PROCESS FOR PRODUCING NEW ANTIBIOTIC BBM-1675C AND D WITH ANTITUMOR EFFECT AND PHARMACEUTICAL COMPOSITIONS COMPRISING SAME

摘要

Antibiotics BBM-1675C (Ia) and BBM-1675D (Ib) are new and are characterised by their physicochemical properties. - (Ia) and (Ib) are both hydrolysis prods. of BBM-1675A1 and BBM-1675A2 (esperamicin A1 and A2; see GB2141425), with (Ia) being formed first and (Ib) being formed by further hydrolysis of (Ia). The molecular wts. of (Ia) and (Ib) are 855 and 695 respectively.