1980 Volume 33 Issue 11 Pages 1256-1261
Micromonospora chalcea subsp. izumensis produces a novel β-lactamase inhibitor izumenolide (EM4615). Isolation of izumenolide was performed by extraction into butanol under acidic conditions and then back extraction into water at neutrality. The compound was precipitated from the aqueous phase by the addition of calcium or barium salts. Further purification was achieved by distribution in BuOH-1N NaOH. Izumenolide is a macrolide containing sulfate ester groups.