Angiotensin-converting enzyme inhibitory and antioxidant activities of enzymatically synthesized phenolic and vitamin glycosides

Amyloglucosidase from Rhizopus mould and β-glucosidase
from sweet almond were employed for the preparation
of phenolic and vitamin glycosides of vanillin, Nvanillylnonanamide,
DL-dopa, dopamine, curcumin, atocopherol
(vitamin E), pyridoxine (vitamin B6),
ergocalciferol (vitamin D2), thiamin (vitamin B,) and
riboflavin (vitamin B2). 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 IC50 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 ICS0 value for ACE inhibition were observed
for I l-0-(D-fructofur-anosyl)thiamin (0.52 ± 0.03 mM), 3-
hydroxy-4-0-(6-D-sorbitol)phenylalanine (0.56 ± 0.03 mM),
4-0-(β-D-glucopyranosyl)vanillin (0.61 ± 0.03 mM), 4-0-(Dgal-
actopyranosyl)vanillin (0.61 ±0.03 mM) and pyridoxine-
D-glucoside (0.84 ± 0.04 mM). Similarly, best IC50, values
for antioxidant activity were observed for 1,7-0-(bis-β-Dglucopyranosyl)
curcumin (0.8 ± 0.04 mM), 4-0-(β-Dglucopyranosyl)
vanillin (0.9 ±0.05 mM), 3-hydroxy-4-0-(β-
D-galactopyranosyl-(l’—►4)β-D-glucopyranosyl)
phenylalanine (0.9 ± 0.05 mM), 20-O-(Dglucopyranosyl)
ergocalciferol (0.9 ± 0.05 mM) and
dopamine-D-galactoside (0.93 ± 0.05 mM).