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Biomedical subjects

M Shiro

Publications and source records attributed to M Shiro.

33 records · Page 2Linked to original sources
PubMed1996

Cloning of a cluster of chitinase genes from Aeromonas sp. No. 10S-24.

A gene encoding chitinases from Aeromonas sp. No. 10S-24 was cloned into Escherichia coli DH5 alpha using pUC19, and its nucleotides were sequenced. The chitinase gene was clustered in ORFs (open reading frame) 1 to 4, in a 8-kb fragment of DNA. ORF-1 consisted of 1608 bp encoding 535 amino acid residues, and ORF-2 consisted of 1425 bp encoding 474 amino acid residues. ORF-3 was 1617 bp long and encodes a protein consisting of 538 amino acids. ORF-4 encodes 287 amino acids of the N-terminal region. The amino acid sequences of ORF-1 and ORF-3 share sequence homology with chitinase D from Bacillus circulans, and chitinase A and B from Streptomyces lividans. The amino acid sequence of ORF-2 shared sequence homology with chitinase II from Aeromonas sp. No. 10S-24, and chitinase from Saccharopolyspora erythraea. A region of the sequence starting from Ala-28 of the amino acid sequence of ORF-3 coincided with the N-terminal amino acid sequence of chitinase III from Aeromonas sp. No. 10S-24.

Aeromonas↗
PubMed1996

Expression of the chitinase III gene of Aeromonas sp. no. 10S-24 in Escherichia coli.

The chitinase III gene of Aeromonas sp. No. 10S-24 was expressed in Escherichia coli. Production of chitinase III by E. coli was 3-fold higher than that of chitinases in the culture supernatant of Aeromonas sp. The enzyme from E. coli was purified and characterized. The molecular weight of the chitinase III from E. coli was estimated by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) to be 55,000. This agreed with the calculated molecular weight of the mature chitinase III (54,111). However, it was different from that of the enzyme from Aeromonas sp. It showed that the chitinase III from Aeromonas sp. had an additional sugar chain, causing the higher molecular weight. Chitinase III from E. coli had almost the same enzymatic properties as chitinase III from Aeromonas sp., but the specific activity of the chitinase III from E. coli is slightly higher than that of the native chitinase III. Both enzymes hydrolyzed chitosan (80% deacetylated) well.

Aeromonas↗
PubMed1987

Synthesis and oral antifungal activity of novel azolylpropanolones and related compounds.

To find orally active antifungal agents, novel imidazolyl- and 1,2,4-triazolylpropanolones I and related compounds II-IV were synthesized. Compounds I were derived from ketones V (method A), alpha-diketone IX (method B), alpha-hydroxy ketones X (method C), alpha-chloro ketone XII (method D), and enones VI (method E). Diols II, synthesized from I with NaBH4, were cyclized to five-membered cyclic compounds III by using N,N'-carbonyldiimidazole, thionyl chloride, N,N'-(thiocarbonyl)diimidazole, bromochloromethane, 2,2-dimethoxypropane, and cyclohexanone dimethyl ketal. Diols IV were synthesized from I by Grignard reaction (method F), hydroxymethylation of X (method G), and reaction of ketones XXI with 1-[(trimethylsily)methyl]-1,2,4-triazole (method H). Compounds I-IV were examined for their antifungal activities in vitro by evaluation of broth dilution MIC values against three species of fungi and the inhibitory effect on pseudomycelium of Candida albicans, and they were examined for oral efficacy in vivo against subacute systemic candidiasis in mice and superficial dermatophytosis in guinea pigs. Compounds 2, 12, 38, 39, and 92 exhibited strong oral antifungal activity. An asymmetric synthesis and the structure-activity relationships of the compounds examined are discussed.

1-Propanol↗
PubMed1987

Synthesis and antifungal activity of new 1-vinylimidazoles.

Carbonyl compounds I were subjected to an imidazole transfer reaction with N,N'-sulfinyldiimidazole or N,N'-carbonyldiimidazole to obtain the diimidazole II and the monoimidazole III. Various 1-vinylimidazoles IV, derived from o-hydroxyacetophenones by imidazole transfer reaction, were alkylated to furnish the title compounds V. The structure-activity relationships of these 1-vinylimidazole compounds V are described.

Candida albicans↗
PubMed1986

Synthesis and antiviral activity of sulfonamidobenzophenone oximes and sulfonamidobenzamides.

To find antiviral agents, various sulfonamidobenzophenone oximes (II) were synthesized from the appropriate m-sulfonamidobenzophenones by hydroxylamine reaction. The reaction products were generally obtained as syn/anti mixtures which were separable by fractional crystallization. The anti isomer had more potent antipoliovirus activity than the syn isomer. Various sulfonamidobenzamides (III) which were structurally related to II were synthesized by the reactions of amino-substituted benzamides with sulfuryl chloride or amines with (aminosulfonyl)benzoyl chloride. Antiviral activity was examined by the plaque-inhibition test. Compounds 5, 36, and 69 exhibited strong antipicornavirus activity. The structure-activity relationships are discussed.

Animals↗
PubMed1986

Relationships of the molecular structure of aldosterone derivatives with their binding affinity for mineralocorticoid receptor.

The molecular structures of 19-nor-11-deoxycorticosterone (III) and 21-hydroxypregna-4,11-diene-3,20-dione (IV) were determined by X-ray crystallographic analysis and the factors affecting the binding affinities for the mineralocorticoid receptor were examined with six aldosterone derivatives (I-VI) containing these two compounds. The most important factor was found to be the steric one; affinity increased with increasing flatness of the structure. The electronic factor may be a minor influence although a good relationship was found between the affinity and the 13C-NMR chemical shift of the C(5) atom. The factor playing no role in the binding is the hydrophobic one.

Aldosterone↗