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Syntheses of dopa glycosides using glucosidases

Ramaiah, Sivakumar and Thangavel, Ponrasu and Soundar, Divakar (2008) Syntheses of dopa glycosides using glucosidases. Glycoconjugate Journal, 26. pp. 33-39. ISSN 0282-0080

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Abstract

Syntheses of L-dopa 1a glucoside 10a,b and DLdopa 1b glycosides 10–18 with D-glucose 2, D-galactose 3, D-mannose 4, D-fructose 5, D-arabinose 6, lactose 7, Dsorbitol 8 and D-mannitol 9 were carried out using amyloglucosidase from Rhizopus mold, β-glucosidase isolated from sweet almond and immobilized β-glucosidase. Invariably, L-dopa and DL-dopa gave low to good yields of glycosides 10–18 at 12–49% range and only mono glycosylated products were detected through glycosylation/arylation at the third or fourth OH positions of L-dopa 1a and DL-dopa 1b. Amyloglucosidase showed selectivity with D-mannose 4 to give 4-O-C1β and D-sorbitol 8 to give 4-O-C6-O-arylated product. β-Glucosidase exhibited selectivity with D-mannose 4 to give 4-O-C1β and lactose 7 to give 4-O-C1β product. Immobilized β-glucosidase did not show any selectivity. Antioxidant and angiotensin converting enzyme inhibition (ACE) activities of the glycosides were evaluated glycosides, out of which L-3-hydroxy-4-O-(β-D-galactopyranosyl- (1′→4)β-D-glucopyranosyl) phenylalanine 16 at 0.9± 0.05 mM and DL-3-hydroxy-4-O-(β-D-glucopyranosyl) phenylalanine 11b,c at 0.98±0.05 mM showed the best IC50 values for antioxidant activity and DL-3-hydroxy-4-O-(6-Dsorbitol) phenylalanine 17 at 0.56±0.03 mM, L-dopa-Dglucoside 10a,b at 1.1±0.06 mM and DL-3-hydroxy-4-O- (D-glucopyranosyl)phenylalanine 11a-d at 1.2±0.06 mM exhibited the best IC50 values for ACE inhibition.

Item Type: Article
Uncontrolled Keywords: Arylation . L-dopa . L-Dopa Glucosides . DL-Dopa . DL-Dopa Glycosides . Glycosylation . Glucosidases . Regioselectivity
Subjects: 600 Technology > 08 Food technology > 16 Nutritive value > 05 Enzymes
Divisions: Fermentation Technology and Bioengineering
Depositing User: Food Sci. & Technol. Information Services
Date Deposited: 02 Jan 2009 10:15
Last Modified: 23 Nov 2017 04:27
URI: http://ir.cftri.com/id/eprint/8863

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