Proactive antitumor compounds

摘要

The present invention features proactive antitumor compounds of the following formula: wherein R1 is COOZ; Z being H, alkali metal, alkaline earth metal, an ammonium group which is optionally substituted with one or more alkyl groups, or a carboxyl protecting group; each of R2, R3, and R4, independently, is OH or ORa; Ra being a hydroxyl protecting group; X is benzene or pyridine, optionally substituted with Rb; Rb being H, C1-5 alkyl, C1-5 alkoxy, NO2, F, Cl, Br, SO3H, and CN; R5 is H or OH; and each of n and m, independently, is 0 or 1; or a salt thereof.