Sonochemical enzyme-catalyzed regioselective acylation of flavonoid glycosides

• Acylated derivatives of isoquercitrin and phloridzin can be synthesized using lipases.
• Ultrasonication enhances the acylation reaction time by 4–5 folds.
• Sonication with stirring is more efficient than conventional acylation of flavonoids.

This work compares a highly efficient and alternative method of sonication-assisted lipase catalyzed acylation of quercetin-3-O-glucoside and phloretin-2′-glucoside, using Candida antarctica lipase B (Novozyme 435®), with a range of fatty acids. In this study, sonication-assisted irradiation coupled with stirring has been found to be more efficient and economical than conventional reaction conditions. Sonication-assisted acylation accelerated the reactions and reduced the time required by 4–5 folds.

This investigation describes the efficacy of ultrasound-assisted esterification coupled with stirring over the conventional method of biocatalytic synthesis of twenty (20) different fatty acids acylated derivatives of phloridzin and isoquercitrin. (i) Immobilized lipase B, from Candida antarctica (Novozyme 435®), 3 Å molecular sieves, ultrasonication, acetone, 40–45 °C, 2.5–3 h; R = butyric, octanoic, dodecanoic, palmitic, oleic, stearic, linoleic, linolenic, eicosapentaenoic, docosahexaenoic acids or their corresponding esters.Figure optionsDownload as PowerPoint slide