铝与L-谷氨酸和α-酮戊二酸相互作用的电位滴定分析  

Potentiometric Studies of Aluminum Ⅲ Interaction with L-Glutamate and α-Ketoglutarate in Acidic Aqueous Solutions

作　　者：杨小弟[1] 毕树平[1] 王先龙[1] 刘剑[1] 

机构地区：[1]南京大学化学系配位化学国家重点实验室,南京210093

出　　处：《分析化学》2003年第12期1454-1457,共4页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金 (No .2 0 0 75 0 11);教育部优秀青年教师奖励计划基金资助项目

摘　　要：采用电位滴定对酸性溶液中Al α 酮戊二酸和Al L 谷氨酸反应体系的形态分布进行了分析 ,获得如下结论 :(1 )Al3+ 与α 酮戊二酸在酸性溶液中配位形成 1∶1 [AlLH2 + ,AlL+ ,AlLH- 1 ]和 1∶2 [AlL-2 ,AlL2 H3-- 2 ]的单核形态以及 2∶1 [Al2 L4 + ]的双核形态 ;(2 )Al3+ 与L 谷氨酸在酸性溶液中配位形成 1∶1 [AlAH2 + ,AlA+ ,AlAH- 1 ]的单核形态以及 2∶1 [Al2 A4 + ]的双核形态 ;(3 )Al3+ 与L 谷氨酸在酸性溶液中配位能力比α 酮戊二酸要弱 ,与辅酶NAD+ 相当。同时 ,Al3+ 与α 酮戊二酸的配位能力虽然比Fe3+ ,Cu2 + 弱 ,但要比Ca2 + ,Mg2 + 强得多。The complexations of α-ketoglutaric acid (α-KG) and L -glutamic acid (Glu) with Al 3+ in acidic aqueous solution were studied with pH-metric titrations. It leads the following results: (1) In an acidic aqueous solution, α-KG binds Al 3+ in a bidentate manner to form 1∶1 species (AlLH 2+ , AlL +, AlLH_ -1 ), 1∶2 species (AlL -_2, AlL_2H 3- _ -2 ) and 2∶1 species (Al_2L 4+ ) at the carboxyl and carbonyl moieties. (2) In an acidic aqueous solution, L -Glu complex with Al 3+ to form 1∶1 species (AlLH 2+ , AlL +, AlLH_ -1 ) and 2∶1 species (Al_2L 4+ ) through the carboxyl groups. (3) The complex ability of Al-Glu is weaker than that of Al-α-KG, and almost the same as that of Al-NAD + (nicotinamide adenin dinucleotide) in the same concentration aqueous solutions. Also, the sequences of the metal ions complex with α-KG activities are: Fe 3+ >Cu 2+ >Al 3+ >Ni 2+ , Ca 2+ , Mg 2+ , Sr 2+ and Zn 2+ . These results may help to further understand the influences of Al on enzyme reactions in biological system.

关 键 词：铝 L—谷氨酸 α—酮戊二酸 相互作用 电位滴定分析 酸性溶液 配位化合物 形态 生物化学 

分 类 号：O657.1[理学—分析化学]