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181.
The structure of a minor component in the oxidation products of crude natural variotin oxidized with manganese dioxide is elucidated. The synthesis of the investigated compound, N-(6-oxo-2,4-trans, tralls-heptadienoyl) 2-pyrrolidonide, and the reduction of the substance are also described. 相似文献
182.
Masayuki Sakakibara Masanao Matsui 《Bioscience, biotechnology, and biochemistry》2013,77(5):1131-1137
The syntheses of three dl-demethylvariotins are described. 相似文献
183.
Mitsuru Ando Masayuki Nakagawa Toshiie Nakamura Kazuo Tomita 《Bioscience, biotechnology, and biochemistry》2013,77(4):803-809
Excretion, distribution and metabolism of the insecticide, Isoxathion, administered orally in male Wistar-strain rats, were investigated with a carbon-14 labeled chemical. During 96 hr, approximately 85% and 14% of the total radioactivity were excreted in the urine and feces. Distribution of isoxathion after oral administration in the rats was investigated by means of whole-body autoradiographic technique and measurement of radioactivity in the tissues. At least eleven radioactive metabolites were detected, four of which were structurally determined. They were 3-hydroxy-5-phenylisoxazole, 3-(β-d-glucopyranuronosyloxy)-5-phenylisoxazole, 5-phenyl-3-isoxazolyl sulfate and hippuric acid. 相似文献
184.
We reported previously that an ndhB gene disruptant, ΔndhB, had the same phenotype as wild-type tobacco plants under normal growth conditions. Two other groups have reported conflicting phenotypes with each other for ndhCKJ operon disruptants. Here, we generated two transformants in which the ndhCKJ operon was disrupted, and found that new transformants had the same phenotype as ΔndhB. After illumination with visible light, all ndh disruptants had higher levels of steady-state fluorescence than wild-type controls when measured under weak light, suggesting that reduction of the plastoquinone pool in ndh disruptants was greater than that in wild-type controls. The weak light itself could not reduce the plastoquinone much, so the reduction in the plastoquinone in the mutant was due to electron donation from stromal reductants generated during illumination with the strong light. These results supported the hypothesis that NAD(P)H dehydrogenase prevents overreduction in chloroplasts and suggested that chlororespiratory oxidase did not function under low light or in the dark. 相似文献
185.
Theoretical and experimental investigations were conducted on growth kinetics and substrate consumption of hydrogen bacterium Alcaligenes hydrogenophilus. The kinetic models proposed were evaluated by continuous cultures of A. hydrogenophilus under various conditions. The kinetic models closely simulated continuous cultures of A. hydrogenophilus. 相似文献
186.
Masayoshi Tabata Takahiro Kido Masayuki Totani Takashi Murachi 《Bioscience, biotechnology, and biochemistry》2013,77(7):1909-1910
(22R,23R,24S)-3α,5-Cyclo-22,23-diacetoxy-5a-ergostan-6-one (2b) is a new key intermediate of some naturally occurring brassinosteroids such as brassinolide (la), castasterone (lb), teasterone (lc) and typhasterol (Id). The cycloketone 2b was prepared in 10 steps via (22R,23R,24S)-6p- benzyloxy-3a,5-cyclo-22,23-dihydroxy-5a-ergostane (5) from stigmasterol. 2b was treated with a catalytic amount of /7-toluenesulfonic acid and sodium bromide to give an enone (7b), which was oxidized with osmium tetroxide and derived to give a 2a,3a-acetonide (8b). 8b was easily separated from its isomer by the use of silica gel column chromatography. 8b was oxidized with tri- fluoroperacetic acid and deacetylated to give la. 8b was deacetylated and deacetonized to give lb. 2b was treated with dilute sulfuric acid in acetic acid to give a 3/^-acetate (10). 10 was treated with sodium hydroxide to give lc. 2b was treated with hydrobromic acid to give a 3/i-bromide (12), which was treated with silver acetate to give a 3a-acetate (13). 13 was treated with sodium hydroxide to give Id. 相似文献
187.
Mitsuru Ando Toshiie Nakamura Masayuki Nakagawa 《Bioscience, biotechnology, and biochemistry》2013,77(12):2451-2456
Excretion, distribution and metabolism of the fungicide, hymexazol, (3-hydroxy-5-methylisoxazole), labeled with carbon-14 were examined after administration of a single oral dose to Wistar-strain rats. Hymexazol was rapidly absorbed and distributed in the tissues. During 96 hr, 97% of the total radioactivity was excreted in the urine and 0.89% in the feces, and 0.86% was found in the expired gasses for 24 hr. Two metabolites were detected in the urine, whose chemical structures were determined as 3-(β-d-glucopyranuronosyloxy)-5- methylisoxazole and 5-methyl-3-isoxazolyl sulfate. 相似文献
188.
Masayuki Nakagawa Toshiie Nakamura Kazuo Tomita 《Bioscience, biotechnology, and biochemistry》2013,77(11):2205-2208
Photolysis of 3-hydroxy-5-phenylisoxazole in methanol with a low-pressure mercury lamp afforded 5-phenyl-4-oxazolin-2-one, together with small amounts of benzoic acid and benzoylacetamide. Similarly, 3-hydroxy-5-methylisoxazole in distilled water afforded 5-methyl-4-oxazolin-2-one as the major product. Both isoxazoles were stable in sunlight for up to 20 days. 相似文献
189.
Teruo Miyazawa Seisuke Ito Yasuhiko Fujino 《Bioscience, biotechnology, and biochemistry》2013,77(7):1387-1391
Cerebroside was isolated from pea (Pisum sativum L.) seeds by solvent extraction, mild alkaline hydrolysis and silicic acid column chromatography. The purified material was identified as cerebroside by thin-layer chromatography and infrared spectrometry. Hydrolysates of the cerebroside were divided into fatty acid, sphingosine base and sugar fractions, and analysed, mainly by gas-liquid chromatography. The major fatty acid components were hydroxytricosanoic, hydroxydocosanoic and hydroxytetracosanoic acids. Dihydrosphingosine was the predominant sphingosine base. Only glucose was detected in the sugar fraction. Based on these results, one of the major species of pea cerebroside is suggested to be N-hydroxytricosanoyl-glucopyranosyl-dihydrosphingosine. 相似文献
190.
Desaturation of palmitic acid was investigated in an enzyme system prepared from rat liver. 2-trans-Hexadecenoic acid as well as 9-cis-hexadecenoic acid (palmitoleic acid) were found to be formed as monoenoic acid in this system. 相似文献