Biosynthesis of Ascorbic Acid

Abstract

SOME time ago¹, we observed that incubation of some tissues of the rat with mannose in a mixture of Ringer-Locke solution and phosphate buffer at pH 7.4 resulted in an increase of the ascorbic acid value, as determined by the usual titrimetic technique with 2: 6-dichlorophenol indophenol². The experiments in vitro were supported by experiments in vivo, in which it was shown that the injection of mannose into the rat also caused an increase in the ascorbic acid content of some of its tissues³. Cell-free extracts were also obtained from germinating Phaseolus mungo, which were likewise capable of converting mannose into ascorbic acid⁴.