RESUMEN
Three new cytotoxic 3,6-disubstituted indoles (1-3) were isolated from the mycelium of a strain identified as Streptomyces sp. (BL-49-58-005), which was separated from a Mexican marine invertebrate, and their structures established by analysis of NMR and mass spectral data. GI(50) values for 1 and 2 in cytotoxic bioassays against a panel of 14 different tumor cell lines were estimated at micromolar range, while compound 3 showed no activity in the same assays.
Asunto(s)
Antineoplásicos/aislamiento & purificación , Indoles/aislamiento & purificación , Streptomyces/química , Antineoplásicos/química , Antineoplásicos/farmacología , Línea Celular Tumoral/efectos de los fármacos , Neoplasias del Colon , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Indoles/química , Indoles/farmacología , Concentración 50 Inhibidora , Leucemia , Masculino , México , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Neoplasias Pancreáticas , Neoplasias de la PróstataRESUMEN
The newly isolated strain Streptomyces sp. RSP9 produces two thiopeptides; one of them is methylsulfomycin I, which shows potent antibiotic activity against several gram-positive bacteria such as Micrococcus luteus and Staphylococcus aureus. The other is a new thiopeptide named radamycin. In the present work, this compound was purified and tested against several microorganisms and no antibiotic activity was detected in the assays. However, it does have a very strong capacity as an inducer of the tipA promoter, and indeed is the first reported molecule with tipA promoter induction capacity without detectable antibiotic activity. Induction of the tipA promoter also occurs with methylsulfomycin I.