16-Methyloxazolomycin, a new antimicrobial and cytotoxic substance produced by a Streptomyces sp.

search for novel antimicrobial agents from microorganisms, an actinomycete strain Streptomyces sp. isolated from a soil sample collected in Taejon, Korea, was found to produce a new antibacterial 16-methyloxazolomycin (1). In this paper, we describe the production, isolation, structural elucidation and biological activities of 1. The strain was cultured in the seed mediumconsisting of glucose 2%, starch 1%, soybean flour 2.5%, yeast extract 0.4%, NaCl 0.2%, K2HPO4 0.005% and beef extract 0.1% (adjusted to pH 7.3 before sterilization). The seed culture was carried out on a rotary shaker (250rpm) at 28°C for 24 hours in 500-ml Erlenmeyer