To study the coordination reactions of glucosamine and α-aminoacid with copper(Ⅱ) under the physiological condition,the pH potentiometric titration was used to determine the protonation constants of glucosamine and ...To study the coordination reactions of glucosamine and α-aminoacid with copper(Ⅱ) under the physiological condition,the pH potentiometric titration was used to determine the protonation constants of glucosamine and α-aminoacid,and the formation constants of the binary and ternary complexes of glucosamine and α-aminoacid with Cu(Ⅱ) at 37℃ with ionic strength I=0.154mol/L NaCl respectively.The results indicated that all of the protonation constants of glucosamine and α-aminoacid,and stability constant of the binary and ternary complexes of glucosamine and α-aminoacid with Cu(Ⅱ) at 37℃,I=0.154mol/L NaCl are smaller than those at 25℃ with ionic strength I=0.10 mol/L KNO3 respectively.The results also indicated that the stable ternary complex could be formed from glucosamine and α-aminoacid with copper(Ⅱ).Furthermore,the two biologically active ligand,glucosamine and α-aminoacid showed higher compatible.The stability of the ternary complexes increased with the increase of protonation constant of α-aminoacid and the stability of its binary complexes.展开更多
文摘To study the coordination reactions of glucosamine and α-aminoacid with copper(Ⅱ) under the physiological condition,the pH potentiometric titration was used to determine the protonation constants of glucosamine and α-aminoacid,and the formation constants of the binary and ternary complexes of glucosamine and α-aminoacid with Cu(Ⅱ) at 37℃ with ionic strength I=0.154mol/L NaCl respectively.The results indicated that all of the protonation constants of glucosamine and α-aminoacid,and stability constant of the binary and ternary complexes of glucosamine and α-aminoacid with Cu(Ⅱ) at 37℃,I=0.154mol/L NaCl are smaller than those at 25℃ with ionic strength I=0.10 mol/L KNO3 respectively.The results also indicated that the stable ternary complex could be formed from glucosamine and α-aminoacid with copper(Ⅱ).Furthermore,the two biologically active ligand,glucosamine and α-aminoacid showed higher compatible.The stability of the ternary complexes increased with the increase of protonation constant of α-aminoacid and the stability of its binary complexes.