Esterase activity of cyclodextrin dithiocarbamates

The catalytic activity of dithiocarbamate appended α- and β-cyclodextrins in the hydrolysis of p-nitrophenyl acetate (PNPA) was studied at alkaline pH. The values of kcat/kuncat for the hydrolysis of PNPA ranged from 8 to 165 in the presence of the catalyst and are pH independent in the range 7.5–9.0. Addition of Cu(II) increases the activity by factors of 75–515 and kcat values increase with increasing pH in the same range. The differences in the obtained kinetic parameters are interpreted on the basis of two different mechanisms.