| 摘要 |
The present invention provides compounds according to formula I: and pharmaceutically acceptable salts thereof. For compounds of formula I, R1 and R2 are independently selected from the group consisting of H, —C(═O)—(CH2)2-aryl, and —C(═O)—(CH2)n—C(═O)—NH-aryl. The subscript n is from 2 to 6. R3 is selected from the group consisting of H and —C(═O)—O—R4; and R4 is selected from the group consisting of alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, arylalkyl, substituted arylalkyl, cycloheteroalkyl, substituted cycloheteroalkyl, heteroalkyl and substituted heteroalkyl. Compounds are provided wherein at least one of R1 and R2 is other than H. Pharmaceutical compositions, methods for inhibiting the growth of cancer cells, and methods for the treatment of cancer are also provided. |
