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Biomedical subjects

H Naganawa

Publications and source records attributed to H Naganawa.

At least 37 records · Page 2Linked to original sources
PubMed1999

Vinylamycin, a new depsipeptide antibiotic, from Streptomyces sp.

A new depsipeptide antibiotic, vinylamycin, was isolated from the culture broth of an actinomycete strain. The producing organism, designated MI982-63F1, was identified as a member of Streptomyces. Vinylamycin was isolated from the culture broth by extraction with EtOAc and purified by crystallization from EtOAc. The structure of vinylamycin was determined by spectroscopic analysis and degradation studies. Vinylamycin showed antimicrobial activities against Gram-positive bacteria including MRSA.

Animals↗
PubMed1998

Cremimycin, a novel 19-membered macrocyclic lactam antibiotic, from Streptomyces sp.

A novel 19-membered macrocyclic lactam antibiotic, cremimycin, was isolated from the culture broth of an actinomycete strain. The producing organism, designated MJ635-86F5, was identified as a member of Streptomyces. Cremimycin was isolated from the mycelial cake by extraction with CHCl3-MeOH and precipitation with hexane-MeOH. The structure of cremimycin was determined by spectroscopic study. Cremimycin showed broad antimicrobial activities against Gram-positive bacteria including MRSA.

Animals↗
PubMed1998

Nothramicin, a new anthracycline antibiotic from Nocardia sp. MJ896-43F17.

A new antibiotic designated nothramicin was isolated from the culture broth of Nocardia sp. MJ896-43F17 which was closely related to Nocardia brasiliensis. It was isolated by the Diaion HP-20 column chromatography, butyl acetate extraction and purified by HPLC. It inhibited the growth of mycobacteria at the concentration of 1.56 approximately 25 microg/ml. Nothramicin was revealed to be a new member of anthracycline antibiotics by the various spectroscopies.

Animals↗
PubMed1997

Resormycin, a novel herbicidal and antifungal antibiotic produced by a strain of Streptomyces platensis. II. Structure elucidation of resormycin.

A novel herbicidal antibiotic, resormycin, was isolated from the culture broth of Streptomyces platensis MJ953-SF5. The structure of resormycin is determined to be (2Z)-2-N-[2N-[(3S)-3,6-diaminoheptanoyl]-(2S)-3-hydroxyva lyl]amino-3- (4-chloro-3,5-dihydroxy)phenylpropenoic acid by spectroscopic analyses, degradation studies and X-ray crystallography.

Antifungal Agents↗
PubMed1997

Pyralomicins, novel antibiotics from Microtetraspora spiralis. IV. Absolute configuration.

The absolute configurations of pyralomicin la and pyralomicin 2a were determined by X-ray crystallographic analyses of crystalline 7'-O-p-bromobenzoylpyralomicin 1a and 2'-O-p-bromobenzoylpyralomicin 2a derived from pyralomicin 1a and pyralomicin 2a using anomalous scattering of the bromine atom. The absolute configurations of pyralomicins 1b approximately 1d and 2b approximately 2e were suggested to be the same as pyralomicin 1a and pyralomicin 2a, respectively, by comparing the circular dichroism spectra.

Actinomycetales↗
PubMed1997

Epoxyquinomicins A, B, C and D, new antibiotics from Amycolatopsis. III. Physico-chemical properties and structure determination.

The structures of epoxyquinomicins A (1), B (2), C (3) and D (4) were determined by spectroscopic studies. Compound 1 was determined to be (5R,6S)-2-(3-chloro-2-hydroxybenzoylamino)-5-hydroxymethyl-5,6-epo xy- 2-cyclohexene-1,4-dione. Compound 2 was revealed to be the dechlorinated derivative of 1. Compounds 3 and 4 were determined to be the reduced derivative of 2 and 1, respectively.

Actinobacteria↗
PubMed1996

Isolation and synthesis of novel farnesyl protein transferase inhibitors, valinoctins A and B, from Streptomyces strain MJ858-NF3.

Two novel farnesyl protein transferase inhibitors, valinoctins A (1) and B (2), were isolated from the fermentation broth of Streptomyces strain MJ858-NF3. The tentative structures of these compounds were elucidated from NMR and mass spectra as dipeptides consisting of valine and a novel amino acyl moiety. Four possible isomers of valinoctin A were synthesized, and the protected derivative of the appropriate compound was crystallized to give the relative stereochemistry of X-ray analysis. Since the valine residue of valinoctin A was determined to be the L-configuration by a chiral HPLC column, absolute configuration of valinoctin A was determined.

Animals↗
PubMed1996

Piperastatin A, a new selective serine carboxypeptidase inhibitor produced by actinomycete. II. Physico-chemical properties and structure determination.

Piperastatin A, a new inhibitor of serine carboxypeptidase, was discovered in the culture broth of Streptomyces lavendofoliae MJ908-WF13. The molecular formula of piperastatin A was established as C38H67N9C10 by HRFAB-MS and elemental analysis. The structure was determined to be N-formyl-allo Ile-Thr-Leu-Val-Pip-Leu-Pip (Pip = hexahydropyridadine-3-carboxylic acid) by various spectral analyses of piperastatin A and piperastatin A methylester.

Amino Acids↗
PubMed1996

Piperastatin B: a new selective serine carboxypeptidase inhibitor from Streptomyces lavendofoliae MJ908-WF13.

Piperastatin B, a new inhibitor of serine carboxypeptidase was purified from a culture broth of Streptomyces lavendofoliae MJ908-WF13 as a minor component by monitoring its inhibitory activity against carboxypeptidase Y (CP-Y). Its structure was determined to be N-formyl-Val-Thr-Leu-Val-Pip-Leu-Pip (pip: piperazic acid, hexahydropyridadine-3-carboxylic acid). Piperastatin B is a highly specific competitive inhibitor of CP-Y (Ki = 55 nM) with little effect on related enzymes and resembles the major component, piperastatin A, in these respects.

Amino Acids↗