The present invention provides a novel ascorbic acid derivative as a
provitamin C with improved stability in the body and prolonged life in
the body compared to conventionally known 2-O-(.alpha.-D-glucopyranosyl)a-
scorbic acid. The composition comprising the novel compound
2-.beta.-(-D-glucopyranosyl)ascorbic acid has been extracted from plants
such as from Ningxia Lycium barbarum L. and/or Lycium chinense Mill. The
compositions comprising 2-O-(.beta.-D-glucopyranosyl)ascorbic acid may be
enzymatically synthesized using .beta.-D-glucosyltransferase. Pure
2-O-(.beta.-D-glucopyranosyl)ascorbic acid may be produced from such
compositions. Alternatively, 2-O-(.beta.-D-glucopyranosyl)ascorbic acid
may be produced by chemical synthesis. The 2-O-(.beta.-D-glucopyranosyl)a-
scorbic acid results in higher stability and a prolonged life of vitamin C
when ingested in the body compared to the corresponding
.alpha.-D-glucopyranosyl derivative, and is therefore highly suitable as
a provitamin C to be used in cosmetics and foods.
