二氢杨梅素分子结构与性质的密度泛函理论研究.

In this paper, the molecular geometry of dihydromyricetin was optimized based on density flooding theory (DFT)using B3LYP flooding combined with 6-31G group, based on which the active sites of dihydromyricetin molecules were calculated using water as solvent and the infrared spectra was analyzed. The electrostatic potential results showed that the nucleophilic active site of dihydromyricetin is located near the phenolic hydroxyl atom (H23) ; while the electrophilic active site is located in and near the oxygen atom (O32) . The results of frontline molecular orbital studies indicate that the highest occupied orbitals (HOMO) of dihydromyricetin molecules are located near ketone oxygen (O32)and hydroxyl oxygen (O20), indicating that these sites are susceptible to reaction with electrophilic reagents. And the lowest occupied orbitals (LUMO) are located in the carbon atom (C12, C13, C14) region, indicating that these regions can react with nucleophilic reagents. The results of the simplified Fukui function (f) confirm that the electrophilic activity of the f-value of the oxygen atom reagents. The results of the simplified Fukui function (f) confirm that the electrophilic activity of the f-value of the oxygen atom located in the C-O-C bond is larger than those of the oxygen atom in other sites; while the f+ value of the carbon atom located in C8 is larger, so the nucleophilic activity is stronger in this site. The infrared spectral data of dihydromyricetin obtained by theoretical calculations do not differ much from those obtained experimentally, which indicates that the theoretical calculations may be reliable. Thus, it provides some theoretical reference for the experimental and theoretical studies of the relationship between the structure and properties of dihydromyricetin. [ABSTRACT FROM AUTHOR]