Research Information System
III. International Enzyme and Bioprocess Days, Tokat, Turkey, 9 - 11 September 2022, pp.1
Flavonoids are important natural products with various biological
activities such as anticancer, antiviral, antioxidant, anti-inflammatory and
antimicrobial effects. Similarly, halogenated molecules occupy a significant
portion of drugs on the market or in the development pipeline for
pharmaceutical industry. Nevertheless, halogenated natural products are quite rare
in nature. Currently, chemical halogenation is the common approach for the
generation of halogenated drug molecules, which exhibit improved biological
activities and enhanced pharmacokinetic properties. For instance, compared to
chrysin and other tested flavonoids, halogenated chrysins have indicated
stronger antiviral activity against dengue and Zika viruses. While chemical
halogenation is limited by its poor selectivity and harsh reaction conditions, enzymatic
halogenation represents a green and effective method to prepare halogenated
compounds. In this study, we conducted the biotransformation of various flavonoids
in engineered Escherichia coli
BL21(DE3) expressing fungal flavin-dependent halogenase (Rdc2). We successfully
halogenated chrysin, quercetin, naringenin, apigenin and hesperetin to yield a
series of halogenated flavonoids. The halogenated flavonoids were purified and characterized
with LC-MS and NMR. This work not only offers a green method for the
halogenation of natural products, particularly flavonoids, but also expands the
chemical repertoire of natural products by generating novel halogenated
compounds.