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Ab initio and DFT study of 31 P‐NMR chemical shifts of sphingomyelin and dihydrosphingomyelin lipid molecule
Author(s) -
Sugimori K.,
Kawabe H.,
Nagao H.,
Nishikawa K.
Publication year - 2009
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.22404
Subject(s) - conformational isomerism , chemistry , sphingomyelin , chemical shift , ab initio , density functional theory , hydrogen bond , intramolecular force , molecule , proton nmr , nuclear magnetic resonance spectroscopy , crystallography , stereochemistry , computational chemistry , membrane , organic chemistry , biochemistry
One of the phospholipids, sphingomyelin (SM, N ‐acyl‐sphingosine‐1‐phosphorylcholine) is the most abundant component of mammalian membranes in brain, nervous tissues, and human ocular lens. It plays an important role for apoptosis, aging, and signal transduction. Recently, Yappert and coworkers have shown that human lens sphingomyelin and its hydrogenated derivative, dihydrosphingomyelin (DHSM) are interacted with Ca 2+ ions to develop human cataracts. Previously, we have investigated conformational differences between an isolated SM/DHSM molecule and Ca 2+ ‐coordinated form by using density functional theory (DFT) for geometry optimization and normal mode analysis. As a result, one of stable conformers of SMs has a hydrogen bonding between hydroxyl group and phosphate group, whereas another conformer has a hydrogen bonding between hydroxyl and phosphate amide group. In this study, 31 P‐Nuclear Magnetic Resonance (NMR) shielding constants of the obtained conformers are investigated by using ab initio and DFT with NMR‐gauge invariant atomic orbitals (NMR‐GIAO) calculations. The experimental 31 P‐NMR chemical shifts of SMs and DHSMs have significant small value around 0.1 ppm. We consider the relative conformational changes between SMs and DHSMs affect the slight deviations of 31 P‐NMR chemical shifts, and discuss intramolecular hydrogen bondings and the solvent effect in relation to NMR experimental reference. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009