Mono[6-(2-mercaptoethylamino)-6-deoxy]-β-cyclodextrin as an efficient glyoxalase mimic

Abstract

Trifunctional mono[6-(2-mercaptoethylamino)-6-deoxy]-β-cyclodextrin (MACD) has been prepared and used as a glyoxalase model. When 2-naphthylglyoxal (NAGO) is employed as a diagnostic substrate, MACD shows an overall activity greater than the reference compound 2-(dimethyl-amino)ethanethiol (DAET) at around pH 9; MACD favours remarkably the preequilibrium α-keto hemithioacetal formation, but slightly decelerates the follow-up rearrangement. The pH and kinetic isotope effects on the rate have revealed the mechanistic difference between the MACD- and DAET-promoted reactions.