Characterization of sn-2 Alk-1'-Enyl Ethers of Glycerol from Rice Bran Oil

Abstract

Ether lipids have biological applications which would dissipated as an important constituent in cell membranes. These are mostly found in animal tissues and rare in plant origin. Alk-1'-enyl ethers are class of ether lipid forming aldehydes on cleavage of ether bonds. The present study enrolled the presence of aldehyde in unsaponifi able matter of rice bran oil (RBO) and hence the identifi cation of source of aldehydes in RBO was conducted. With respect to the earlier reports the investigation turned to major lipid constituents such as triacylglycerols, diacylglycerols etc. Using the column chomatographic method lipid fractions are separated, recolumned, purified and analyzed by spectrochemical methods such as FT-IR, 1 HNMR, 13 CNMR, Mass spectrometry and confirmed the presence of ether lipids. The sn-2 position was confi rmed by enzymatic hydrolysis using pancreatic lipase. Moreover the formation of aldehyde from these ether lipids was also confi rmed by spectrometric methods.

Effect of saponification on composition of unsaponifiable matter in rice bran oil

“…The source of fatty aldehydes in RBO and the spectra of long chain aldehydes were illustrated in our previous report 19 and briefl y as follows. …”

“…After eluting the band with chloroform, policosanol and fatty aldehydes were further separated on preparative TLC by the solvent system toluene: chloroform 7:3 v/v .The bands with R f of 0.52 and 0.68 corresponding to policosanol and aldehydes respectively were eluted from silica gel and subjected to 1 HNMR, 13 CNMR, FT-IR and mass spectrometric studies 16 18 for confirmation and used as reference standards. The separated fatty aldehydes were methylated 19 and used as reference standards. 2.5.2 Quantifi cation of fatty aldehydes using GC The fatty aldehydes as their dimethyl acetal esters were quantifi ed by the method reported by us 19 and briefl y described as follows.…”

“…The separated fatty aldehydes were methylated 19 and used as reference standards. 2.5.2 Quantifi cation of fatty aldehydes using GC The fatty aldehydes as their dimethyl acetal esters were quantifi ed by the method reported by us 19 and briefl y described as follows. The instrument used was GC-2010 Shimadzu, Japan and separated in a capillary column DB-23 30 m length, 0.32 mm id wide bore , 0.25 μm fi lm thickness Agilent Technologies, USA .The temperature conditions was as follows: 2 min hold at 180 for and then oven temperature was programmed to increase to 200 at the rate of 5 /min and held at 200 for 5 min.…”