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1.
Appl Microbiol Biotechnol ; 65(3): 263-7, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15069587

RESUMO

Bacillus subtilis SHS0133 cephalosporin-C deacetylase (CAH) overexpressed in Escherichia coli was immobilized on an anion-exchange resin, KA-890, using glutaraldehyde. The activity yield of immobilized enzyme was approximately 55% of the free enzyme. The pH range for stability of the immobilized enzyme (pH 5-10) was broader than that for free enzyme. The K(m)(app) value of immobilized enzyme for 7-aminocephalosporanic acid (7-ACA) was similar to that of the free enzyme. This immobilized enzyme obeyed Michaelis-Menten kinetics similar to those of the free enzyme. A batch-type reactor with a water jacket was employed for deacetylation of 7-ACA using CAH immobilized on KA-890. Ten kilograms of 7-ACA were completely converted to deacetyl 7-ACA at pH 8.0 within 90 min. The reaction kinetics agreed well with a computer simulation model. Moreover, the immobilized enzyme exhibited only a slight loss of the initial activity even after repeated use (52 times ) over a period of 70 days. This reaction will thus be useful for the production of cephalosporin-type antibiotics.


Assuntos
Bacillus subtilis/enzimologia , Hidrolases de Éster Carboxílico/metabolismo , Enzimas Imobilizadas/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Reatores Biológicos , Biotecnologia/métodos , Cefalosporinas/metabolismo , Estabilidade Enzimática , Temperatura Alta , Concentração de Íons de Hidrogênio , Cinética
2.
J Antibiot (Tokyo) ; 55(2): 155-64, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12002997

RESUMO

Two novel compounds, stachyflin and acetylstachyflin, have been isolated by solid-state fermentation of Stachybotrys sp. RF-7260. The structures of both metabolites, determined by detailed NMR analyses and X-ray crystallographic analysis, are novel with a pentacyclic moiety including cis-fused decalin. The absolute stereochemistry of stachyflins was determined by circular dichroism analysis. Stachyflin showed antiviral activity against influenza A virus (H1N1) in vitro with an IC50 value of 0.003 microM. Acetylstachyflin was about 77-fold less active than stachyflin.


Assuntos
Antivirais/química , Compostos Heterocíclicos de 4 ou mais Anéis/química , Indóis/química , Sesquiterpenos/química , Antivirais/isolamento & purificação , Antivirais/farmacologia , Fermentação , Compostos Heterocíclicos de 4 ou mais Anéis/isolamento & purificação , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Indóis/isolamento & purificação , Indóis/farmacologia , Vírus da Influenza A/efeitos dos fármacos , Estrutura Molecular , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/farmacologia , Relação Estrutura-Atividade
3.
J Antibiot (Tokyo) ; 55(3): 239-48, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12014438

RESUMO

Stachybotrys sp. RF-7260 was found to produce stachyflins, novel anti-influenza virus agents, under solid-state fermentation conditions. Feeding DL-lysine to a culture of Stachybotrys sp. RF-7260 induced the formation of the novel compounds, SQ-02-S-L2 and -L1, and feeding DL-valine the formation of SQ-02-S-VI and -V2. The structures of these metabolites were determined by detailed 2D NMR analyses in comparison with acetylstachyflin. SQ-02-S-L2 and -L1 have the lysine moiety and SQ-02-S-V1 has the valine moiety. SQ-02-S-V2 has an amidine moiety instead of the lactam moiety in acetylstachyflin. SQ-02-S-L2, -L1 and -V1, substituted on the lactam amide hydrogen, displayed only a low level of the antiviral activity. However, deacetyl SQ-02-S-V2 showed potent antiviral activity similar to stachyflin.


Assuntos
Antivirais/química , Compostos Heterocíclicos de 4 ou mais Anéis/química , Indóis/química , Sesquiterpenos/química , Stachybotrys/metabolismo , Animais , Antivirais/isolamento & purificação , Antivirais/farmacologia , Bovinos , Linhagem Celular , Fermentação , Compostos Heterocíclicos de 4 ou mais Anéis/isolamento & purificação , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Indóis/isolamento & purificação , Indóis/farmacologia , Vírus da Influenza A/efeitos dos fármacos , Rim/citologia , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/farmacologia , Relação Estrutura-Atividade
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