Novel approach for flavonoid esters production: statistically optimized enzymatic synthesis using natural oils and application in cosmetics

The present work describes application of natural triglycerides for lipase-catalyzed esterification of structurally diverse flavonoids – esculin, naringin and phloridzin. Ester mixtures with laurate, linolenate or linoleate as prevailing products were obtained in reactions with coconut, linseed and sunflower oil, respectively. By using response surface methodology, influence of key experimental factors – reaction time, substrates and enzyme concentrations for transesterification of esculin with linseed oil was investigated. High molar conversion (78.5%), product yield (19.13 mg/ml) and specific yield (2.83 mmol/genzyme) were achieved at optimized conditions. Determined optimums were successfully applied in esculin transesterification with other two oils. Furthermore, esculin esters mixtures were incorporated in gel emulsions, and their effect on transepidermal water loss (TEWL) as well as skin sensitivity was examined. Obtained results have shown significant hydration effect and good dermatological compat...