Analysis of Fatty Acid Steryl Esters in Tetraploid and Hexaploid Wheats:  Identification and Comparison between Chromatographic Methods

Abstract

Fatty acid steryl esters (FASE) in whole meal of 14 genotypes of tetraploid wheats (Triticum dicocconand T. durum) and 17 genotypes of hexaploid wheats (T. spelta and T. aestivum) were analyzed using different chromatographic strategies. By both GC-FID and HPLC-ELSD, tetraploid wheats are lacking two major peaks. The amounts of FASE, calculated on the basis of the GC-FID analysis, were double in hexaploid species as compared to tetraploids (40 and 20 mg/100 g db, respectively). HPLC with ESI-MS detection enabled the identification of FASE by the characteristic fragmentations and ion-adducts of each molecule. The distribution of steryl residues was not different between the wheat species: the main class of steryl derivatives found was the beta-sitosteryl derivatives, followed by campesteryl derivatives with small amounts of stigmasteryl esters. The esterified fatty acids explain the difference between the hexaploid and tetraploid wheats. In particular, small amounts of campesteryl and beta-sitosteryl, while no trace of stigmasteryl palmitates, were found in T. durum or its hulled ancestor T. dicoccon. Steryl oleates were not detectable in T. aestivum or its hulled ancestor T. spelta, which is consistent with the filogenesis of tetraploid and hexaploid species. Both chromatographic techniques (GC and HPLC) showed that FASE are useful to discriminate between hexaploid and tetraploid wheats from both qualitative and quantitative points of view.

Characterization of Total, Free and Esterified Phytosterols in Tetraploid and Hexaploid Wheats

“…Evaluation of combined FS and ES showed that the two fractions of phytosterol are similar for varieties belonging to the same species; in hexaploid wheats they represented 47.7-55.7 mg/100 g, whereas in tetraploid wheats the combined FS and ES were 63.6-65.4 mg/100 g. The sum of different FS and ES in wheats is in agreement with the data presented by RuibalMendieta et al (15), who reported that the combined FS and ES content of spelt and soft wheat were 52.7-52.8 mg/100 g, in accordance with another study of unhydrolyzed sterol esters (11).…”

Capillary gas chromatographic analysis of complex phytosteryl/-stanyl ester mixtures in enriched skimmed milk-drinking yoghurts

“…In this way, information regarding the fatty acid composition of the steryl esters is lost. Approaches for the analysis of intact esters have also been reported (Barnsteiner, Lubinus, di Gianvito, Schmid, & Engel, 2011;Caboni, Iafelice, Pelillo, & Marconi, 2005;Gordon & Griffith, 1991;Gunawan, Melwita, & Ju, 2010;Kamm et al, 2001;Mezine, Zhang, Macku, & Lijana, 2003).…”

Secondary Metabolites from the Mycelia of the Fungus Monascus pilosus BCRC 38072

“…Compound 3 was first isolated from a natural source, though it has since been synthesized. 20) The other known isolates, b-sitosteryl stearate, 21) a mixture of b-sitosterol and stigmasterol, 22) ergosterol, 23) p-hydroxybenzoic acid, 24) methylparaben, 25) trans-caffeic acid, 26) linoleic acid, 27) cyclo-(L-Pro-L-Tyr), 28) 5-(hydroxymethyl)furfural, 29) (Z)-pulchellalactam, 30) and (4R,5S)-5-hydroxyhexan-4-olide, 31) were readily identified by comparison of their physico-chemical, spectroscopic, and mass-spectrometric data with the literature. Except for linoleic acid, this is the first time any of the compounds described above have been isolated from Monascus spp.…”