9 Diene 3
Mostrando 13-24 de 31 artigos, teses e dissertações.
-
13. Cicloprogramação de 1,3-dienos substituidos pela reação de Simmons-Smith
The cyclopropanation of 1,3-diene by the Simmons-Smith reaction is normally inefficient and generates very low yields in products. The objective of this work was to verify the reactivity, site-selectivity, and stereospecificity of cyclopropanation of substituted 1,3-dienes, under drastic conditions of pressure (up to 4 kbar) and temperature (from 80 to 120°
Publicado em: 1993
-
14. Estudo quimico do Solanum granuloso-leprosum (Dunal)
From the optimized extraction method applied separately to the leaves, wood and fruits of Solanum granuloso-leprosum (Dunal), Solanaceae, we obtained the basic and the neutral extracts. The basic extracts afforded solasodine as the main alkaloidaI constituent of the plant, in addition to solaso-3,5-diene,b-glycoside-solasodine and traces of an undentified al
Publicado em: 1980
-
15. Inhibition of prostaglandin endoperoxide synthetase by thiol analogues of prostaglandin.
A variety of thiol compounds inhibited the enzymatic bis-oxygenation of 8,11,14-eicosatrienoic acid to prostaglandin G1, as examined with a purified preparation of prostaglandin endoperoxide synthetase (prostaglandin synthase; 8,11,14-eicosatrienoate, hydrogen-donor:oxygen oxidoreductase; EC 1.14.99.1) from bovine vesicular gland. The hydroperoxide cleavage
-
16. Production of Deepoxy-Diacetoxyscirpenol in a Culture of Fusarium graminearum†
Deepoxy-diacetoxyscirpenol was isolated from a laboratory culture of Fusarium graminearum grown on a solid rice substrate. It was characterized as 3-hydroxy-4,15-diacetoxy-trichothec-9,12-diene by proton nuclear magnetic resonance and mass spectrometry. This is the first report of the occurrence of this metabolite in a fungus culture.
-
17. Identification of Syn-Pimara-7,15-Diene Synthase Reveals Functional Clustering of Terpene Synthases Involved in Rice Phytoalexin/Allelochemical Biosynthesis1
Rice (Oryza sativa) produces momilactone diterpenoids as both phytoalexins and allelochemicals. Accordingly, the committed step in biosynthesis of these natural products is catalyzed by the class I terpene synthase that converts syn-copalyl diphosphate to the corresponding polycyclic hydrocarbon intermediate syn-pimara-7,15-diene. Here, a functional genomics
American Society of Plant Biologists.
-
18. Bimane fluorescent labels: labeling of normal human red cells under physiological conditions.
The bimane fluorescent labels, monobromobimane, dibromobimane, and monobromotrimethylammoniobimane, are derivatives of syn-9,10-dioxabimane:1,5-diazabicyclo[3.3.0]octa-3,6-diene-2,8-dione. They efficiently label hemoglobin (reactive thiol groups), membrane proteins, and glutathione of normal human red cells under physiological conditions. Monobromobimane and
-
19. Structures of deepoxytrichothecene metabolites from 3'-hydroxy HT-2 toxin and T-2 tetraol in rats.
3'-Hydroxy HT-2 toxin and T-2 tetraol, in vivo metabolites of T-2 toxin, were orally administered to Wistar rats, and four metabolites having a trichothec-9,12-diene nucleus, which were termed deepoxytrichothecenes, were newly found in the excreta. Their structures were confirmed as 3'-hydroxy-deepoxy HT-2, 3'-hydroxy-deepoxy T-2 triol, 15-acetyl-deepoxy T-2
-
20. Regio- and stereospecific oxidation of 9,10-dihydroanthracene and 9,10-dihydrophenanthrene by naphthalene dioxygenase: structure and absolute stereochemistry of metabolites.
The oxidation of 9,10-dihydroanthracene and 9,10-dihydrophenanthrene was examined with mutant and recombinant strains expressing naphthalene dioxygenase from Pseudomonas putida (NCIB 9816.4. Salicylate-induced cells of P. putida strain 9816/11 and isopropylthiogalactopyranoside-induced cells of Escherichia coli JM109(DE3)(pDTG141) oxidized 9,10-dihydroanthra
-
21. Purification and properties of cis-toluene dihydrodiol dehydrogenase from Pseudomonas putida.
The purification of (+)-cis-1(S),2(R)-dihydroxy-3-methylcyclohexa-3,5-diene dehydrogenase from cells of Pseudomonas putida grown with toluene as the sole source of carbon and energy is reported. The molecular weight of the enzyme is 104,000 at pH 9.7. The enzyme is composed of four apparently identical subunits with molecular weights of 27,000. The enzyme is
-
22. Calcium dependence of glucocorticoid-induced lymphocytolysis.
A potent glucocorticoid, triamcinolone acetonide (9alpha-fluoro-11beta, 16alpha,17alpha, 21-tetrahydroxypregna-1,4-diene-3,20-dione-16,17-acetonide) and a divalent cation ionophore (A23187) had similar effects in vitro on [3H]uridine uptake and on lysis of thymocytes of adrenalectomized rats. Removal of Ca2+ from the medium blunted the cytolytic action of tr
-
23. Gibberellin Biosynthesis in Maize. Metabolic Studies with GA15, GA24, GA25, GA7, and 2,3-Dehydro-GA91
[17-14C]-Labeled GA15, GA24, GA25, GA7, and 2,3-dehydro-GA9 were separately injected into normal, dwarf-1 (d1), and dwarf-5 (d5) seedlings of maize (Zea mays L.). Purified radioactive metabolites from the plant tissues were identified by full-scan gas chromatography-mass spectrometry and Kovats retention index data. The metabolites from GA15 were GA44, GA19,
American Society of Plant Physiologists.
-
24. Expression and mechanistic analysis of a germacradienol synthase from Streptomyces coelicolor implicated in geosmin biosynthesis
The PCR has been used to amplify a 2,181-bp ORF from Streptomyces coelicolor A3(2), designated SC9B1.20 (= SCO6073), encoding a protein of 726 amino acids and showing significant sequence similarity at the deduced amino acid level in both the N-terminal and C-terminal halves to the known sesquiterpene synthase pentalenene synthase. The full-length recombinan
The National Academy of Sciences.