A new anthracycline antibiotic micromonomycin from Micromonospora sp.

In the course of our continuing search for novel antimicrobial agents,1-5) we have isolated a novel antibacterial anthracycline, micromonomycin (1), from culture Micromonospora sp. Micromonomycin was identified as a new anthracycline using high resolution ESIMS and extensive NMR spectroscopic analyses. In this paper, we describe the isolation and structure elucidation of 1. The biological activity of 1 against Gram-positive and Gram-negative bacterial strains as well as fungal pathogens is also reported. The germination and fermentation conditions of this culture were described previously.5) The fermentation broth (2 liters) was stirred with 100g of NaCl and 4 liters of acetonitrile (MeCN). The organic layer was separated and dried in vacuum. The extract was absorbed onto the polymeric resin, CG161 (-100ml) and the NaCl salt was washed out with water (200ml). The absorbed organic material was eluted with 200ml 40% aq. MeCN, and 80% aq. MeCN to yield 432 and 73mg of dried material, respectively, after removing solvent in vacuo. The organic material of 80% McCN fraction was fractionated on an