Enzymatic Acylation of Anthocyanins Isolated from Alpine Bearberry (Arctostaphylos alpina) and Lipophilic Properties, Thermostability, and Antioxidant Capacity of the Derivatives

Abstract

Cyanidin-3- O-galactoside (cy-gal) isolated from alpine bearberry ( Arctostaphylos alpine L.) was enzymatically acylated with saturated fatty acids of different chain lengths with Candida antarctica lipase immobilized on acrylic resin (Novozyme 435). The acylation reaction was optimized by considering the reaction medium, acyl donor, substrate molar ratio, reaction temperature, and reaction time. The highest conversion yield of 73% was obtained by reacting cy-gal with lauric acid (molar ratio of 1:10) in tert-butanol at 60 °C for 72 h. A novel compound was synthesized, which was identified as cyanidin-3- O-(6″-dodecanoyl)galactoside by mass spectrometry and nuclear magnetic resonance. Introducing lauric acid into cy-gal significantly improved both the lipophilicity and thermostability and substantially preserved the ultraviolet-visible absorbance and antioxidant properties. The research provides important insight in expanding the application of natural anthocyanins in the cosmetic and food industries.

Enzymatic acylation of rutin with benzoic acid ester and lipophilic, antiradical, and antiproliferative properties of the acylated derivatives

“…This may be explained by excess acyl donors which resulted in shifting of the thermodynamic equilibrium to promote the synthesis of acylated derivatives. Our results were consistent with several studies on enzymatic acylation of flavonoids (e.g., isoorientin, isovitexin, and fluorofuran) with different acyl donors (Chebil et al., 2006; Ma et al., 2012; Yang et al., 2018).…”

Novozym 435: the “perfect” lipase immobilized biocatalyst?

“…Different chain length saturated fatty acids were used to acylate cyanidin-3-O-galactoside using N435, with the best results obtained using lauric acid. 343 The product was identified as cyanidin-3-O-(6″-dodecanoyl)galactoside.…”

Kinetics of Enzymatic Synthesis of Cyanidin-3-Glucoside Lauryl Ester and Its Physicochemical Property and Proliferative Effect on Intestinal Probiotics

“…The enzymatic reaction yielded only a monoester and its regioselectivity was constant, showing that acylation always took place on the primary hydroxyl group present on the glycoside moiety of the molecule (C6ʹʹ-OH). The location of the acylated site has been well documented in previous studies for a range of acyl donors [ 24 , 26 ]. This was confirmed by comparing downfield and upfield shifts between Cy3glc and the Cy3glc-C12 in the same solvent.…”

“…The lipophilicity of Cy3glc from black rice and its acylated derivate Cy3glc-C12 were evaluated by the octanol-water partition coefficient (log P) following the methods described previously [24].…”