1: Chem Phys Lipids  2002 Oct;119(1-2):13-21 

Polymorphism of N-stearoylethanolamine: differential scanning calorimetric,
vibrational spectroscopic (FTIR), and crystallographic studies.

Wouters J, Vandevoorde S, Culot C, Docquir F, Lambert DM.

Faculte des Sciences, Facultes universitaires Notre Dame de la Paix, Rue de
Bruxelles, 61, 5000 Namur, Belgium.

Based on a series of physicochemical properties (differential scanning
calorimetry, powder X-ray crystallographic studies and Fourier-transform infra
red spectroscopic analysis) determined for N-stearoylethanolamine (NSEA) (C18:0)
at different temperatures, evidence has been given that this compound can exist
in (at least) three polymorphic forms. Powder X-ray crystallography clearly
demonstrates the presence of three distinct molecular packings at distinct
temperatures while spectral changes in the vibrational spectra reveal that the
geometry of the CH(2)z.sbnd;CO functional group of the molecule is affected
during the polymorphic transitions. Rationalization of the thermal
physicochemical behavior of NSEA in terms of molecular packing is also proposed.
It supposes rearrangement of the hydrocarbon chains upon heating of the
molecule.

PMID: 12270669 [PubMed - indexed for MEDLINE]