Patent ID: 7300954

Claim:
A method for inhibiting the growth of tumor cells in an individual comprising administering to the individual a pharmacologically effective dose of a compound having a structural formula wherein X is oxygen; Y is oxygen, NH or NCH 3 ; R 1 is —(CH 2 ) 1-5 CO 2 H, —(CH 2 ) 7 CO 2 H, —CH 2 CONH 2 , —CH 2 CO 2 CH 3 , —CH 2 CON(CH 2 CO 2 H) 2 , —(CH 2 ) 2 OH, —(CH 2 ) 3 NH 3 Cl, or —(CH 2 ) 2 OSO 3 NHEt 3 ; R 2 and R 3 are independently hydrogen or R 4 ; R 4 is methyl; and R 5 is