Desertomycin: purification and physical-chemical properties.

Desertomycin was isolated from Streptomyces macronensis Dietz sp. nov. UC 8271. Extensive spectroscopic work led us to place desertomycin in the macrocyclic lactone family which contains monazomycin, scopafungin, primycin, azalomycin F4a and niphithricins A and B. The apparent molecular formula was determined by fast atom bombardment mass spectroscopy to be C57H109NO24 (MW = 1,191). Mild acid hydrolysis yielded mannose but contrary to published reports, glutamic acid is not a constituent of desertomycin.