New pacidamycins produced by Streptomyces coeruleorubidus, NRRL 18370.

were isolated.1^ Here we report the production, isolation, structure elucidation, and biological activities of pacidamycins D (1), 4N (2), and 5T (3). A fresh culture of strain NRRL18730 was inoculated into four 250-ml baffled shake flasks, each containing 50 ml of seed medium consisting of glucose monohydrate 1.0%, soluble starch 1.5%, yeast extract 0.5%, casitone 0.5%, CaCO3 0.1% (pH adjusted to 7.0 before sterilization). The flasks were incubated on a rotary shaker (250 rpm) at 28°C for 36 hours to give the stage-1 seed. The stage-1 seed (200ml) was inoculated into two 4000-ml baffled flasks,