Study on structural detailing of gossypetin and its medicinal application in UV filtering, radical scavenging, and metal chelation open up through NCI, TD-DFT, QTAIM, ELF, and LOL analysis

Abstract

Density functional theory (DFT) computations were used to investigate gossypetin’s antioxidant effects via •OH, •OOH, and •NO2 scavenging and Zn2+ chelation mechanisms in solvent phases. Intramolecular hydrogen bonding, which accounts for the stability of generated radicals, was explained using non-covalent interaction (NCI) analysis. Investigations have been done on three primary operating mechanisms, sequential proton loss electron transfer (SPLET), single electron transfer-proton transfer (SET-PT), and H-atom transfer (HAT). SPLET was found to be the most advantageous for •OOH, HAT for •NO2, and HAT in polar whereas SPLET in non-polar media for •OH. UV absorption in the region 200–400 nm suggests, gossypetin can act as a UV filter and the nature of excitation was described by hole-electron analysis. The interaction energy analysis predicted the best chelation site in gossypetin. The bond critical point (BCP) analysis explained the electrostatic nature of donor–acceptor interaction. The influence of explicit solvent effects is also taken into account.