Estudo de quantificação de compostos fenólicos, avaliação de atividades antioxidantes e modelagem molecular da croton pullei var. Glabrior lanj

Abstract

The study aimed to evaluate, from extracts, the yield (on a dry basis), quantify the total polyphenols, evaluate the antioxidant activity, perform a theoretical NMR research of the julocrotine, crotonimide A and crotonimide B structures, from Croton pullei VAR. glabrior LANJ. and evaluate these molecules in molecular docking against the enzymes Candida albicans (PDB ID: 1AI9), Staphylococcus aureus (PDB ID: 1DIM) and Salmonella thyphimurium (PDB ID: 4URM). A conventional extraction was performed using a stainless-steel extractor and three-factor planning (temperature, particle size and solid/liquid ratio) and three Box-Behnken levels, to determine which variables were influential in the responses. The quantification of total polyphenols was performed according to the Folin-Ciocalteu methodology. For the antioxidant analysis, the IC50 method was applied. And the theoretical NMR study was carried out via DFT, where the computational methods DFT/B3LYP/cc-pvDZ and DFT/B3LYP/6-31 G* were applied to obtain the chemical displacements (δH and δC), to compare to the experimental ones and thus provide which computational method is the most efficient. Yields vary between 5.57 and 10.61. In the quantification of total polyphenols, there was a variation between 101.33 and 308.84 mg EAG/g. The minimum and maximum antioxidant values were 94.74% and 98.97%. In general, the DFT/B3LYP/cc-pvDZ methodology was more efficient compared to the analyzed structures. The molecules showed hydrogen bonds with residues Lys 57 (A), Arg 56 (A), Cys37, Gly38, Asp62, Gly193, Tyr342, Gly56, Arg37, Tyr128, Arg56, Thr58 (A), Gly114 (A) and Thr 127.