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Biomedical subjects

Y Okami

Publications and source records attributed to Y Okami.

At least 37 records · Page 2Linked to original sources
PubMed1992

TA-3037A, a new inhibitor of glutathione S-transferase, produced by actinomycetes. I. Production, isolation, physico-chemical properties and biological activities.

TA-3037A, a new inhibitor of glutathione S-transferase was discovered in the fermentation broth of Streptomyces sp. TA-3037. It was purified by chromatography followed by solvent extraction and then isolated as yellow needles. TA-3037A has the molecular formula of C16H11NO4. It was competitive with the substrate, and the inhibition constant (Ki) was 4.9 microM.

Cells, Cultured↗
PubMed1989

Altemicidin, a new acaricidal and antitumor substance. I. Taxonomy, fermentation, isolation and physico-chemical and biological properties.

Screening of new insecticidal and acaricidal antibiotics was carried out with reference to anti-brine shrimp activity from actinomycete strains isolated from marine environments. Of 200 actinomycete isolates, one isolate was found to produce a new substance, altemicidin. The strain was isolated from sea mud collected at Gamo, Miyagi Prefecture, Japan, and identified as Streptomyces sioyaensis SA-1758. Altemicidin was purified by Diaion CHP-20P and Sephadex LH-20 column chromatographies. The molecular formula was determined as C13H20N4O7S by elemental analysis, MS and 13C NMR spectrum. Altemicidin showed not only acaricidal activity but also antitumor activity. The compound showed no antimicrobial activity except the inhibitory activity to Xanthomonas strains.

Alkaloids↗
PubMed1989

Altemicidin, a new acaricidal and antitumor substance. II. Structure determination.

The structure of altemicidin, a new acaricidal and antitumor agent, was determined to be (1R,2S,3aR,7aS)-4-carbamoyl-2-hydroxy-6-methyl-1-(sulfamo ylacetamido)-2,3,3a,6, 7,7a-hexahydro-6-azaindene-1-carboxylic acid by a combination of spectroscopic and X-ray crystallographic analysis of its derivatives. Altemicidin is a monoterpene alkaloid.

Alkaloids↗
PubMed1989

Biosynthetic similarity between Streptomyces tenjimariensis and Micromonospora olivasterospora which produce fortimicin-group antibiotics.

The profile of bioconversion products of istamycin (IS) components by a blocked IS mutant of Streptomyces tenjimariensis that lost IS-productivity suggested a possible biosynthetic pathway of IS similar to that of fortimicin (FT) by Micromonospora olivasterospora. Both organisms are resistant to the antibiotics produced by each other. Based on these similarities, they were examined for their capability to convert an FT-intermediate (FT-B) and IS-intermediates (IS-A0 and -B0) through their biosynthetic pathways. S. tenjimariensis formed 1-epi-FT-B, 2''-N-formimidoyl-FT-A (= dactimicin) and 1-epidactimicin (a new antibiotic) from FT-B. On the other hand, M. olivasterospora converted IS-A0 and -B0 to 2''-N-formimidoyl-IS-A (= IS-A3) and -B (= IS-B3), respectively. Thus, the similarity in antibiotic biosynthesis was confirmed between these FT-group antibiotic-producing organisms. It was also found that the major fermentation product of M. olivasterospora is not FT-A (astromicin) but dactimicin.

Aminoglycosides↗
PubMed1988

Thrazarine, a new antitumor antibiotic. I. Taxonomy, fermentation, isolation and biological properties.

Thrazarine, O-[(3R)-2-diazo-3-hydroxybutyryl)]-L-serine, is a new antitumor antibiotic produced by Streptomyces coerulescens MH802-fF5. Thrazarine was isolated from culture filtrate by Sephadex LH-20 column chromatography and reversed phase HPLC. Thrazarine induced cytolysis of tumor cell lines co-cultured with nonactivated macrophages. This effect was tumor specific because the nontumorigenic cells were not lysed by macrophages in the presence of thrazarine. Thrazarine inhibited DNA synthesis and growth of tumor cells directly. It showed neither antimicrobial activity nor the inhibition of transamidation reactions in contrast to azaserine. Toxicities of thrazarine were much weaker than those of azaserine.

