Partricin, a heptaene macrolide antibiotic, has been separated into three polyene components, partricins A, B and C, and one non-polyene component by countercurrent distribution. Treatment of partricin with base gave p-(methylamino)acetophenone and p-aminoacetophenone from partricins A and B, respectively, identifying both as members of the aromatic subgroup of the heptaene antibiotics. Both partricins A and B yield mycosamine on mild acid hydrolysis. NMR and mass spectral studies on products of ozonolysis or hydrogenolysis of acetyl derivatives provided evidence for the partial structures 1 approximately 9.