Salinirifamycins A−E: Rifamycin S Derivatives from the Brazilian Marine Actinomycete Salinispora arenicola.

SILVA, A. B. da; PINTO, F. C. L.; SILVEIRA, E. R.; PAULO, T. de F.; WILKE, D. V.; FERREIRA, E. G.; COSTA-LOTUFO; CANUTO, K. M.; MARINHO FILHO, J. D. B.; BARROS, A. B.; NUZZO, G.; FONTANA, A.; MONTEIRO, R. K. V.

Salinirifamycins A−E: Rifamycin S Derivatives from the Brazilian Marine Actinomycete Salinispora arenicola.

Autores

MARINHO FILHO, J. D. B.

BARROS, A. B.

Descripción

Five new rifamycin derivatives, named salinirifamy- cins A−E (1−5), were isolated from a Brazilian marine Salinispora arenicola (BRA-213) strain extract. The structures of the new rifamycins were elucidated using a combination of NMR, IR, UV, and MS spectroscopic techniques, quantum-chemical calculations (DFT-calculated 13 C NMR chemical shifts and DP4+ probability analysis), and comparison of experimental and calculated electronic circular dichroism (ECD) spectra. Compounds 1, 2, and 4 displayed antibacterial activity against Staphylococcus aureus and Enterococcus faecalis with MIC values ranging from 2.0 to 125.0 μg/ mL, whereas 5 exhibited an MIC of 0.02 μg/mL to S. aureus, similar to the positive control rifampicin (MIC 0.03 μg/mL).