Patent ID: 7179834

Claim:
A pharmaceutical composition, comprising an effective amount of a compound having the structure (I) and a pharmaceutically acceptable carrier: wherein R 1 to R 3 are each independently —H, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, substitued heterocyclic, cycloalkyl, substitued cycloalkyl, alkoxy, substituted alkoxy, thioalkyl, substituted thioalkyl, hydroxy, halogen, amino, amido, carboxyl, —C(O)H, acyl, oxyacyl, carbamate, sulfonamide, or sulfuryl, each R 4 is independently alkyl, substitued alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substitued aryl, cycloalkyl, substitued cycloalkyl, E 1 to E 4 are each independently —O, —NR 5 , or —S, wherein R 5 is —H or C 1 –C 6 alkyl, and x is 0 to 8, and further comprising at least one additional anti-neoplastic agent other than the compound having the structure (I).