title: Bioavailability of a series of novel acylated ascorbic acid derivatives, 6-O-acyl-2-O-alpha-D-glucopyranosyl-L-ascorbic acids, as an ascorbic acid supplement in rats and guinea pigs.
abstract: The bioavailability of a series of novel acylated ascorbic acid derivatives, 6-O-acyl-2-O-alpha-D-glucopyranosyl-L-ascorbic acids (6-Acyl-AA-2G), as an ascorbic acid (AA) supplement was investigated in rats and guinea pigs. Oral administration of 6-Acyl-AA-2G to rats resulted in an increase in the plasma AA level. However, the intact form was not detectable in the plasma by high-performance liquid chromatography, indicating its hydrolysis through the process of absorption. After an intravenous injection to rats of 6-Octa-AA-2G as a representative derivative, the intact form rapidly disappeared from the plasma, being followed by a prolonged and marked elevation of the plasma AA level. Various tissue homogenates from guinea pigs were examined for their releasing activity of AA, 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G) and 6-O-acyl-AA from 6-Acyl-AA-2G. High activity was observed in the small intestine. These hydrolytic activities to AA and 6-O-acyl-AA were completely inhibited by castanospermine, an alpha-glucosidase inhibitor, and AA-2G was observed as the only resulting hydrolysate, suggesting the participation of alpha-glucosidase and esterase in the in vivo hydrolysis of 6-Acyl-AA-2G. 6-Octa-AA-2G was found to exhibit an obvious therapeutic effect in scorbutic guinea pigs from its repeated oral administration. These results indicate that 6-Acyl-AA-2G is a readily available source of AA activity in vivo, and may be useful as an effective pharmacological agent and as a promising food additive.
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics*; D001206:Ascorbic Acid Deficiency / Q000188:drug therapy / Q000378:metabolism; D001682:Biological Availability; D001921:Brain / Q000378:metabolism; D019587:Dietary Supplements; D004950:Esterases / Q000378:metabolism; D006168:Guinea Pigs; D006868:Hydrolysis; D007421:Intestine, Small / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012614:Scurvy / Q000378:metabolism; D012867:Skin / Q000378:metabolism; D000520:alpha-Glucosidases / Q000378:metabolism
chemical_list: C065378:ascorbic acid 2-O-glucoside; D004950:Esterases; D000520:alpha-Glucosidases; D001205:Ascorbic Acid