Piperazinedione compounds

A method for treating tumor, comprising administering to a subject in need thereof an effective amount of the compound having the formula:

• wherein
• A is C(RaRb);
• Z is R3O—(Ar)—B, in which B is C(Rc);
• Ar is pyridyl linked to B at position 2;
• and R3 is H, alkyl substituted with aryl, or aryl;
• in which aryl is unsubstituted or substituted with one or more substitutents selected from the group consisting of halogen, hydroxyl, amino, alkylamino, arylamino, dialkylamino, diarylamino, cyano, nitro, mercapto, carbamido, carbamoyl, carboxyl, thioureido, thiocyanato, sulfonamido, C1˜C6 alkyl, C2˜C6 alkenyl, C1˜C6 alkoxy, and aryl;
• each of R1 and R2, independently, is H, or C(O)Rd;
• and
• one of Ra and Rb is thienyl, furyl, pyridinyl, indolyl, 2-oxo-indolyl, aryl, alkyl, or alkyl substituted with aryl, and each of the other of Ra and Rb, and Rc, and Rd, independently, is H, alkyl, or aryl;
• in which alkyl and aryl are unsubstituted or substituted with one or more substitutents selected from the group consisting of halogen, hydroxyl, amino, alkylamino, arylamino, dialkylamino, diarylamino, cyano, nitro, mercapto, carbamido, carbamoyl, carboxyl, thioureido, thiocyanato, sulfonamido, C1˜-C6 alkyl, C2˜C6 alkenyl, C1˜-C6 alkoxy, and aryl.