Substituted analoguss of camptothecin possessing cytotoxic activity towards cancer cells, of the general structure: STR1 wherein E is H, CO2 R, CONH2, CONHR, CONR2, acyl, or CN; X is H OH, or OR; R1, R2, R3, and R4 are independently the same or different and are H, or a linear or branched chain alkyl, alkylaryl, or hydroxyalkyl group, or an aryl group; R5, R6, R7, R8, and R9 are independently the same or different and are H, or a linear or branched chain alkyl, alkylaryl, alkoxy, hydroxyalkyl, or aminoalkoxy group, or an aryl or aryloxy group, or a C-glycal, or CO2 R, nitro, cyano, Cl, F, Br, I, SR10, NR11 R12, or OR13 ; R is H, or a linear or branched chain alkyl, alkylaryl, or hydroxyalkyl group, or an aryl group; R10, R11 and R12 are independently the same or different and are H, or a linear or branched chain alkyl, alkylaryl, hydroxyalkyl, or acyl group, or an aryl group; R13 is glycosyl; n is 0 or 1; with the proviso that when R 1 is ethyl, and n is 0, E, R2, R3, and R4 are not all H. Intermediate compounds leading to the camptothecin analogues comprise substituted tricyclic compounds which consist of rings C, D, and E fused together. Methods for preparing the analoguss involve condensation of such intermediates with variably substituted protected α-aminobenzaldehydes.