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 separa ted for the first time by chiral capillary electrophoresis (CE) employing v arious buffers and chiral selectors on the basis of the results achieved in 1998 in our research group by Mellenthin. The following chiral additives t o the background electrolyte (BGE) were examined: native cyclodextrins (CDs ; alpha-, beta- and gamma -CD), neutral cyclodextrin derivatives (dimethyl- beta -CD, hydroxypropyl-beta -CD, hydroxypropyl-gamma -CD) and charged cycl odextrin derivatives (carboxymethyl-beta -CD, carboxyethyl-beta -CD). The e ffect of CD type, CD concentration and pH value on chiral recognition will be discussed in the following article. In this work, lemon juice (Citrus li mon L.) was also examined by chiral CE. Eriocitrin and hesperidin could be identified as characteristic flavanones and chiral separation of their dias tereomers could be achieved according to the developed chiral method by cap illary electrophoresis using a 0.2 M borate buffer at pH 10.0 and with 5 mM gamma -CD as chiral selector. (C) 2001 Elsevier Science B.V. All rights re served.