RESUMEN
A new antibiotic, CJ-17,572 (I) was isolated from the fermentation broth of a fungus Pezicula sp. CL11877. The structure of I was determined to be a new equisetin derivative by spectroscopic analyses. The compound inhibits the growth of multi-drug resistant Staphylococcus aureus and Enterococcusfaecalis with IC50s of 10 and 20 microg/ml, respectively.
Asunto(s)
Antibacterianos/química , Pirrolidinonas/química , Tetrahidronaftalenos/química , Acetilación , Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Cromatografía Líquida de Alta Presión , Fermentación , Pruebas de Sensibilidad Microbiana , Pirrolidinonas/aislamiento & purificación , Pirrolidinonas/farmacología , Tetrahidronaftalenos/aislamiento & purificación , Tetrahidronaftalenos/farmacologíaRESUMEN
CJ-15,696 and 7 novel furopyridine antibiotics were isolated from the fungus Cladobotryum varium CL12284. Their structures were determined by X-ray crystallography and spectral analysis. Three biotransformed analogs were also prepared from CJ-15,696. CJ-15,696 showed moderate activity against various Gram-positive bacteria including some drug resistant strains such as methicillin resistant Staphylococcus aureus (MRSA).
Asunto(s)
Antibacterianos/química , Antifúngicos/química , Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Antifúngicos/aislamiento & purificación , Antifúngicos/farmacología , Biotransformación , Fermentación , Bacterias Grampositivas , Pruebas de Sensibilidad Microbiana , Relación Estructura-ActividadRESUMEN
High-throughput screening of microbial extracts using rat hepatic microsomal glucose-6-phosphatase (G6Pase) led us to find thielavin B as a G6Pase inhibitor with inhibition of glucose output from glucagon-stimulated hepatocytes. Further searching for more potent analogs identified 11 new thielavins F-P in addition to the known thielavins A and B from a fungus Chaetomium carinthiacum ATCC 46463. Thielavin G showed the strongest activity as a G6Pase inhibitor (IC50=0.33 microM), while the IC50 of thielavin B was 5.5 microM. According to the structure-activity relationship, including authentic thielavins C, D and 3 partial hydrolysates from thielavins A and B, 3 benzoic acid-units and carboxylic acid functions are essential for G6Pase inhibition.