Abstract
Several studies have described important biological activities of flavonoids such
as coronary heart disease prevention, hepatoprotective, anti-inflammatory and anticancer
activities, enzyme inhibition activity, and antibacterial, antifungal, and antiviral
activities. Flavonoids show promising activity as natural plant-based antioxidants
due to their antioxidant and free radical scavenging properties. However, their primary
applications as antioxidants in the pharmaceutical, cosmetic, and food industries
are limited because of their moderately hydrophilic nature. Enzymatic acylation of
natural polyphenols with fatty acids or other acyl donors has been suggested for improving
the lipophilic nature of the glycosylated flavonoids. This approach increases flavonoid
solubility and stability in lipophilic systems. Acylation of flavonoids with different
acyl donors may also introduce beneficial properties to the molecule, such as penetration
through the cell membrane and improved antioxidant, antimicrobial, anti-inflammatory,
antiproliferative, cytogenetic, and enzyme inhibition activities. Chemical methods
for the synthesis of flavonoid esters lead to the formation of side products and the
simultaneous decomposition of the flavonoids due to harsh reaction conditions. In
contrast, biocatalytic acylation of flavonoids by lipases offers advantages associated
to the wide availability of these enzymes, their low cost, chemo-, regio-, and enantioselectivity,
mild condition processing and non-requirement of cofactors. This article is focused
on the recent development of lipase-catalyzed synthesis of flavonoid esters and the
impact of the acylation reaction on their biological activities.
Key words
flavonoids - lipase - acylation - biocatalysis
