Sealutomicins, new enediyne antibiotics from the deep-sea actinomycete Nonomuraea sp. MM565M-173N2.

Abstract

A Nonomuraea sp. strain MM565M-173N2 was isolated from deep-sea sediment off the Sanriku coast, and new antibiotics were evaluated against carbapenem-resistant Enterobacteriaceae (CRE), which is a problematic group of bacteria because of their antimicrobial resistance. From 220\u2009l of fermented broth from strain MM565M-173N2, we isolated four new antibiotics by gel filtration and HPLC, designated as sealutomicins A (1.8\u2009mg), B (1.5\u2009mg), C (0.8\u2009mg), and D (0.8\u2009mg). Their structures were determined from MS, NMR, and CD spectra. Sealutomicin A was found to be a new enediyne antibiotic, while sealutomicins B-D were aromatized products from sealutomicin A. Sealutomicin A showed strong antibacterial activity (MIC 0.05-0.2\u2009μg\u2009ml-1) against CRE.