The isolation of barium and calcium diketo-l-gulonates and the biological significance of 2:3-diketo-l-gulonic acid

Abstract

Ba and Ca salts of 2:3 diketo-l-gulonic acid from solns. of mutarotated dehydroascorbic acid have been isolated in 60 and 50% yields respectively and characterized. On a diet in which a daily dose of 0.5 mg. of l-ascorbic acid gave a high degree of protection against scurvey, the Ca salt showed no antiscorbutic activity for guinea pigs in daily doses equivalent to 0.5 mg. of 2:3 diketo-1-gulonic acid or in 20 mg. doses. The latter quantity upon reduction with H2S yielded an indophenol reducing compound corresponding to 0.5 mg. of 1-ascorbic acid. l-Ascorbic acid was regenerated from Ba diketogulonate by reduction with HI.