Studies on the active metabolite (DU-86) of KW-2189, a novel derivative of duocarmycin

Some derivatives of DU-86 as an active metabolite of KW-2189, which is a novel duocarmycin derivative, have been synthesized and evaluated for the biological activity. The results suggested that the methylation of aromatic NH moiety showed extremely decreased anticellular and antitumor activity, demonstrating that the free NH moiety play an important role in the biological activity.