IUCr journals

The β-2 and β´-2 polymorphs of trans-mono-unsaturated triacylglycerols and related fully saturated triacylglycerols

Acta Cryst. (2008). B64, 240–248 [doi:10.1107/S0108768108004813]; 249–259 [doi:10.1107/S0108768108004825]

[Rietveld refinement result]Rietveld refinement result of β1-2 PEP (1,3-dipalmitoyl-2-elaidoylglycerol) from high-resolution laboratory data and packing view parallel to the b axis.
With a parallel tempering method (FOX) crystal structures have been solved of the β-2 and β1-2 polymorphs of various saturated and trans-mono-unsaturated triacylglycerols (TAGs) using 3 Å resolution synchrotron and laboratory powder diffraction data. Also, the crystal structure has been solved of a novel β´-2 polymorph that melts higher than the β1-2. Molecular conformations of symmetric vs asymmetric TAGs in the β1-2 polymorph are different while in the β-2 they are the same. The structures imply that a β´-2 to β-2 solid-state conversion is unlikely.

J.B. van Mechelen, R. Peschar and H. Schenk