The influence of rat and frog liver enzymes on the hydrolysis of ortho and pyrophosphoric esters of thiamine

Homogenates of rat and frog liver were incubated with ThDP and ThMP at different pHs. The products of hydrolysis were identified by paper chromatography. In experiments carried out at pH 9 with ThDP as substrate in the presence of rat liver, the spot corresponding to Th did not appear on the chromatogram. This was in contrast with parallel experiments with frog liver. ThMP from commercial source behaved differently toward enzymatic decomposition than ThMP originating from hydrolysis of ThDP. Attempts have been made to explain these differences.