申请人:PURDUE RESEARCH FOUNDATION
                            
                            
                                公开号:WO2001004130A1
                            
                            
                                公开(公告)日:2001-01-18
                            
                            The invention provides a compound of formula (I): wherein R1, Ra, Rb, Rc, and Rd have any of the values defined in the specification, as well as pharmaceutical compositions comprising such compounds or salts. The compounds are useful for treating cancer in animals.