Investigation on electronic structure, vibrational spectra, NBO analysis, and molecular docking studies of aflatoxins and selected emerging mycotoxins against wild-type androgen receptor

Abstract

The geometry, frontier molecular orbitals (FMOs), vibrational, NBO analysis, and molecular docking simulations of aflatoxins (B1, B2, M1, M2, G1, G2), zearalenone (ZEA) emodin (EMO), alternariol (AOH), alternariol monoethyl ether (AMME), and tenuazonic acid (TeA) mycotoxins have been extensively theoretically studied and discussed based on quantum density functional theory calculations using Gaussian 16 software package. The theoretical computation for the geometry optimization, NBOs, and the molecular docking interaction was conducted using Density Functional Theory with B3LYP/6-31+G(d,p), NBO program, and AutoDock Vina tools respectively. Charge delocalization patterns and second-order perturbation energies of the most interacting natural bond orbitals (NBOs) of these mycotoxins have also been computed and predicted. Interestingly, among the mycotoxins investigated, aflatoxin G1 is seen to give the strongest stabilization energy while Zearalenone shows the highest tendency to accept electron(s) and emodin, an emerging mycotoxin gave the best binding pose within the androgen receptor pocket with a mean binding affinity of -7.40 kcal/mol.

DFT, ADMET and Molecular Docking Investigations for the Antimicrobial Activity of 6,6′-Diamino-1,1′,3,3′-tetramethyl-5,5′-(4-chlorobenzylidene)bis[pyrimidine-2,4(1H,3H)-dione]

“…In NBO analysis, all possible interactions between “filled” (donor) Lewis-type NBOs and “empty” (acceptor) non-Lewis NBOs were examined, and their corresponding energetic significance was estimated by second-order perturbation theory. As these interactions donate occupancy from the idealized Lewis structure’s localized NBOs into the empty non-Lewis orbitals (and thus, to departures from the idealized Lewis structure description), they are identified as “delocalization” corrections to the zeroth-order natural Lewis structure [ 39 ]. The stabilization energy E (2) attributed to delocalization (“2e-stabilization”) i → j is estimated for each donor NBO () and acceptor NBO ( j ) as where q i is the donor orbital occupancy, ε i , ε j are diagonal elements (orbital energies), and F ( i , j ) is the off-diagonal NBO Fock matrix element.…”

Designing Novel Compounds for the Treatment and Management of RET-Positive Non-Small Cell Lung Cancer—Fragment Based Drug Design Strategy

“…Similarly, the ionization potential (IP) and electron affinity (EA) of the selected compounds were determined during the analysis. The other global descriptors hardness (η), softness (S) and chemical potential (χ, −µ) were calculated using the below equations to determine the reactivity and stability of the compound [ 31 , 32 ]: …”

Experimental, DFT study, and in silico molecular docking investigations of dichlorodiphenyltrichloroethane against human estrogen receptor alpha

“…The larger perturbation energy value also called the stabilization energy value E (2) depicts a stronger interaction between electron donors and electron acceptors, i.e., the greater extent of conjugation of the whole system and the more donating tendency from the electron donors to electron acceptor was vividly understood by this analysis. NBO analysis of the studied structure has been performed by using the DFT/B3LYP/6-311+G(d) level of theory (Agwupuye et al, 2021c) to understand clearly the charge transfer or conjugative interaction, delocalization of electron density in the molecule and energy of interaction as reported in Tab. 3.…”