Kazuyuki Dobashi

Learn More
A sulfated polysaccharide fraction, obtained from the hot-water extract of the brown seaweed, Ecklonia kurome by removing laminaran and the major part of alginic acid, gave sulfated polysaccharides (B-I, B-II, C-I, and C-II) by both anion-exchange chromatography on a column of Ecteola-cellulose and by fractional precipitation with ethanol containing 0.3%(More)
To measure quantitatively the intracellular distribution of cellular glutathione peroxidase (GPX) in rat hepatocytes, ultrathin sections were stained by a postembedding immunogold technique. GPX had a specific activity of 1670 Units/mg protein, and was purified 2050-fold from rat liver by means of heat denaturation, ammonium sulfate fractionation, and a(More)
In the course of screening program for inhibitors of angiogenesis, novel substances designated as ICM0301A approximately H (1 approximately 8) were isolated from the culture broth of Aspergillus sp. F-1491. ICM0301s inhibited the growth of human umbilical vein endothelial cells (HUVECs) induced by basic fibroblast growth factor (bFGF) with IC50 values of(More)
The present study reports the effect of ceramide generated by hydrolysis of membrane sphingomyelin with bacterial sphingomyelinase (SMase) and of cell-permeable ceramide analogues on the expression of manganese superoxide dismutase (MnSOD). Incubation of the rat primary astrocytes with SMase led to a time- and dose-dependent increase in MnSOD activity. The(More)
Streptomyces viridosporus A-914 was screened as a producer of an enzyme to effectively form chiral intermediates of 1,4-dihydropyridine calcium antagonists. The supernatant liquid of the growing culture of this strain exhibited high activity for enantioselective hydrolysis of prochiral 1,4-dihydropyridine diesters to the corresponding (4R) half esters. The(More)
4-Oxo-2-hexenal (4-OHE), which forms a 2'-deoxyguanosine (dG) adduct in a model lipid peroxidation system, is mutagenic in the Ames test. It is generated by the oxidation of omega-3 fatty acids and is commonly found in dietary fats, such as fish oil, perilla oil, rapeseed oil, and soybean oil. 4-OHE also forms adducts with 2'-deoxyadenosine (dA),(More)
Seven new macrolides having a 12-membered ring, which we termed pladienolides, were isolated from the fermentation broth of Streptomyces platensis Mer-11107. Six of the seven pladienolides inhibited hypoxia-induced reporter gene expression controlled by human VEGF promoter with IC50 values of 0.0018-2.89 microM. They also demonstrated growth-inhibitory(More)
Aspartic retroviral proteases play an important role in the processing of viral polyproteins into mature functional proteins1}. An inhibitor of avian myeloblastosis virus protease (AMV-protease) could be a possible candidate for antiviral-therapy and could be used, for example, as an anti-HIV agent2). In the course of screening for AMV-protease inhibitors,(More)
  • 1