A compound of general formula, or a pharmaceutically acceptable salt, solvate, amide, ester, ether, or N-oxide thereof, for use in combination with another anticancer agent in the treatment of a cancer; wherein R1 is hydrogen, -C R1', substituted or unsubstituted C 1-6 alkyl, substituted or unsubstituted C 2-6 alkenyl, substituted or unsubstituted C 2-6 alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl; R1' is -OH, substituted or unsubstituted C 1-6 alkyl, substituted or unsubstituted C 2-6 alkenyl, substituted or unsubstituted C 2-6 alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl; R2 is substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl; X is -O-, -S-, -CH 2 -, or -NH-; Y is -O-, -S-, -CH 2 -, or -NH-; Z1 is hydrogen, substituted or unsubstituted C 1-6 alkyl, substituted or unsubstituted C 2-6 alkenyl, substituted or unsubstituted C 2-6 alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl; and Z2 is hydrogen, substituted or unsubstituted C 1-6 alkyl, substituted or unsubstituted C 2-6 alkenyl, substituted or unsubstituted C 2-6 alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl; wherein the anticancer agent is selected from the group consisting of type II topoisomerase inhibitors including topoisomerase II poisons and catalytic inhibitors of topoisomerase II, type I topoisomerase inhibitors, Hsp90 inhibitors, proteasome inhibitors, inhibitors of histone deacetylases, protein kinase inhibitors, telomerase inhibitors and microtubule-interfering agents. for use in combination with another anticancer agent in the treatment of a cancer; wherein R1 is hydrogen, -C R1', substituted or unsubstituted C 1-6 alkyl, substituted or unsubstituted C 2-6 alkenyl, substituted or unsubstituted C 2-6 alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl; R1' is -OH, substituted or unsubstituted C 1-6 alkyl, substituted or unsubstituted C 2-6 alkenyl, substituted or unsubstituted C 2-6 alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl; R2 is substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl; X is -O-, -S-, -CH 2 -, or -NH-; Y is -O-, -S-, -CH 2 -, or -NH-; Z1 is hydrogen, substituted or unsubstituted C 1-6 alkyl, substituted or unsubstituted C 2-6 alkenyl, substituted or unsubstituted C 2-6 alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl; and Z2 is hydrogen, substituted or unsubstituted C 1-6 alkyl, substituted or unsubstituted C 2-6 alkenyl, substituted or unsubstituted C 2-6 alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl; wherein the anticancer agent is selected from the group consisting of type II topoisomerase inhibitors including topoisomerase II poisons and catalytic inhibitors of topoisomerase II, type I topoisomerase inhibitors, Hsp90 inhibitors, proteasome inhibitors, inhibitors of histone deacetylases, protein kinase inhibitors, telomerase inhibitors and microtubule-interfering agents.