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991.
992.
The effect of ten derivatives of carbonylcyanide phenylhydrazone on growth of bacteria, yeast and different species of filamentous
fungi was investigated. In yeast and mitochondria isolated from rat liver the effect of these derivatives on the respiratory
activity was also followed. The relative efficiency of the individual derivatives of earbonylcyanide phenylhydrazone was determined
on the basis of the results obtained. It was shown that derivatives, in which the substituent on the benzene ring causes simultaneously
an increase of acidity and lipophilicity of the derivative as compared with the non-substituted carbonylcyanide phenylhydrazone
(4-trifluoromethoxy-, 3-chloro-, 4-chloro and 3,4-dichloroderivatives) were most effective. 相似文献
993.
Separation and properties of α-mannosidase and mannanase from the basidiomycetePhellinus abietis 总被引:1,自引:1,他引:0
Proteins of a crude enzyme preparation obtained from the cultivation medium of the basidiomycetePhellinus abietis were separated by gel filtration and ion-exchange chromatography. The preparation contained a minimum of three enzymes capable
of splitting α-d-mannosidic bonds: α-mannosidase, exomannanase, and endomannanase, which were separated. Some properties of the mannanase
complex of the crude enzyme preparation, and of a partially purified α-mannosidase were examined. The mannanase complex exhibited
two pH optima, its temperature optimum being at 46 °C The pH optimum of purified α-mannosidase was at pH 5.0, the temperature
optimum was at 60 °C; the enzyme had a relatively high heat stability. The Km of α-mannosidase forp-nitrophenyl α-d-mannopyranoside was 1.5 x 10−5 M. Pure α-mannosidase did not split mannan. 相似文献
994.
995.
Crystal-containing organelles in cells of virus infected plants lying at chloroplasts and mitochondria are identical with single membrane-bound microbodies containing crystals of catalase described in healthy plants. Massive complex inclusions caused by turnip mosaic virus very frequently contain the same microbodies with crystal inclusions; that phenomenon may be related to some pathophysiological changes of virus infected plants. Comparable proteinaceous crystals, but not lying within microbodies limited by a membrane, may also be found in cytoplasm of infected cells. These crystals are sometimes surrounded by a substance resembling the microbody matrix. Disintegrated cytoplasm of virus infected cells may also contain the same crystals lying free in “empty spaces”. Cytopathological effects responsible for this phenomenon and possible artifacts as well are discussed. 相似文献
996.
997.
Judith Huerta-Bahena Rafael Villalobos-Molina J.Adolfo García-Sáinz 《Life sciences》1982,30(20):1757-1762
Cycloheximide, a widely used inhibitor of protein synthesis, stimulates glycogenolysis, gluconeogenesis and ureogenesis in isolated rat hepatocytes. The effects of cycloheximide were compared to those of norepinephrine. Both agents, cycloheximide and norepinephrine, produced slight increases in the levels of cyclic AMP (30% increases) which were blocked by propranolol. Interestingly, it was found that the metabolic actions of norepinephrine and cycloheximide (stimulation of glycogenolysis, gluconeogenesis and ureogenesis) were only slightly diminished by the β adrenergic antagonist propranolol but abolished by the selective α1 adrenergic antagonist prazosin. The ability of cycloheximide to inhibit protein synthesis was not affected by either prazosin or propranolol. It is concluded that the stimulation of glycogenolysis, gluconeogenesis and ureogenesis by cycloheximide in rat hepatocytes, is an effect of the antibiotic independent of its ability to inhibit protein synthesis and that is mediated through activation of α1 adrenoceptors. The adrenergic activity of cycloheximide should be considered when this drug is used as an inhibitor of protein synthesis. 相似文献
998.
Summary Gene hsrM (nonB) of Bacillus subtilis 168, causing non-permissiveness to phage SP10 (Saito et al. 1979) and reduced plating efficiency of unmodified phage 105, is responsible for non-permissiveness of B. subtilis 168 for phages 15 and PZA. Upon transformation to sporulation deficiency (allele spoOA) B. subtilis 168 becomes permissive for 15 and PZA and loses the ability to restrict 105. spoOA str-1 double transformants of B. subtilis 168, however, retain the restriction 168 and non-permissiveness for 15 and PZA phages, in spite of their Spo– phenotype. Therefore it appears that a functional product of the spoOA gene is required for expression of gene hsrM in wild-type bacteria, but is not essential in streptomycin-resistant bacteria. Phage genomes (PZA) were trapped in spores of the restriction deficient strain with much higher efficiency than in the wild-type. 相似文献
999.
From the aerial part of Teucrium chamaedrys a new neo-clerodane diterpenoid, dihydroteugin, has been isolated, besides the previously known diterpenoids teucrin A and teugin. The structure of dihydroteugin, (12S)-15,16-epoxy-2β,6β-dihydroxy-neo-cleroda-13(16), 14-diene-18,19:20,12-diolide, was established by chemical and spectroscopic means and by partial synthesis from teugin. 相似文献
1000.
Silvia M.C. Dias João B. Fernandes José G.S. Maia Otto R. Gottlieb Hugo E. Gottlieb 《Phytochemistry》1982,21(7):1737-1740
The trunk wood of an Amazonian Aniba (Lauraceae) species contains, besides dillapiol and the benzodioxane-type neolignan eusiderin, four bicyclo(3.2.1)octanoid neolignans. These comprise representatives of the canellin-type: the known methoxycanellin-A and the novel compounds characterized as (1R, 3S, 4S, 5S, 6S, 7R)-1-allyl-4-hydroxy-3, 5-dimethoxy-7-methyl-6-(3′-methoxy-4′, 5′-methylenedioxyphenyl)-8-oxo-bicyclo(3.2.1)octane; (1R, 3S, 4S, 5S, 6S, 7R)-1-allyl-4-hydroxy-3, 5-dimethoxy-7-methyl-6-(3′, 4′, 5′-trimethoxyphenyl)-8-oxobicyclo(3.2.1)octane and (1R, 4R, 5R, 6S, 7R, 8S)-1-allyl-4, 8-dihydroxy-5-methoxy-7-methyl-6-(3′-methoxy-4′,5′-methylenedioxyphenyl)-3-oxobicyclo(3.2.1)octane. 相似文献