RIBOFURANOSE-CONTAINING POLYMERS - SYNTHESIS AND CATALYTIC ACTIVITY FOR THE HYDROLYSIS OF PHOSPHODIESTER AND THE CLEAVAGE OF DNA

Two derivatives of 5-deoxy-D-erythro-pent-4-enofuranose (4 and Gland 6 -deoxy-alpha-D-galacto-hex-5-enopyranose (9) were synthesized. Copolym erization of these monomers with maleic anhydride and subsequent react ions resulted in (5-deoxy-D-erythro-pent-4-enofuranose)-alt-(maleic ac id)] (11) and its derivatives, such as dimethyl ester (12), 2,3-O-isop ropylidene (13), 1-O-methyl (15), and eoxy-alpha-D-galacto-hex-5-enopy ranose)-alt-maleic acid)](17). Polymers 11, 12, and 15 showed catalyti c activity for the hydrolysis of phosphodiesters. The rate constant (k (cat)) for the hydrolysis of ethyl p-nitrophenyl phosphate substrate c atalyzed by polymer 12 was 9.0 x 10(-1) h(-1) at 50 degrees C, corresp onding to a rate acceleration of about 10(3) as compared with that of the uncatalyzed reaction (9.1 x 10(-4) h(-1)). Competitive and noncomp etitive inhibitions for this catalysis were observed on addition of so dium acetate (K-I = 5.9 x 10(-4) M) and K2HPO4 (K-I = 2.5 x 10(-4) M), respectively. The polymers also catalyzed the cleavage of ssDNA of 30 bases and tetradeoxyadenylic acid in Tris buffer (pH 7.4) at ionic st rength 0.02 (KCl) at 37 degrees C. The catalytic activity of the polym ers seemed to be attributable to vic-cis-diol groups of furanose rings on the polymer backbones.