– Antibiotic MA 144M2 is an anthracycline glycoside that inhibits the growth of gram-positive bacteria, e.g. Staphyococcus aureaus, Bacillus subtilis and Sarcina lutea, and inhibits the growth of animal tumors such as leukemia L 1210, P 388 and sarcoma 180. It’s produced by fermentation of MA 144-producing strains of streptomyces and by the chemical or enzymatic conversion of aclacinomycin A or cinerubin A.