Conformation of Symmetric Bilirubin Analogs from ¹³C-Nuclear Magnetic Resonance Spin Lattice T₁ Relaxation Times

Abstract

Symmetric analogs of bilirubin with propionic acid groups shortened and lengthened (and esterified as methyl esters) adopt similar conformations in deuterated dimethylsulfoxide solvent, as determined from their ¹³C-NMR spin lattice relaxation times. Segmental motion of the alkanoic acid chain carbons indicates internal hydrogen bonding with solvent participation.

Key Words:

• (n = 1-5) Mesobilirubin XIIIα
• Conformation
• Segmental Motion
• ¹³C-Nuclear Magnetic Resonance
• T₁ Relaxation