Effect of B-Vitamins on Biosynthesis of Ascorbic Acid from Glucose Cycloacetoacetate in Germinating Phaseolus Radiatus.

Summary The anti-vitamins, i.e. pantoyltaurine and pyrithiamine, inhibited ascorbic acid biosynthesis from acetoacetate and glucose in germinating mung beans indicating a blocking of the condensation reaction of acetoacetate with glucose to form GCA. The corresponding vitamins reversed the inhibition by antivitamins. That pyrithiamine and pantoyl-taurine inhibited synthesis of ascorbic acid in presence of GCA, and the corresponding vitamins reversed the inhibition. Cocarboxylase and CoA, of which thiamine and pantothenic acids are the constituents, are involved in both the condensation reaction of glucose with acetoacetate to form GCA and in the further metabolism of GCA to ascorbic acid.