Topoisomerase I selective cytotoxic sugar derivatives of indolopyrrolocarbazoles

A compound of formula I

• 78
• having a topoisomerase I selectivity index of greater than about 100;
• its enantiomers, diastereomers, pharmaceutically acceptable salts, hydrates, prodrugs and solvates thereof;
• wherein Ra and Rb are independently selected from the group consisting of H and O, provided that when O is selected Ra and Rb are taken together to form O;
• Ra′ and Rb′ are independently selected from the group consisting of H and O, provided that when O is selected Ra′ and Rb′ are taken together to form O;
• X1, X1′, X2 and X2′ are each independently selected from the group consisting of F, Br and H;
• Q is selected from the group consisting of NH, S and O;
• and R is a substituted hexose group.