Selective Synthesis of 3-O-Palmitoyl-Silybin, a New-to-Nature Flavonolignan with Increased Protective Action against Oxidative Damages in Lipophilic Media
Samantha Drouet,
Joël Doussot,
Laurine Garros,
David Mathiron,
Solène Bassard,
Alain Favre-Réguillon,
Roland Molinié,
Éric Lainé,
Christophe Hano
Affiliations
Samantha Drouet
Laboratoire de Biologie des Ligneux et des Grandes Cultures, INRA USC1328, Université d’Orléans, 45067 Orléans, France
Joël Doussot
Laboratoire de Biologie des Ligneux et des Grandes Cultures, INRA USC1328, Université d’Orléans, 45067 Orléans, France
Laurine Garros
Laboratoire de Biologie des Ligneux et des Grandes Cultures, INRA USC1328, Université d’Orléans, 45067 Orléans, France
David Mathiron
Plateforme Analytique, Institut de Chimie de Picardie FR 3085 CNRS, Université de Picardie Jules Verne, 33 rue St Leu, 80039 Amiens, France
Solène Bassard
BIOPI EA3900, Biologie des Plantes et Innovation, Université de Picardie Jules Verne, 80037 Amiens, France
Alain Favre-Réguillon
Département Chimie Vivant Santé (EPN 7), Conservatoire National des Arts et Métiers, 75141 Paris CEDEX 03, France
Roland Molinié
BIOPI EA3900, Biologie des Plantes et Innovation, Université de Picardie Jules Verne, 80037 Amiens, France
Éric Lainé
Laboratoire de Biologie des Ligneux et des Grandes Cultures, INRA USC1328, Université d’Orléans, 45067 Orléans, France
Christophe Hano
Laboratoire de Biologie des Ligneux et des Grandes Cultures, INRA USC1328, Université d’Orléans, 45067 Orléans, France
A selective acylation protocol using cerium chloride (CeCl3) as catalyst was applied to functionalize silybinin (1), a natural antioxidant flavonolignan from milk thistle fruit, in order to increase its solubility in lipophilic media while retaining its strong antioxidant activity. The selective esterification of 1 at the position 3-OH with a palmitate acyl chain leading to the formation of the 3-O-palmitoyl-silybin (2) was confirmed by both mass spectroscopy (MS) and nuclear magnetic resonance (NMR) analyses. The antioxidant activity of 1 was at least retained and even increased with the CUPRAC assay designed to estimate the antioxidant activity of both hydrophilic and lipophilic compounds. Finally, the 3-O-palmitoylation of 1, resulting in the formation of 2, also increased its anti-lipoperoxidant activity (i.e., inhibition of conjugated diene production) in two different lipophilic media (bulk oil and o/w emulsion) subjected to accelerated storage test.
