (3), hypoglycin A (4), and (2S, 4R)-2-amino-4-hydroxyhept-6-ynoic acid (5) fromEuphoria longana seeds. The absolute stereochemistry of5 was determined by its chiral synthesis from L-allylglycine, proving that5 is the C-4 epimer of the amino acid previously isolated from dried longan seeds.This work was partly supported by a Grant-in-Aid form the Ministry of Education, Science, and Culture, Japan, No. 57740283 (to HK).  相似文献   

12.
Summary In vitro the decarboxylation ofl-3,4-dihydroxyphenylalanine (DOPA) by total homogenate of rat liver and brain was markedly inhibited by 2.5 × 10–3 M 3,4-dihydroxyphenylpyruvate, although the latter itself appeared to be aminated to a marked extent. In the homogenate or supernatant of various rat tissues, the decarboxylation of DOPA was not significantly affected by the simultaneous course of the DOPA--ketoglutarate-transamination.  相似文献   

13.
Summary In cats pretreated with reserpine, the action of tyramine on the blood pressure is markedly enhanced 30–90 min after infusion of 500 mgl--methyl-dopa, but not after the same amount of the dextro isomer. In normal catsl--methyl-dopa has no influence on this action of tyramine. 1–2 h after the infusion of-methyl-dopa, an increase of the response to tyramine could also be observed in experiments on the nictating membrane of reserpine pretreated cats. The effects of preganglionic electrical stimulation of the cervical sympathetic nerve remained unchanged.  相似文献   

14.
Summary The incorporation of leucice-14C into protein in bovine mesenteric arteries was augmented by cyclic GMP (10–3 M) and decreased by cyclic AMP (10–3 M). There was no effect of 5 AMP (10–3 M). The phosphodiesterase inhibiting drugs theophylline (10–3 M) and papaverine (5×10–5 g/ml) both decreased the leucine-14C incorporation.We are indebted to Mrs.Lena Burlin for hear assistance. Finacial support has been provided by the Swedish State Medical Research Council (No. 04X-101X-4498).  相似文献   

15.
Summary Two new cytotoxic norditerpene dilactones, milanjilactones A(3) and B(4) have been isolated from the stem bark ofPodocarpus milanjianus Rendle and characterized, on the basis of spectroscopic evidence, as 1,2-dehydro derivatives of nagilactones F(1) and G(2).The authors acknowledge the technical assistance of Ms Teresa K. Lightner. Part 11 in the series Potential Antitumor Agents.  相似文献   

16.
Summary The synthesis of the antibiotic novobiocin is described. First the essential carbohydrate, the 3-O-carbamoylnoviose was synthesized fromd-glucose. A number of steps (1–6) led to the 3,5,6-tri-O-benzyl-2-O-methyl-d-galactono--lactone (6) which is characterized by the correct array of carbon atoms inherent to the noviose. Further transformations (7–15) finally yielded the carbohydrate. The problem of glycosidation is discussed in some detail. Glycosidation of a suitable aglycon precursor (18) with 2,3-O-carbonyl--noviosyl-chloride (22) proved possible and led to the isolation of an-glycoside (23) which was further transformed (24–28) into novobiocin.

Chemische Forschungsabteilung der F. Hoffmann-La Roche & Co. AG, Basel.

Vortrag Dr.B. P. Vaterlaus, gehalten an der Gordon Research Conference on Steroids and other Natural Products, 16.–20. Juli 1962, New Hampton, N.H., USA, und vor der Basler Chemischen Gesellschaft, 8. November 1962. Im Auszug:H. Spiegelberg,Synthèse du 3-O-carbamoylnoviose, sucre de la novobiocine, Symposium international de chimie organique, Bruxelles, 15. Juni 1962;J. Kiss,The Synthesis of Noviose and Allied Compounds, Birkbeck College (Univ. London), 23. Oktober 1962. Der vorliegende Aufsatz ist Gegenstand von Detailpublikationen in den Helv. chim. Acta, in Vorbereitung (1963).  相似文献   

17.
Summary The anthocyanidin investigated here exists below pH 4 as a cationAH 2 + (wave length of absorption maximum max=459 mµ), between pH 5 and 7 in the neutral formAH ( max=492 mµ) and above pH 8 as an anionA ( max=537 mµ). At pH 5 the freshly dissolved substance is partially converted into a colourless formBH ( max=372 mµ) and a chemical equilibrium betweenAH andBH is reached within 1 h. A kinetic study of the process of formation ofBH shows that an intermediate productZ is formed. This process can be reversed by light exposure. It can be concluded from a kinetic investigation by using flash light thatBH is transformed by the absorbing light into a new substanceL ( max 275 mµ and 225 mµ), andL changes partially intoBH, partially intoZ, which itself is transformed partially intoAH 2 + ,AH,A , partially intoBH. The reactionZ AH,AH 2 + ,A is proportional to the concentration of protons [H +], the reactionZ BH independent of [H +]. Thus a photochemical production ofAH 2 + ,AH,A fromBH is readily obtained in the presence ofH + and not obtained in the absence ofH +.  相似文献   

18.
Résumé On a extrait de l'écorce des racines deVoacanga chalotiana un nouvel alcalode indolique, la décarbométhoxyapocuanzine. L'étude de son spectre de RMN et la corrélation chimique avec la cuanzine (2) permettent d'attribuer à cet alcalode la structure1.
Riassunto Dalla corteccia della radice dellaVoacanga chalotiana ê stata isolata la decarbometossi apocuanzina (1), un nuovo alcaloide indolico la cui struttura è stata definita per via spettroscopica e mediante correlazione chimica con la cuanzina (2).
  相似文献   

19.
Zusammenfassung Injektionen von Schafprolaktin (0.05–0.10 IE/g Körpergewicht) lösen bei unreifen weiblichen Buntbarschen der ArtAequidens pulcher innerhalb von 2–3 Tagen eine starke Erhöhung der Aktivität der 3-ol-Steroiddehydrogenase in den Ovarien aus. Dies deutet darauf hin, dass auch bei Fischen LtH oder ein ähnliches Hormon in die Regulation des Gonadensteroidstoffwechsels eingreift.  相似文献   

20.
Summary Experiments on influencing cotyledon formation in embryos ofEranthis hiemalis are reported. By treating the seeds with 100–2000 ppm solutions of 2,4-dichlorophenoxyacetic acid, 2,4,5-trichlorophenoxyacetic acid, 2-methyl-4-chlorophenoxyacetic acid, -naphthylacetic acid and even isopropyl N-phenyl carbamate one can obtain significant increases in twinning and in cotyledon anomalies (syncotyly and pleiocotyly of all degrees). Embryos can be successfully treated until approximately 2 weeks after initial opening of the follicles. X-radiations achieve the same effect, with doses of 2000–4000r corresponding to the treatments with 1000–2000 ppm 2,4-D-solutions. By using weaker concentrations and with sudden temperature changes one can likewise raise the percentage of syn-, tri- and tetracotyls, but pleiocotyls of the higher degrees (5 and more cotyledons) appear only when more intensive methods of treatment are employed. These forms which exceed the normal range of variability arise as bud-like embryo regenerates on the as yet undifferentiated original embryo.  相似文献   

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