Regioselective lipase-catalyzed synthesis of 3-o-acyl derivatives of resveratrol and study of their antioxidant properties.
One of the approaches to increasing the bioavailability of resveratrol is to protect its 3-OH phenolic group. In this work, regioselective acylation of resveratrol at 3-OH was achieved by transesterification with vinyl acetate catalyzed by immobilized lipase from Alcaligenes sp. (lipase QLG). The maximum yield of 3-O-acetylresveratrol was approximately 75%, as the lipase also catalyzes its further acetylation affording the diester 3,4'-di-O-acetylresveratrol and finally the peracetylated derivative. Long saturated and unsaturated fatty acid vinyl esters were also effective as acyl donors with similar regioselectivity. In contrast, lipase B from Candida antarctica catalyzes the acylation of the phenolic group 4'-OH with 80% yield and negligible formation of higher esters. The analysis of the antioxidant properties showed that the Trolox equivalent antioxidant capability (TEAC) values for the acetyl and stearoyl derivatives at 3-OH were, respectively, 40% and 25% referred to resveratrol. The addition of an acyl chain in the 3-OH position caused a higher loss of activity compared with that at the 4'-OH.
Torres
Pamela
P
Instituto de Catálisis y Petroleoquímica, CSIC, Cantoblanco, Marie Curie 2, 28049 Madrid, Spain.
Poveda
Ana
A
Jimenez-Barbero
Jesús
J
Ballesteros
Antonio
A
Plou
Francisco J
FJ
D000421:Alcaligenes / Q000201:enzymology; D000975:Antioxidants / Q000138:chemical synthesis / Q000737:chemistry*; D001426:Bacterial Proteins / Q000737:chemistry*; D004800:Enzymes, Immobilized / Q000737:chemistry; D005656:Fungal Proteins; D007700:Kinetics; D008049:Lipase / Q000737:chemistry*; D000077185:Resveratrol; D013267:Stilbenes / Q000138:chemical synthesis / Q000737:chemistry*; D013379:Substrate Specificity
D000975:Antioxidants; D001426:Bacterial Proteins; D004800:Enzymes, Immobilized; D005656:Fungal Proteins; D013267:Stilbenes; D008049:Lipase; C431349:lipase B, Candida antarctica; D000077185:Resveratrol