Chemical properties of polyphenols: A review focused on anti-inflammatory and anti-viral medical application

Abstract

Polyphenols are attributed to multiple biological activities that provide nutritional and therapeutical benefits. The present paper is a descriptive review focused on polyphenolic chemical structural aspects contributing to explain biological and biochemical functions offered by these phytochemicals. Element conformation differences, ring modifications, the presence of specific functional groups, and the tridimensional chemical arrangement are fundamental to explain specific effects presented by polyphenols. The anti-oxidant and anti-inflammatory actions of polyphenols suggest that basic chemical reactions and element re-organization are important in understanding their function, well-known polyphenols such as quercetin, curcumin, and catechin have been evaluated in multiple studies. Moreover, anti-bacterial and anti-viral activities have been proven to be dependent on hydroxylation, methoxylation, and alkylation of several polyphenol ring components. Polyphenols extracted from tea, like catechins, proved to inhibit efficiently hepatitis C, Zika, and Chikungunya viruses. They have also acted as promising prophylactic and therapeutic agents against SARS-CoV-2. Epicatechin extracted from the hawthorn tree showed antiviral activity on several bacteria such as Escherichia coli and Salmonella typhimurium. The inclusion of these natural components in daily diets is of primary nutritional benefit and importance in the prevention of several diseases.