In the previous paper¹⁾ of this series, ayamycin A complex has been reported to reveal a characteristic cytotoxicity in HeLa cells and to possess an inhibitory activity against Ehrlich ascites carcinoma in mice. As a result of further purification procedures ayamycin A₂ was obtained as needle crystals and its physico-chemical properties were described²⁾.

In this paper the studies on an anti-tumor activity of ayamycin A₂ are presented.