6533b7d0fe1ef96bd125a249

RESEARCH PRODUCT

A full conformational space analysis of bilirubin

Esteban Gabriel Vega HissiSvend J. Knak JensenImre G. CsizmadiaImre G. CsizmadiaF. Tomas-vertMario R. EstradaJuan C. Garro MartinezGraciela Nilda Zamarbide

subject

BilirubinHydrogen bondAb initioCondensed Matter PhysicsSpace (mathematics)BiochemistryTetrapyrrolechemistry.chemical_compoundchemistryComputational chemistrySide chainMoleculePhysical and Theoretical ChemistryConformational isomerism

description

Ab initio methods were utilized in a gas-phase systematic conformational search of bilirubin conformers. The whole molecule was divided into four fragments. Most stable conformers of them were employed to build 196 conformers of the complete bilirubin molecule. Initial geometries were optimized using HF/3-21G level of theory and the minimum energy conformers were then reoptimized at B3LYP/6-31G(d) level. Ridge-tile conformer was the most stable one, in perfect agreement with X-ray data. We found that while tetrapyrrole backbone shows some flexibility, propionic acid side chains have a greater influence in bilirubin conformation because they can interact through different hydrogen bond patterns with the backbone and between them.

yearjournalcountryeditionlanguage
2009-10-01Journal of Molecular Structure: THEOCHEM
https://doi.org/10.1016/j.theochem.2009.06.039