Chiral separation of six diastereomeric flavanone-7-O-glycosides by capillary electrophoresis and analysis of lemon juice

The diastereomers of six major flavanone-7-O-glycosides (naringin, prunin, narirutin, hesperidin, neohesperidin and eriocitrin) were completely separated for the first time by chiral capillary electrophoresis (CE) employing various buffers and chiral selectors on the basis of the results achieved in 1998 in our research group by Mellenthin. The following chiral additives to the background electrolyte (BGE) were examined: native cyclodextrins (CDs; α-, β- and γ-CD), neutral cyclodextrin derivatives (dimethyl-β-CD, hydroxypropyl-β-CD, hydroxypropyl-γ-CD) and charged cyclodextrin derivatives (carboxymethyl-β-CD, carboxyethyl-β-CD). The effect of CD type, CD concentration and pH value on chiral recognition will be discussed in the following article. In this work, lemon juice (Citrus limon L.) was also examined by chiral CE. Eriocitrin and hesperidin could be identified as characteristic flavanones and chiral separation of their diastereomers could be achieved according to the developed chiral method by capillary electrophoresis using a 0.2 M borate buffer at pH 10.0 and with 5 mM γ-CD as chiral selector.