A displacement test based on the interaction between the flavonoid quercetin and an excess of metal chloride allows the determination of the binding constant for the reaction between quercetin and Ca2+,Mg^2+and Ni^2+.The values obtained were 2.20±1.77×10^3 for Ca^2+,1.37±0.59×10^3 for Mg^2+and 7.03±1.04×10^4 for Ni^2+,and all interactions showed type 1:1 stoichiometry,as determined by titration and by the method of continuous variations(Job’s method).The complexion effect was observed qualitatively through a colorimetric change in the medium(yellow→neon yellow)and spectroscopically through a bathochromic shift in the absorption band of quercetin in the presence of metals.This investigation serves as a tool for the development and testing of materials capable of capturing toxic metal ions or favoring the absorption of beneficial ions(in relation to the human metabolism)through the construction of efficient bioorganic systems.The results reported herein allow understanding of this detection system,indicating the following ascending order of the binding constants(Mg^2+展开▼
机译:A Sanskrit-Chinese Collation Study of the Larger Sukhāvatīvyūha Sūtra Grammar under the Framework of Chinese Historical Linguistics—A Case of the Chinese Translations of Sanskrit Instrumental, Ablative and Locative Nouns =汉语历史语言学框架中的《无量寿经》语法梵汉对勘研究——以梵语名词工
机译:High-resolution structural studies of ultra-thin magnetic, transition metal overlayers and two-dimensional transition metal oxides using synchrotron radiation