The kineties and mechanism of oxidation of α-alanine by diperiodatocuprate (Ⅲ) ion was studied by spectrophotometry in alkaline medium. The reaction rate showed first order dependance in oxidant and 1.25 order depen...The kineties and mechanism of oxidation of α-alanine by diperiodatocuprate (Ⅲ) ion was studied by spectrophotometry in alkaline medium. The reaction rate showed first order dependance in oxidant and 1.25 order dependance in α-alamne. It was found that the pesudo first-order ([Ala].》 [Cu(Ⅲ)].) rate constant kobs increases with the increases in [OH] and decreases with the increases in [IO]. The hnear relationships between [Ala/kobs and 1/[Ala] and between 1/kobs and [IO] were observed in our experiment. There is a positive salt effect. Under the protection of nitrogen gas, the reaction system can induce polyn1erzation of acrylamide. A plausible mechanism involving free redicals has been proposed. The rate equations derived from the mechanism explained all the experimental results satisfactorily. The rate constant activation paIameters of rate determing step have been calculated.展开更多
ε-聚赖氨酸生产菌株Streptomyces albulus PD-1可合成一种新型非蛋白质氨基酸均聚物聚二氨基丙酸,采用离子交换层析和反向色谱,对聚二氨基丙酸的分离纯化进行研究。离子交换层析柱选用DEAE-Sepharose Fast Flow填料,50 mmol/L磷酸盐缓...ε-聚赖氨酸生产菌株Streptomyces albulus PD-1可合成一种新型非蛋白质氨基酸均聚物聚二氨基丙酸,采用离子交换层析和反向色谱,对聚二氨基丙酸的分离纯化进行研究。离子交换层析柱选用DEAE-Sepharose Fast Flow填料,50 mmol/L磷酸盐缓冲液(p H 7.5)平衡上样,含0.5 mol/L Na Cl的磷酸盐缓冲液(p H 7.5)洗脱,收集洗脱液用分子筛Sephadex G-25除去磷酸盐缓冲液。然后用C18反相色谱进一步纯化,流动相为V(甲醇)/V(0.1%磷酸)=5/95。经过离子交换层析和反向色谱,纯化得到聚二氨基丙酸纯品,回收率为39.8%,样品纯度达98.4%,为后续的聚二氨基丙酸的深入研究奠定基础。展开更多
文摘The kineties and mechanism of oxidation of α-alanine by diperiodatocuprate (Ⅲ) ion was studied by spectrophotometry in alkaline medium. The reaction rate showed first order dependance in oxidant and 1.25 order dependance in α-alamne. It was found that the pesudo first-order ([Ala].》 [Cu(Ⅲ)].) rate constant kobs increases with the increases in [OH] and decreases with the increases in [IO]. The hnear relationships between [Ala/kobs and 1/[Ala] and between 1/kobs and [IO] were observed in our experiment. There is a positive salt effect. Under the protection of nitrogen gas, the reaction system can induce polyn1erzation of acrylamide. A plausible mechanism involving free redicals has been proposed. The rate equations derived from the mechanism explained all the experimental results satisfactorily. The rate constant activation paIameters of rate determing step have been calculated.
文摘ε-聚赖氨酸生产菌株Streptomyces albulus PD-1可合成一种新型非蛋白质氨基酸均聚物聚二氨基丙酸,采用离子交换层析和反向色谱,对聚二氨基丙酸的分离纯化进行研究。离子交换层析柱选用DEAE-Sepharose Fast Flow填料,50 mmol/L磷酸盐缓冲液(p H 7.5)平衡上样,含0.5 mol/L Na Cl的磷酸盐缓冲液(p H 7.5)洗脱,收集洗脱液用分子筛Sephadex G-25除去磷酸盐缓冲液。然后用C18反相色谱进一步纯化,流动相为V(甲醇)/V(0.1%磷酸)=5/95。经过离子交换层析和反向色谱,纯化得到聚二氨基丙酸纯品,回收率为39.8%,样品纯度达98.4%,为后续的聚二氨基丙酸的深入研究奠定基础。
