, 2009) and antioxidant activity of kaempferol (Park, Rho, Kim, & Chang, 2006), besides improving the bioavailability of hesperidin (Nielsen et al., 2006) and of flavonoid glycosides in fruit juices and green tea (Gonzáles-Barrio et al., 2004). The use of enzymes to modify the structure and improve the physicochemical and biological properties of flavonoids has been of great scientific and industrial

interest due to their wide availability, high selectivity, low cost and their promotion of efficient reactions with few by-products. α-l-Rhamnosidases [E. C. 3.2.1.40] are glycosyl hydrolases which cleave terminal α-l-rhamnose from natural glycosides. Only two commercial preparations of α-l-rhamnosidases (naringinase and hesperidinase) are available, and both are SCH 900776 chemical structure from fungal sources. Hesperidinase is obtained from species of Penicillium and Aspergillus Y-27632 mouse niger and naringinase is obtained from Penicillium decumbens. All these preparations

also show significant β-d-glucosidase activity that catalyzes the hydrolysis of terminal non-reducing residues with glucose release ( Yadav, Yadav, & Yadav, 2010). Thus the activity of the α-l-rhamnosidases in the rutin substrate produces two derivatives: quercetin-3-glucoside (isoquercetrin) and quercetin, in proportions that depend on the reaction conditions. Although there is a structural similarity to rutin, quercetin-3-glucoside and quercetin, there are some noticeable differences in physical, chemical

and biological properties. Quercetin glycosides show higher solubility in water than quercetin due to the hydrophilicity of the sugar moieties (Aherne & ÓBrien, 2002). In comparison with rutin and quercetin, quercetin-3-glucoside is better absorbed, suggesting that conjugation with glucose enhances quercetin absorption in small intestine (Arts, Sesink, Faassen-Peters, & Hollman, 2004). Indeed, previous reports have shown that quercetin-3-glucoside has a more potent antiproliferative effect than quercetin Amoxicillin or rutin (You, Ahn, & Ji, 2010). Thus, the synthesis of mono-glycosylated quercetin from rutin by the enzymatic hydrolysis method seems to be a good alternative for obtaining compounds with enhanced functional properties. Hesperidinase or naringinase with inactivated β-d-glucosidase activity and expressing α-l-rhamnosidase activity allow the production of very expensive flavonoid glycosides, quercetin-3-glucoside, in an easy and cheap bioprocess starting from rutin. In the present work, the enzymatic hydrolysis of rutin by two commercial heat-treated glycosyl hydrolases (hesperidinase and naringinase) was investigated in order to obtain partially hydrolyzed rutin with enhanced functional properties.