Novel triazole based pyrophosphate analogues of thiamine pyrophosphate (TPP) have been synthesised and tested for inhibition of pyruvate decarboxylase (PDC) from Zymomonas mobilis. The thiazolium ring of thiamine was replaced by a triazole in an efficient two-step procedure. Pyrophosphorylation then gave extremely potent triazole inhibitors with KI values down to 20 pM, compared to a KD value of 0.35 uM for TPP. This triazole scaffold was used for further investigation and six analogues containing mimics of the pyrophosphate group were synthesised and tested for inhibition of PDC. Several effective analogues were found with KI values down to around 1 nM.
Department of Chemistry
University of Cambridge