Ii. Bioavailability and in Vivo Formation of Aa-2g

I . INTRODUCTION It is well known that L-ascorbic acid (AsA) has multifarious functions in our body. Humans who are unable to synthesize AsA in vivo have to absorb it as an essential nutrient from foods and some supplements. However, AsA is easily oxidized by oxygen in aqueous solutions, followed by oxidative degradation. To improve such instability, some derivatives including monoor di-substituted AsA have been synthesized chemically. Recently, we have found a new AsA conjugate which is effectively synthesized by enzymatic transglucosylation. This compound is characterized by its high stability in aqueous solutions and its non-reducibility. Since enzymatic process surpasses chemical process with regard to its selectivity, efficiency and cost, the stable AsA glucoside has a bright prospect of developing the new field of applications as AsA supplements. In this paper we describe its enzymatic formation, property, bioavailability and biological activity.