Electronic structure analysis of riboflavin: OVGF and EOM-CCSD study

Area of Science:

• Computational Chemistry
• Biochemistry
• Quantum Chemistry

Background:

• Vitamin B2 (riboflavin) is crucial for various biological processes.
• Understanding its electronic structure is key to elucidating its biological activity.
• Computational methods offer insights into molecular properties and interactions.

Purpose of the Study:

• To computationally simulate the photoelectron spectrum of riboflavin in the gas phase.
• To determine the relative stability and abundance of different riboflavin conformers.
• To investigate the relationship between riboflavin's electronic structure and its biological function.

Main Methods:

• Conformational search using molecular mechanics (AMMP potential).
• Boltzmann population weighting (BPW) for conformer abundance.
• High-level Equation-of-Motion Coupled-Cluster (EOM-IP-CCSD) for ionization energies.
• Natural Bonding Orbital (NBO) and Molecular Electrostatic Potential (MEP) for electron density analysis.

Main Results:

• Identified eight riboflavin conformers and determined the relative stability and abundance of the three most stable ones.
• Calculated valence ionization energies (IP) using EOM-IP-CCSD.
• Characterized ionization processes and orbital electron densities using NBO and MEP methods.
• Observed that reduced ionization energies of outermost orbitals correlate with increased availability for ligand-receptor bonding.

Conclusions:

• The electronic structure of riboflavin, particularly the ionization energies of its outermost orbitals, influences its biological activity.
• Computational simulations provide valuable insights into the molecular mechanisms of riboflavin's function.
• This study establishes a link between riboflavin's electronic properties and its role in ligand-receptor interactions.