Intramolecular acyl migration and enzymatic hydrolysis of a novel monoacylated ascorbic acid derivative, 6-O-dodecanoyl-2-O-alpha-d-glucopyranosyl-L-ascorbic acid.
A stable ascorbic acid derivative, 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G), exhibits vitamin C activity in vitro and in vivo after enzymatic hydrolysis to ascorbic acid. AA-2G has been approved by the Japanese Government as a quasi-drug principal ingredient in skin care and as a food additive. In order to achieve efficient action as an ascorbic acid source, a pro-vitamin C agent, on a variety of cells or tissues, we have synthesized a series of monoacyl AA-2G derivatives. Our previous studies indicate that a series of the derivatives is a readily available source of AA activity in vitro and in vivo, and suggested that intramolecular acyl migration of the derivatives might have occurred in a neutral aqueous solution. In this study, intramolecular acyl migration and enzymatic hydrolysis of a monoacyl AA-2G derivative, 6-O-dodecanoyl-2-O-alpha-D-glucopyranosyl-L-ascorbic acid (6-sDode-AA-2G), were investigated. 6-sDode-AA-2G underwent an intramolecular acyl migration to yield ca. 10% of an isomer in neutral aqueous solutions, and the acyl-migrated isomer was isolated and characterized as 5-O-dodecanoyl-2-O-alpha-D-glucopyranosyl-L-ascorbic acid (5-sDode-AA-2G). In some tissue homogenates from guinea pigs as well as in neutral aqueous solutions, 6-sDode-AA-2G underwent partial acyl migration to give 5-sDode-AA-2G. 6-sDode-AA-2G and the resulting 5-sDode-AA-2G were predominantly hydrolyzed with esterase to AA-2G and then with alpha-glucosidase to ascorbic acid in the tissue homogenates. The results will provide a further basis for its use as an ingredient in skin care, as an effective pharmacological agent and as a promising food additive.
Tai
Akihiro
A
Faculty of Life and Environmental Sciences, Prefectural University of Hiroshima, Shobara, Hiroshima 727-0023, Japan. atai@pu-hiroshima.ac.jp
Mori
Tasuku
T
Urushihara
Masaya
M
Ito
Hideyuki
H
Kawasaki
Daisuke
D
Yamamoto
Itaru
I
D000818:Animals; D001205:Ascorbic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism*; D004950:Esterases / Q000378:metabolism; D006168:Guinea Pigs; D006868:Hydrolysis; D008297:Male; D000520:alpha-Glucosidases / Q000378:metabolism
C065378:ascorbic acid 2-O-glucoside; D004950:Esterases; D000520:alpha-Glucosidases; D001205:Ascorbic Acid