1995 Volume 48 Issue 8 Pages 787-792
A new antibiotic, ripostatin, was isolated from the culture supernatant of the myxobacterium, Sorangium cellulosum strain So ce377. It is a macrocyclic lactone carbonic acid containing an unsubstituted phenyl ring in a side chain. The antibiotic acts especially on Staphylococcus aureus, but seems not to penetrate most bacteria.
The MIC values are in the range of 1 μg/ml. Ripostatin is an inhibitor of eubacterial RNA polymerase. It interferes with the initiation of RNA synthesis.