High-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry and gas chromatography-flame ionization detection characterization of Delta5-polyenoic fatty acids in triacylglycerols from conifer seed oils.
Edible conifer seeds can serve as a source of triacylglycerols (TGs) with unusual Delta5 unsaturated polymethylene interrupted fatty acids (UPIFAs), such as cis-5,9-octadecadienoic (taxoleic), cis-5,9,12-octadecatrienoic (pinolenic), cis-5,11-eicosadienoic (keteleeronic) and cis-5,11,14-eicosatrienoic acids (sciadonic). Conifer seed oils from European Larch (Larix decidua), Norway Spruce (Picea abies) and European Silver Fir (Abies alba) have been analyzed by non-aqueous reversed-phase high-performance liquid chromatography (NARP-HPLC) with atmospheric pressure chemical ionisation (APCI)-MS detection. The influence of different positions of double bonds in Delta5-UPIFAs on the retention and fragmentation behavior is described and used for the successful identification of TGs in each oil. TGs containing Delta5-UPIFAs have a higher retention in comparison with common TGs found in plant oils with single methylene interrupted Delta6(9)-FAs and also significantly changed relative abundances of fragment ions in APCI mass spectra. Results obtained from HPLC/MS analyses are supported by validated GC/FID analyses of fatty acid methyl esters after the transesterification. The total content of Delta5-UPIFAs is about 32% for European Larch, 27% for Norway Spruce and 20% for European Silver Fir. In total, 20 FAs with acyl chain lengths from 16 to 24 carbon atoms and from 0 to 3 double bonds have been identified in 64 triacylglycerols from 3 conifer seed oils.
Lísa
Miroslav
M
Department of Analytical Chemistry, Faculty of Chemical Technology, University of Pardubice, Czech Republic.
Holcapek
Michal
M
Rezanka
Tomás
T
Kabátová
Nadezda
N
D001274:Atmospheric Pressure; D002849:Chromatography, Gas / Q000295:instrumentation / Q000379:methods*; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D005231:Fatty Acids, Unsaturated / Q000032:analysis*; D005410:Flame Ionization; D028221:Larix / Q000737:chemistry*; D010938:Plant Oils / Q000737:chemistry*; D015203:Reproducibility of Results; D012639:Seeds / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation / Q000379:methods; D009626:Terminology as Topic; D014280:Triglycerides / Q000737:chemistry*
D005231:Fatty Acids, Unsaturated; D010938:Plant Oils; D014280:Triglycerides; C445137:delta5 polyunsaturated fatty acid