Essential amino acids interacting with flavonoids: A theoretical approach

The interaction of two flavonoid species (resorcinolic and fluoroglucinolic) with the 20 essential amino acids was studied by the multiple minima hypersurface (MMH) procedures, through the AM1 and PM3 semiempirical methods. Remarkable thermodynamic data related to the properties of the molecular association of these compounds were obtained, which will be of great utility for future investigations concerning the interaction of flavonoids with proteins. These results are compared with experimental and classical force field results reported in the available literature, and new evidences and criteria are shown. The hydrophilic amino acids demonstrated high affinity in the interaction with flavonoid molecules; the complexes with lysine are especially extremely stable. An affinity order for the interaction of both flavonoid species with the essential amino acids is suggested. Our theoretical results are compared with experimental evidence on flavonoid interactions with proteins of biomedical interest. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005