Estudos DFT e NBO voltados para o potencial antioxidante dos curcuminoides da curcuma longa

Abstract

For many years, saffron (Curcuma longa L) has been used as a medicinal plant, as it has antioxidant, anti-inflammatory, antibacterial, anticarnogenic properties, among others. Three polyphenol molecules highlight: curcumin (CUR), demethoxycurcumin (DMC) and bisdemethoxycurcumin (BDMC), and only the first is widely studied because it demonstrates large amounts in the plant's rhizome. Our research laboratory, the LQCM/UFTM, discovered that Curcuma longa L. from the cerrado region of Minas Gerais in Uberaba has a higher amount of BDMC and DMC and started studies in order to better distinguish the molecular properties that are related to the antioxidant activity of these three curcuminoids. The DFT method was used from the functional M06-2X with base functions 6- 311++(2d,p) Analyzes of their radical and deprotonated forms were carried out, each molecule was submitted to vacuum, water (polar medium) and ethanoate of ethyl (apolar medium). The results found for the CUR showed good agreement with other studies and methodologies. BDMC showed great similarity with CUR, with some differentiated characteristics, such as a greater charge transfer capacity, according to the NBO electronic delocalization study, greater solubility in water, but similar in ethyl ethanoate, used as a model of non-polar solvent to emulate phospholipid vesicles or cell membranes. This way, BDMC demonstrated different characteristics from CUR that can be explored in the administration of medical treatments.