Using 80% vol aqueous DMSO as the reaction medium for transesterification of an RNA model substrate 2-hydroxypropyl 4-nitrophenyl phosphate allows one to observe catalysis in buffer mixtures composed of highly basic components such as guanidines, amidines or alkylamines, which provide up to 103-fold accelerations over the background reaction in the 0.01–0.1 M concentration range. The rate law kobs= k1 [B]+ k2 [B][BH+] was established ...
