RESUMEN
A new chitinase inhibitor, named argifin, was isolated from the cultured broth of a fungal strain FTD-0668. The strain was identified as Gliocladium sp. from morphological characteristics. The IC50 value of argifin against Lucilia cuprina chitinase was 3.7 microM. Argifin arrested the moult of cockroach larvae upon injection into the ventral abdominal part.
Asunto(s)
Quitinasas/antagonistas & inhibidores , Cucarachas/efectos de los fármacos , Inhibidores Enzimáticos/metabolismo , Inhibidores Enzimáticos/farmacología , Hongos Mitospóricos/metabolismo , Péptidos Cíclicos/metabolismo , Péptidos Cíclicos/farmacología , Animales , Bacterias/efectos de los fármacos , División Celular/efectos de los fármacos , Línea Celular/efectos de los fármacos , Cucarachas/crecimiento & desarrollo , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos/métodos , Concentración 50 Inhibidora , Larva/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Hongos Mitospóricos/clasificaciónRESUMEN
Gliocladium roseum KF-1040, a marine isolate, was found to produce a series of new inhibitors of diacylglycerol acyltransferase (DGAT). Four active compounds, designated roselipins 1A, 1B, 2A and 2B, were isolated from the fermentation broth of the producing strain by solvent extraction, ODS column chromatography and preparative HPLC. The highest production of roselipins was observed when cultured in the medium containing natural sea water. Roselipins inhibit DGAT activity with IC50 values of 15 approximately 22 microM in an enzyme assay system using rat liver microsomes.
Asunto(s)
Aciltransferasas/antagonistas & inhibidores , Inhibidores Enzimáticos/aislamiento & purificación , Inhibidores Enzimáticos/farmacología , Ácidos Grasos/aislamiento & purificación , Ácidos Grasos/farmacología , Hongos Mitospóricos/metabolismo , Monosacáridos/aislamiento & purificación , Monosacáridos/farmacología , Animales , Diacilglicerol O-Acetiltransferasa , Evaluación Preclínica de Medicamentos , Inhibidores Enzimáticos/metabolismo , Ácidos Grasos/metabolismo , Fermentación , Concentración 50 Inhibidora , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica de Rastreo , Hongos Mitospóricos/clasificación , Hongos Mitospóricos/ultraestructura , Monosacáridos/metabolismo , RatasRESUMEN
A bioassay method detecting deformations of mycelia germinated from conidia of Pyricularia oryzae P-2b, has been modified to give quantitative estimations. The method was first developed using antimitotic agents which showed characteristic curling effect. Morphological deformations include curling, swelling, hyper-divergency, beads shape and so on, and inhibition of the germination was also observed. For quantitative estimations, indices were introduced for the hyphal growth inhibition and a quantity of conidia in each assay cell and concentration of test solutions were adjusted. Details of the modified method and the application to screening assay of marine fungi isolated in Yap Islands are described. Eight strains of 109 tested showed morphological deformations, and chaetoglobosin A was isolated from the broth filtrate of a strain assigned to Chaetomium sp. This bioassay is a cheap, quick and easy method to be applied to the primary screening for antimitotic and antifungal substances from natural sources.
Asunto(s)
Antifúngicos/farmacología , Antineoplásicos/farmacología , Evaluación Preclínica de Medicamentos/métodos , Mitosis/efectos de los fármacos , Hongos Mitospóricos/efectos de los fármacos , Chaetomium/metabolismo , Citocalasinas/farmacología , Hongos/metabolismo , Alcaloides Indólicos , Indoles/química , Indoles/metabolismo , Indoles/farmacología , Biología Marina , Hongos Mitospóricos/fisiologíaRESUMEN
A new 16-membered macrolide designated as rhizoxin was isolated as a toxin produced by Rhizopus chinensis, the causal agent of rice seedling blight . The skeletal structure was determined by detailed NMR spectroscopic investigation of this compound and of its derivatives. Rhizoxin induced at a concentration of 10 ng/ml abnormal swelling of rice seedling roots, which is one of the characteristic symptoms of this disease. This compound also exhibited potent antifungal activity but little effect against bacteria.