Modeling the chelation of methionine hydroxy analogue D,L-2-hydroxy-4(methylthio) butanoic acid with Mn

contextChelates of transition metal ions with amino acids and peptides are widely used in animal feeding. Methionine hydroxy analogue (MHA) was proposed as a replacement for amino acid methionine (MET) to solve stability problems within such applications and to provide extra anti-microbial benefits. In this study, chelation patterns of MHA with transition metal ions are investigated computationally. Bischelates are modeled as ML

methodsDFT was used to model the chelate structures at the wB97-XD/6-31+G(d,p) level of theory. Gaussian 16 program was used for geometry optimizations. All molecules and chelates were optimized in aqueous environment to mimic the experimental conditions using the Polarizable Continuum Model (PCM) implemented in Gaussian program. Explicit water molecules were added to investigate the structural coordination. Electron density topology analyses within Quantum Theory of Atoms-in-Molecules (QTAIM) have been employed to reveal the nature of bonding interactions. AIMAll software package was used to analyze the electron density and topological critical points involved in chelation. Charge transfer was analyzed by NPA charges on metal ions. NCI Analysis was performed to understand the nature of non-covalent interactions better using Multiwfn and VPN softwares.