Syntheses and Biological Activities ofN-Alaninylmaleimide and Its Polymers

A new monomer, N-alaninylmaleimide (AMI), was synthesized by the reaction of maleic anhydride and β-alanine. Poly(N-alaninylmaleimide) [poly(AMI)], poly(N-alaninylmaleimide-co-methacrylic acid) [poly-(AMI-co-MA)], and poly(N-alaninylmaleimide-co-vinyl acetate) [poly-(AMI-co-VAc)] were synthesized by photopolymerizations. The synthesized AMI and its polymers were characterized by IR and 1H-NMR spectroscopies, elemental analysis, and gel permeation chromatography (GPC). The average molecular weights as determined by GPC were is follows: M n = 4200, M w = 4300, M w/M n = 1.02 for poly(AMI); M n = 4000, M w = 4100, M w/M n = 1.03 for poly(AMI-co-MA); and M n = 21,500, M w = 23,300, M w/M n = 1.08 for poly(AMI-co-VAc). In-vitro cytotoxicities of polymers against mouse mammary carcinoma (FM-3A/s), mouse leukemia (P-388/s), and human histiocytic lymphoma (U-937/s) cell lines were lower than those of AMI. The in-vivo antitumor activities of polymers against sarcoma 180 cells were greater than those of 5-FU, and the toxicities of polymers were much less than that of 5-FU.