Thiol Reactivity and Its Impact on the Ciliate Toxicity of α,β-Unsaturated Aldehydes, Ketones, and Esters
Thiol Reactivity and Its Impact on the Ciliate Toxicity of α,β-Unsaturated Aldehydes, Ketones, and Esters
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DOI：
10.1021/tx100226n
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发表时间：
2010-12-01
影响因子：
4.1
通讯作者：
Schuurmann, Gerrit
中科院分区：
文献类型：
--
作者：
Bohme, Alexander;Thaens, Diana;Schuurmann, Gerrit
A recently introduced chemoassay has been used to determine second order rate constants of the electrophile-nucleophile reaction of 15 alpha beta unsaturated aldehydes with glutathione The respective k(GSH) values vary for more than 3 orders of magnitude and are within the range determined previously for 31 alpha beta unsaturated ketones and esters Structure-reactivity analyses yield distinct relationships between k(GSH) and structural features of the compounds Moreover increasing k(GSH) increases the aldehyde toxicity toward ciliates in terms of 48 h EC50 values (effective concentration yielding 50% growth inhibition of Tetrahymena pyriformis within 48 h) A respective log-log regression equation including both k(GSH) and the octanol/water partition coefficient K-ow yields a squared correlation coefficient of 0 96 Comparative analysis with corresponding data for 15 ketones and 16 esters reveals systematic differences between the three compound classes with regard to the individual contributions of hydrophobicity and electrophilic reactivity to aquatic toxicity The former is particularly pronounced for aldehydes while the ester toxicity is largely governed by reactivity with ketones showing an intermediate pattern that is more similar to the one of esters than of aldehydes It follows that within the Michael acceptor domain of alpha beta unsaturated carbonyls a distinction between aldehydes and nonaldehydic derivatives appears necessary when employing electrophilic reactivity as a component for the quantitative prediction of their reactive toxicity toward aquatic organisms
