Akademik Veri Yönetim Sistemi
Journal of Molecular Modeling, cilt.32, sa.1, 2026 (SCI-Expanded, Scopus)
Context: Chelates 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 ML2, where M = Mn+2, Fe+2, Cu+2, Zn+2 and L = MHA, CH3SCH2CH2CH(OH)COO−. Coordination with structural water molecules was taken into account (ML2.nH2O) based on the experimental findings. A comparative analysis was performed with chelates of corresponding amino acid MET in the forms of MLA.nH2O and MA2.nH2O, where A = MET, CH3SCH2CH2CH(NH2)COO−. Formation of dinuclear complexes by binding with the second metal atom was also investigated (M2L2.nH2O). It was found that Cu+2, Fe+2, Zn+2, and Mn+2 form bischelates with both MET and MHA. DFT calculated complexation energy is highest for Cu+2, in which binding contains more covalent contributions, and lowest for Mn+2, in which binding is dominated by electrostatic interactions. A second metal ion might be involved to form dimetallic bischelates of MHA. This is favored by the chelates of Cu+2, Fe+2, and Zn+2. On the other hand, Mn+2 does not tend to form such dimetallic complexes. It was concluded that, in terms of the complexation energies, MHA can be used as a replacement for MET in feed supplements of livestock animals for Cu+2, Fe+2, and Zn+2. On the other hand, for Mn+2, MET might be a better choice in trade-off the antimicrobial properties of MHA. Methods: DFT 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.