【Abstract】 The methyl ester terminated G1 5,2 5 and 3 5 poly(amidoamine) dendrimers (PAMAM) are hydrolyzed by using NaOH to obtain external carboxylate groups with them (PAMAMC).These dendrimers show interaction with cytochrome C in some extent.For example,the reduction rate of Fe Ⅲ cytochrome C to Fe Ⅱ cytochrome C by ascorbic acid was clearly slowed down because of the interaction between cytochrome C and PAMAM dendrimers.The reaction happened only betweem Fe Ⅲ cytochrome C and ascorbic acid,it showed a pseudo first order constant of 3 48 min -1 .When PAMAMC (G2 5 or 3 5) dendrimers were added in the reaction system,the pseudo first order constant dropped to 1 40 or 1 32 ?min -1 .The association constant of 1:1 cytochrome C G2 5C is 2 4×10 4 and the association constant of 1:1 cytochrome C G3.5C is 2 6×10 4.更多还原