Lectin derivatives of methotrexate and chlorambucil as chemotherapeutic agents.

Methotrexate and chlorambucil, each covalently linked to either abrus agglutinin, abrin, ricinus agglutinin, ricin, or concanavalin A, were prepared. A single dose of the derivative injected ip into sarcoma 180-bearing noninbred N:NIH(S) white mice resulted in prolongation of the survival time and was more effective than an equivalent dose of free drug and lectin. Drug-lectin also showed a higher inhibitory effect on the DNA biosynthesis of the tumor cell than did an equivalent dose of the free drug and lectin.