Synthesis and biological activities of copolymers of N‐glycinyl maleimide with methacrylic acid and vinyl acetate

Copolymerizations of N‐glycinylmaleimide (GMI) with methacrylic acid (MA) and vinyl acetate (VAc) were carried out in 2‐butanone using lauroylperoxide as an initiator at 70°C. Synthesized GMI, poly(GMI‐co‐MA), and poly(GMI‐co‐VAc) were characterized by IR and 1H‐NMR spectroscopies, elemental analysis, and gel permeation chromatography. The in vitro cytotoxicities of poly(GMI‐co‐MA) and poly(GMI‐co‐VAc) were evaluated using K‐562 human leukemia cells and HeLa cells. From the cytotoxicity data against HeLa cells, the copolymers are less cytotoxic than monomeric GMI at dosage of 0.02, 1.0, and 5.0 mg/mL. Copolymers were very effective at any dosage tested. The in vivo antitumor activities of poly(GMI‐co‐MA) and poly(GMI‐co‐VAc) were also evaluated against mice bearing sarcoma 180. Monomeric GMI and its copolymers showed higher antitumor activity than 5‐fluorouracil (5‐FU) at any dosage tested.