Combining Laccase-Mediated Dimerization of Resveratrol and Centrifugal Partition Chromatography: Optimization of E-Labruscol Production and Identification of New Resveratrol Dimers

Abstract

Resveratrol dimers are of great interest for pharmaceutical and cosmetic applications. Nevertheless, the yield of their bioproduction is limited by both the competition between the possible radical−radical coupling pathways and complex isolation procedures. Alternative organic synthesis methods do not afford higher yields. Although enzymatic routes can provide dimers in one step from resveratrol, biocatalysis optimization is required to improve yields and orient radical−radical coupling selectivity toward a specific resveratrol dimer, E-labruscol herein. After a rapid study of the relative importance of the biocatalysis parameters, a design of experiments was implemented to produce E-labruscol in high yield by laccase-mediated dimerization of resveratrol. E-labruscol and δ-viniferin were identified and isolated by flash chromatography as major products in 21 and 52% yields, respectively. As an alternative to purification on silica gel, efficient separation of the aforementioned compounds was achieved by centrifugal partition chromatography (CPC). This technology provided δ-viniferin in 63.1% yield (90% purity) and labruscol isomers in 20.4% yield with a purity of 95% after a CPC polishing step, but it also revealed the presence of E-labruscol diastereomers, leachianol F and leachianol G, as major reaction products, as well as less abundant products: pallidol, Z-labruscol, ε-viniferin, and two new resveratrol dimers named iso-δ-viniferin and iso-ε-viniferin.

Study of phenoxy radical couplings using the enzymatic secretome of Botrytis cinerea

“…It should be noted that, in addition to C-8 dimerisation products, other compounds can be obtained, such as trans -ε-viniferin, iso- trans -ε-viniferin or iso- trans -δ-viniferin described by Sursin et al (2023) . However, these compounds are obtained in low yields ( Sursin et al, 2023 ).…”

“…It should be noted that, in addition to C-8 dimerisation products, other compounds can be obtained, such as trans -ε-viniferin, iso- trans -ε-viniferin or iso- trans -δ-viniferin described by Sursin et al (2023) . However, these compounds are obtained in low yields ( Sursin et al, 2023 ). In the case of iso- trans -ε-viniferin, the authors proposed a possible mechanism involving a dismutation of the radical species leading to cationic forms ( Sursin et al, 2023 ).…”

“…However, these compounds are obtained in low yields ( Sursin et al, 2023 ). In the case of iso- trans -ε-viniferin, the authors proposed a possible mechanism involving a dismutation of the radical species leading to cationic forms ( Sursin et al, 2023 ).…”