The present invention provides compounds useful to inhibit tumor growth and to induce apoptosis. In general, the anti-cancer agents (ACA) are described by the formula: [ACA].sub.n-X[Formula I] wherein X is a linker group having 2 5 functional groups or is absent, n=1, and ACA is selected from the group consisting of Formula II, Formula III, Formula IV, Formula V, and Formula VI, as described herein. Other compounds described herein are defined by the Formula VII, as described herein.