Comparison of hydrogen bonding for chiral and racemic 1-monostearoylglycerols in solvent.

ABSTRACT

Comparison of the hydrogen bonding of racemic RS-1-monostearoylglycerol and chiral S-1-monostearoylglycerol in benzene was carried out through the NMR measurement. In addition, the concentration dependence of a chirality of S-1-monostearoylglycerol in hexane was studied though UV and circular dichroism (CD) measurements. The chemical shifts of OH protons of the S- and RS-1- monostearoylglycerols indicated that the hydrogen bonding between the R- and S-form molecules of RS-1-monostearoylglycerol is stronger than that between the S- and S-form molecules of S-1-monostearoylglycerol in the low concentration region and that the difference in the strength of hydrogen-bonding between them becomes small in the high concentration region. The chirality of the S-1-monostearoyglycerol in hexane decreased with increasing its concentration. This suggests that the association of chiral S-1-monoacylglycerol arising from its increasing concentration reduces the chirality of S-1-monostearoylglycerol.