Stereochemistry of 2,3-alkanediols obtained from the Harderian gland of Mongolian gerbil (Meriones unguiculatus).

The stereochemistry of the alcohol moieties of 2,3-alkanediol diacyl esters obtained from the Harderian gland of the Mongolian gerbil was investigated. There were five major 2,3-alkanediols, C14-C22 (even carbon numbers), all having the erythro configuration as determined by GC-MS analysis of their isopropylidene derivatives in comparison with synthetic erythro- and threo-2,3-hexadecanediols. 13C-NMR spectroscopy of the synthetic materials showed distinct differences of chemical shift at the C-1, C-3, and C-4 carbons, from which the native 2,3-alkanediols were definitely determined to be in the erythro series. The absolute configurations of the C-2 and C-3 asymmetric centers were assigned as 2S and 3R, respectively, based on known 2S,3R-octanediol.

The characterization of 2,3-alkanediol diacyl esters obtained from the Harderian glands of Mongolian gerbil (Meriones unguiculatus).

A major lipid class in the Harderian glands of the Mongolian gerbil was investigated. The IR and 1H-NMR spectra suggested that it was a wax-like compound. Fatty acids present were capric, lauric, myristic, palmitic, stearic, arachidic, and behenic acids in ratios of 3.0%, 16.3%, 16.5%, 29.5%, 5.1%, 16.4%, and 9.8%, respectively. Odd-numbered, branched chain and unsaturated fatty acids were not present in large amounts. The structure of the alcohol moiety was elucidated to be 2,3-alkanediol with carbon chain lengths from C12 to C22 by GC-MS of the TMS and isopropylidine derivatives. Lemieux-von Rudloff oxidation of these alcohols confirmed the 2,3-diol structure, giving fatty acids two carbon units shorter.