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Enzymatic syntheses of water-soluble alpha-tocopheryl glycosides were carried out in di-isopropyl ether using amyloglucosidase from Rhizopus mold or beta-glucosidase isolated from sweet almond. Optimum conditions for the amyloglucosidase were: alpha-tocopherol 0.5 mmol, D-glucose 0.5 mmol, 400 activity unit (AU) amyloglucosidase, 0.2 mM pH 7 phosphate buffer and 72 h; and for the beta-glucosidase: alpha-tocopherol 0.5 mmol, D: -glucose 0.5 mmol, 110 AU beta-glucosidase, 0.1 mM pH 6 phosphate buffer and 72 h. Out of 11 carbohydrates employed, amyloglucosidase reacted only with D-glucose to give 50% of 6-O-(alpha-D-glucopyranosyl)alpha-tocopherol. However, the beta-glucosidase gave 6-O-(beta-D-glucopyranosyl)alpha-tocopherol, 6-O-(alpha-D-galactopyranosyl)alpha-tocopherol, 6-O-(beta-D-galactopyranosyl)alpha-tocopherol, 6-O-(alpha-D-mannopyranosyl)alpha-tocopherol and 6-O-(beta-D-mannopyranosyl)alpha-tocopherol in yields ranging from 10-25%. Water solubility of 6-O-(alpha-D-glucopyranosyl)alpha-tocopherol was 26 g/l at 25 degrees C. alpha-Tocopheryl glycosides showed antioxidant activities with IC(50) values from 0.5 to 1 mM and angiotensin-converting enzyme (ACE) inhibitory activity with IC(50) values from 1.3 to 2.6 mM.

Amyloglucosidase from Rhizopus mould and beta-glucosidase from sweet almond were employed for the preparation of phenolic and vitamin glycosides of vanillin, N-vanillylnonanamide, DL-dopa, dopamine, curcumin, alpha-tocopherol (vitamin E), pyridoxine (vitamin B(6)), ergocalciferol (vitamin D(2)), thiamin (vitamin B(1)) and riboflavin (vitamin B(2)). Approx. 20 enzymatically prepared phenolic and vitamin glycosides were subjected to ACE (angiotensin-converting enzyme) inhibition activity measurements, and 14 glycosides were tested for antioxidant activities. Both phenolic and vitamin glycosides exhibited IC(50) values for ACE inhibition in the 0.52+/-0.03-3.33+/-0.17 mM range and antioxidant activities ranging from 0.8+/-0.04 to 1.18+/-0.06 mM. Comparable ACE inhibition values were observed between free phenols and vitamin glycosides. However, antioxidant activities of glycosides were, in general, lesser than those of free phenols. Best IC(50) value for ACE inhibition were observed for 11-O-(D-fructofuranosyl)thiamin (0.52+/-0.03 mM), 3-hydroxy-4-O-(6-D-sorbitol)phenylalanine (0.56+/-0.03 mM), 4-O-(beta-D-glucopyranosyl)vanillin (0.61+/-0.03 mM), 4-O-(D-galactopyranosyl)vanillin (0.61+/-0.03 mM) and pyridoxine-D-glucoside (0.84+/-0.04 mM). Similarly, best IC(50) values for antioxidant activity were observed for 1,7-O-(bis-beta-D-glucopyranosyl)curcumin (0.8+/-0.04 mM), 4-O-(beta-D-glucopyranosyl)vanillin (0.9+/-0.05 mM), 3-hydroxy-4-O-(beta-D-galactopyranosyl-(1'-->4)beta-D-glucopyranosyl)phenylalanine (0.9+/-0.05 mM), 20-O-(D-glucopyranosyl)ergocalciferol (0.9+/-0.05 mM) and dopamine-D-galactoside (0.93+/-0.05 mM).

beta-Glucosidase isolated from sweet almond catalyzed syntheses of water soluble retinol glycosides were carried out in SCCO(2) media with carbohydrates-D-glucose 2, D-galactose 3, D-mannose 4, D-fructose 5, and D-sorbitol 6. Retinol glycosides yields were in the 9-34% range. Reaction with D-fructose 5 gave a highest yield of 34%. Excellent regioselectivity was observed with D-mannose 4 and D-sorbitol 6 which gave exclusively C1beta-mannoside and C1-D-sorbitolide.

Enzymatic syntheses of pyridoxine glycosides were carried out in di-isopropyl ether organic medium using beta-glucosidase isolated from sweet almond. Optimum conditions determined for the reaction with D-glucose were 40% (w/w D-glucose) beta-glucosidase at 0.18 mM (1.8 ml) of pH 5 acetate buffer over a 72 h incubation period. Of 11 carbohydrates employed, beta-glucosidase gave 7-O-(alpha-D-glucopyranosyl)pyridoxine 5a, 7-O-(beta-D-glucopyranosyl)pyridoxine 5b, 6-O-(alpha-D-glucopyranosyl)pyridoxine 5c, 7-O-(alpha-D-galactopyranosyl)pyridoxine 6a, 7-O-(beta-D-galactopyranosyl)pyridoxine 6b, 6-O-(alpha-D-galactopyranosyl)pyridoxine 6c, 7-O-(alpha-D-mannopyranosyl)pyridoxine 7a, 7-O-(beta-D-mannopyranosyl)pyridoxine 7b, and 6-O-(alpha-D-mannopyranosyl)pyridoxine 7c in yields ranging from 23 to 40%.