Separation of flavanone-7-O-glycoside diastereomers and analysis in citrus juices by multidimensional liquid chromatography coupled with mass spectrometry.
The major flavanone-7-O-glycoside constituents in citrus fruit juices (naringin, hesperidin, neohesperidin, narirutin, and eriocitrin) were separated as diastereomers by multidimensional liquid chromatography. The method consisted of coupling two HPLC columns: a reversed-phase (RP(18)) column was used for the separation of flavanone glycosides, which were, then, individually switched into a carboxymethylated beta-cyclodextrin (beta-CD)-based column and resolved as the corresponding stereoisomers. The method was used for the full analysis of flavanone glycosides in fresh hand-squeezed and commercial fruit juices by combining the quantitative estimation with the diastereomeric analysis. Quantitative data were in general consistent with previously reported data in this field. CC-LC isomer analysis was carried out by coupling the beta-CD column with a mass spectrometer operated with negative ion electrospray ionization (ESI-MS). The results showed that hesperidin was present in orange juices almost exclusively as the 2S isomer, whereas narirutin had mainly the 2R configuration. In grapefruit juices (2S)-naringin prevailed with the respect to the 2R isomer, whereas the opposite was true for narirutin. Lemon juices contained eriocitrin stereoisomers in equal amount (50% each), but hesperidin was almost exclusively found as the 2S isomer. Significant differences of the diastereomeric ratios were observed between freshly squeezed juices and juices from commercial sources.
Aturki
Zeineb
Z
Istituto di Metodologie Chimiche, CNR-Area della Ricerca di Roma 1, P.O. Box 10, 00016 Monterotondo Stazione, Rome, Italy.
Brandi
Valentina
V
Sinibaldi
Massimo
M
D001628:Beverages / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D002957:Citrus / Q000737:chemistry*; D044950:Flavanones / Q000032:analysis / Q000302:isolation & purification*; D005638:Fruit / Q000737:chemistry*; D006027:Glycosides / Q000032:analysis / Q000302:isolation & purification*; D013058:Mass Spectrometry; D013237:Stereoisomerism
D044950:Flavanones; D006027:Glycosides