Hydrosoluble Antioxidants by Enzymatic Glucosylation of a Vitamin E Derivative Using Marine α-d-Glucosidase from Aplysia fasciata

Abstract

Relevant examples of polyglycosylating exo-glycosidases were reported among enzymes of marine origin (Aplysia fasciata, Geobacillus, and Pecten maximus). Herein we describe the enzymatic polyglucosylation of a chromane-methanol (2-hydroxymethyl-2,5,7,8-tetramethylchroman-6-ol) performed by using the α-D-glucosidase from the sea hare Aplysia fasciata. New di-, tri-, and tetrasaccharide derivatives were synthesized and their antioxidant activities were evaluated by DPPH test. High enzymatic substrate conversion was assessed by NMR spectroscopy, and the products were easily purified. These findings suggest that the proposed procedure is an effective process both for the molecular diversity of products and for the peculiar stereochemistry of the enzyme. At the beginning of the enzymatic reaction, only (S)-diastereomer of the monoglucoside was obtained. The isomaltoside was the most abundant disaccharide obtained and showed a radical scavenging activity similar to that of the chromane-methanol. The disaccharide can be considered a new hydrosoluble antioxidant agent useful for various technological applications (cosmetics, food industry, etc.). A relationship between the interglycosidic linkage present in disaccharides and trisaccharides and their scavenging activity was also pointed out.