Novel antitumor L-arabinose derivative of indolocarbazole with high affinity to DNA.

Novel indolocarbazole derivative 12-(alpha-L-arabinopyranosyl)indolo[2,3-alpha]pyrrolo[3,4-c]carbazole-5,7-dione (AIC) demonstrated high potency (at submicromolar concentrations) against the NCI panel of human tumor cell lines and transplanted tumors in vivo. In search of tentative targets for AIC, we found that the drug formed high affinity intercalative complexes with d(AT)(20), d(GC)(20) and calf thymus DNA (binding constants (1.6x10(6)) M(-1)< or =K(a)< or =(3.