RESUMO
A novel kappa opioid receptor binding inhibitor CJ-15,208 (I) was isolated from the fermentation broth of a fungus, Ctenomyces serratus ATCC15502. The structure of I was determined to be a cyclic tetrapeptide consisting of one tryptophan, one D-proline, and two L-phenylalanine. Compound I was a selective binding inhibitor for the kappa opioid receptor: 47 nM (IC50) for kappa, 260 nM for mu, and 2,600 nM for delta. In the electrically-stimulated twitch response assay of rabbit vas deferens I recovered the suppression by a kappa agonist asimadoline with an ED50 of 1.3 microM, indicating that it is a kappa antagonist.
Assuntos
Arthrodermataceae , Antagonistas de Entorpecentes/isolamento & purificação , Receptores Opioides kappa/antagonistas & inibidores , Animais , Estimulação Elétrica , Fermentação , Cobaias , Masculino , Antagonistas de Entorpecentes/química , Antagonistas de Entorpecentes/farmacologia , Coelhos , Relação Estrutura-Atividade , Ducto Deferente/efeitos dos fármacosRESUMO
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.