47494-29-1Relevant academic research and scientific papers
Making thiamin work faster: Acid-promoted separation of carbon dioxide
Hu, Qingyan,Kluger, Ronald
, p. 12242 - 12243 (2005)
The conjugate of thiamin and benzoylformate, mandelylthiamin (MTh), undergoes decarboxylation about 106 times slower than the analogous enzymic intermediate. It has now been discovered that the decarboxylation of MTh is accelerated by the acid component of pyridine and 4-picoline buffers. There is no role for a proton donor to stabilize the transition state for decarboxylation: catalysis must be achieved by the acid's trapping the product carbanion, preventing recarboxylation. This requires that diffusion of CO2 is rate-determining, and that protonation of the carbanion allows this to occur. This interpretation correctly predicts that the same acid components will prevent a fragmentation reaction by protonating the intermediate, which fragments only as the conjugate base. Copyright
Accelerating unimolecular decarboxylation by preassociated acid catalysis in thiamin-derived intermediates: Implicating Bronsted acids as carbanion traps in enzymes
Kluger, Ronald,Ikeda, Glenn,Hu, Qingyan,Cao, Pengpeng,Drewry, Joel
, p. 15856 - 15864 (2006)
Mandelylthiamin (MT) is formally the conjugate of thiamin and benzoylformate. It is the simplified analogue of the first covalent intermediate in benzoylformate decarboxylase. Although MT is the functional equivalent of the enzymic intermediate, it is 10
