Patent ID: 7687487

Claim:
A lactone-stable, “flipped” E-ring camptothecin analog consisting of the structure illustrated below: wherein; X is —(CH 2 ) n —; wherein n≦2 or CF 2 ; R 1 is —(CH 2 ) n —, —(CH 2 ) n Si(R 5 ) 3 , —(CH 2 ) n Ge(R 5 ) 3 ; wherein n=0 to 6; any halide; any short chain amine; and wherein R 5 is CH 3 , C 2 H 5 , C 3 H 8 ; R 2 is —(CH 2 ) n —, —(CH 2 ) n Si(R 5 ) 3 , —(CH 2 ) n Ge(R 5 ) 3 ; wherein n=0 to 6; any halide; any short chain amine; and wherein R 5 is CH 3 , C 2 H 5 , C 3 H 8 ; R 3 and R 4 are any halide; any short chain amine; CH 3 O; —OCH 2 CH 2 O—, —OCH 2 O—; or a pharmaceutically-acceptable salt thereof.