Does the Supramolecular Complexation of Polyphenolic Acids with the Isomers of Pyridinecarboxamide Affect Their Antiradical Activity?

Abstract

Polyphenolic compounds are considered one as the most important plant-originated species with antioxidant properties. This paper focuses on exploring the structure and antiradical properties of supramolecular complexes derived from the selected polyphenolic (caffeic and protocatechuic) acids and isomers of pyridinecarboxamide. The chemical interactions between polyphenolic acids and carboxamides were analyzed using FT–IR spectroscopy. The thermal behavior of the solid phases was tested with the help of thermal analysis via thermogravimetry (TG) coupled with differential scanning calorimetry (DSC). The antiradical activity was determined by using the ABTS method (2,2′-azino-bis(3-ehylbenzothiazoline-6-sulfonic acid). The obtained results indicate that the solutions prepared by dissolving the solid materials exhibited better antiradical activity than the binary mixtures prepared by mixing the stock reagents’ solutions. These studies confirmed that supramolecular complexes derived from polyphenolic compounds and N-heterocyclic entities may constitute a quite interesting material for future research.

Keywords

• caffeic acid
• protocatechuic acid
• nicotinamide
• isonicotinamide
• supramolecular complexes
• antioxidant properties