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Biomedical subjects

J Shoji

Publications and source records attributed to J Shoji.

At least 91 records · Page 5Linked to original sources
PubMed1977

Isolation of two new polymyxin group antibiotics. (Studies on antibiotics from the genus Bacillus. XX).

Two new members of polymyxin group antibiotics, polymyxins S1 and T1, were isolated from the culture broths of strains identified as Bacillus polymyxa Rs-6 and Bacillus polymyxa E-12, respectively. These antibiotics are strongly basic substances, their hydrochloric acid salts are soluble in water and methanol. They are primarily active against Gram-negative bacteria in vitro and in vivo though polymyxin T1 exhibits higher activities against Gram-positive bacteria than other polymyxin group antibiotics.

Bacillus↗
PubMed1977

The structure of polymyxin S. (Studies on antibiotics from the genus Bacillus. XXI).

Amino acid analysis on the acid hydrolyzate of polymyxin S1 revealed its amino acid composition. Isolation of the constituent amino acids and measurement of their optical activities clarified their chiralities: Dab(5L), Thr(3L), Ser(1D) and Phe(1D). The constituent fatty acid was identified with anteisononanoic acid by gas chromatography and mass spectrometry. By the action of polymyxin acylase, deacyl polymyxin S was obtained. Successive EDMAN degradation reaction on deacyl polymyxin S revealed the amino acid sequence. Further evidence for the structure of polymyxin S1 was obtained by partial acid hydrolysis on tetra-(DNP)-polymyxin S1.

Amino Acid Sequence↗
PubMed1977

The structure of polymyxin T1. (Studies on antibiotics from the genus Bacillus. XXII).

Amino acid analysis of the acid hydrolyzate of polymyxin T1 revealed the amino acid composition. Isolation of the constituent amino acids and measurement of their optical activities clarified their chiralities. These were 2,4-diaminobutyric acid (6L), Thr(1L), Leu(2L) and Phe(1D). The constituent fatty acid was identified as anteisononanoic acid by gas chromatography and mass spectrometry. Deacylation with polymyxin acylase afforded deacyl polymyxin T. Successive EDMAN degradation on deacyl polymyxin T revealed most of its amino acid sequence. The chemical cleavage reaction for fragmentation of threonyl peptide amino acid sequence. The chemical cleavage reaction for fragmentation of threonyl peptide on penta(DNP)-polymyxin T1 cleaved it at the C-terminal side of the Thr residue to afford a DNP-octapeptide, whose sequence was clarified by EDMAN degradation. Thus, the structure of polymyxin T1 was determined.

Amino Acid Sequence↗
PubMed1976

The total structure of cerexin A (studies on antibiotics from the genus Bacillus. XVI.

The constituent fatty acid of cerexin A was elucidated to be beta-hydroxy isoundecanoic acid by gas chromatography, mass spectrometry and nuclear magnetic resonance. The asparaginyl asparagine linkage in the amino acid sequence of the antibiotic, which has been previously described, was proved to be a normal alpha-carboxylpeptide bond by dehydration-reduction procedure. The three asparagine residues in the sequence were isolated separately and their chiralities were determined. The structure of cerexin A was concluded from the above results.

Amino Acid Sequence↗
PubMed1976

The structure of cerexin B (studies on antibiotics from the genus Bacillus. XVII).

The structure of cerexin B was examined. The constitutent fatty acids were elucidated by gas chromatography and mass spectrometry to be beta-hydroxy isodecanoic acid, beta-hydroxy decanoic acid, beta-hydroxy isoundecanoic acid and beta-hydroxy anteisoundecanoic acid. The configurations of constituent amino acids were determined as asparagine (2D, 1L), valine (D), phenylalanine (D), allo-threonine (D), tryptophan (D), and allo-isoleucine (D) from their optical activities. Treatment with conc. hydrochloric acid cleaved at the gamma-hydroxylysine residue to give two peptide fragments, one of which (the N-terminal side) was then deacylated with Polymyxin Acylase. Their amino acid sequences were examined by EDMAN degradation. From the results and analogy to cerexin A, the structure of cerexin B was deduced.

Amino Acid Sequence↗
PubMed1976

Production and isolation of cerexins C and D studies on antibiotics from the genus Bacillus. XVII.

From the culture broth of Bacillus cereus 60-6, in which antibiotic production was improved a new antibiotic, named cerexin C, was isolated. Similarly, a new antibiotic, cerexin D was isolated from the culture broth of Bacillus cereus Gp-3. Cerexins C and D are closely related to cerexins A and B in their physico-chemical and antimicrobial properties. In fact cerexins C and D are peptides essentially identical with cerexins A and B except for the presence of a lysine residue in place of the gamma-hydroxylysine residue.

Amino Acids↗
PubMed1976

Isolation of three new antibiotics, thiocillins I, II and III, related to micrococcin P. Studies on antibiotics from the genus Bacillus. VIII.

Thiocillins I and II were isolated from the culture broth of Bacillus cereus G-15, and thiocillins II and III from that of Bacillus badius AR-91. Also, the former two were probably produced by Bacillus megatherium I-13. These antibiotics active against Gram-positive bacteria are soluble in a mixture of chloroform and methanol, show characteristic ultraviolet absorptions (maxima at ca. 275 nm and ca. 348 nm), and contain a high content of sulfur, as much as approximately 15%. They are related to each other and also to micrococcin P, but differentiated by chromatographic behaviours.

Animals↗
PubMed1976

Isolation of brevistin, a new peptide antibiotic. Studies on antibiotics from the genus Bacillus. IX.

A new peptide antibiotic, brevistin, was isolated from the culture broth of Bacillus brevis 342-14. Brevistin is an acylpeptide with an approximate empirical formula of C63H91N15O18 containing aspartic acid, threonine, glycine, valine, isoleucine, phenylalanine, tryptophan and 2,4-diaminobutyric acid. The antibiotic is soluble in acid and alkaline water. Its hydrochloride is soluble in methanol. Brevistin is active against Ggam-positive bacteria in vitro and in vivo, and is of low toxicity to mice.

Animals↗
PubMed1976

The structure of brevistin. Studies on antibiotics from the genus Bacillus. X.

Acid hydrolysis revealed the constituent amino acids by brevistin as follows: aspartic acid (D-form 2, L-form 1), L-threonine (1), glycine (1), sum of L-valine and L-isoleucine (1), L-phenylalanine (1), L-trytophan (1), and 2,4-diaminobutyric acid (D-form 1, L-form 1). The constituent fatty acid was elucidated to be anteisononanoic acid by gas chromatography-mass spectrometry. A lactone linkage was proved between phenylalanine and the hydroxy group of threonine. Opening the lactone ring with dilute alkali afforded brevistinic acid. Deacylation with an enzyme preparation, Polymyxin Acylase, gave deacyl brevistinic acid. Cleavage reaction with N-bromosuccinimide, sequential analysis by EDMAN degradation and some additional evidences clarified the total structure of brevistin.

Acetates↗
PubMed1976

Isolation of a new antibiotic, laterosporamine. Studies on antibiotics from the genus Bacillus. XIII.

A new antibiotic, named laterosporamine, was isolated from the culture broth of Bacillus laterosporus 340-19. The antibiotic is active against Gram-positive and Gram-negative bacteria in vitro and in vivo. It is a water-soluble basic substance, positive to ninhydrin, SAKAGUCHI'S and DRAGENDORFF'S reagents. A non-peptidic structure with an approximate empirical formula C17H35N7O4 was suggested.

Animals↗