Animals↗
PubMed1988

Thrazarine, a new antitumor antibiotic. II. Physico-chemical properties and structure determination.

A new antitumor antibiotic thrazarine was soluble in water and positive to anisaldehyde-sulfuric acid and ninhydrin color reactions. The absolute structure of thrazarine was determined to be O-[3R)-2-diazo-3-hydroxybutyryl)-L-serine by acid hydrolysis, spectroscopic analysis and X-ray crystallographic analysis. Structurally, thrazarine was a new member of azaserine group antibiotics.

Antibiotics, Antineoplastic↗
PubMed1987

Nucleotide sequence of the streptomycinphosphotransferase and amidinotransferase genes from Streptomyces griseus.

Genes for streptomycin phosphotransferase and inosamine-P-amidinotransferase from a streptomycin-producing Streptomyces griseus were cloned on a 3.8kb BamHI-SphI fragment in S. lividans using the multicopy cloning vector pIJ702. The nucleotide sequence of this 3.8kb fragment was determined and the coding sequences for the two genes were identified by comparison with the amino-terminal sequences of the two enzymes purified from S. lividans clones.

Amidinotransferases↗
PubMed1987

Bisucaberin, a new siderophore, sensitizing tumor cells to macrophage-mediated cytolysis. I. Taxonomy of the producing organism, isolation and biological properties.

Alteromonas haloplanktis strain SB-1123 isolated from deep-sea mud produced a new siderophore, bisucaberin. Bisucaberin rendered tumor cells susceptible to cytolysis mediated by murine peritoneal macrophages which were elicited by Proteose peptone and not yet activated by lymphokine. Bisucaberin exerted its sensitizing activity by both the preincubation with tumor cells and the addition to co-culture of macrophages and tumor cells. The activity of bisucaberin was specifically inhibited by ferric ion. Bisucaberin showed direct cytostasis for tumor cells but did not cause cytolysis in the absence of macrophages. Cytostasis by bisucaberin was attributable to the specific inhibition of DNA synthesis in tumor cells.

Antineoplastic Agents↗
PubMed1987

Bisucaberin, a new siderophore, sensitizing tumor cells to macrophage-mediated cytolysis. II. Physico-chemical properties and structure determination.

The structure of bisucaberin, a new siderophore, was determined to be 1,12-dihydroxy-1,6,12,17-tetraazacyclodocosane-2,5,13,16-tetron e by spectroscopic analysis and X-ray crystallographic analysis. The molecule of bisucaberin consists of a cyclic dimer of 1-hydroxy-1,6-diazaundecane-2,5-dione moiety and is closely related to nocardamine, the trimer of the same moiety.

Antineoplastic Agents↗
PubMed1986

Bagougeramines A and B, new nucleoside antibiotics produced by a strain of Bacillus circulans. I. Taxonomy of the producing organism and isolation and biological properties of the antibiotics.

A bacterial isolate from soil, designated as TB-2125 had a unique pattern of multiple resistance to aminoglycoside antibiotics (AG) and produced new nucleoside antibiotics. Taxonomic properties of this strain fell into those of Bacillus circulans, providing unique characteristics such as strict susceptibility to acidic pH, motility of colony as well as multiple AG-resistance. Two new antibiotics which were named bagougeramines A and B had a broad antimicrobial activity and a specific activity against the two spotted spider mite.

Animals↗
PubMed1986

Bagougeramines A and B, new nucleoside antibiotics produced by a strain of Bacillus circulans. II. Physico-chemical properties and structure determination.

Bagougeramines A and B obtained as sulfates were soluble in water and positive to Sakaguchi, chlorine-tolidine and ninhydrin color reactions. Their structures were determined by acid hydrolysis and spectroscopic analysis. Structurally they were closely related to gougerotin and they contained the guanidino-D-alanine instead of the serine residue in gougerotin. Bagougeramine B had the spermidine instead of the 6'-NH2 in structure of bagougeramine A.

Anti-Bacterial Agents↗