Detection and isolation by MS-coupled preparative HPLC of lysophosphatidylcholine derivatives from goji berries (Lycium barbarum)

Goji (Lycium barbarum, Solanaceae) berries and juice are being sold as health food products and praised in advertisements and in the media for well-being and as an anti-aging remedy [1]. While the fruit itself is devoid of toxicity there have been increasing concerns about the quality of goji products with respect to pesticide contamination or possible adulteration. As part of our investigations on goji, we detected in HPLC chromatograms of extracts a group of late-eluting compounds devoid of UV absorption. Their molecular weight could not be assigned to any known constituents of goji berries. An approach based on MS-coupled preparative HPLC was used for the isolation of these compounds. The experimental setup consisted of a HPLC-MS instrument equipped with an adjustable flow splitter and an additional pump delivering a make-up flow. Separations were performed on a semi-preparative RP-18 HPLC column (10×150mm, i.d.). The compounds were identified as lysophopsphatidylcholine derivatives with fatty acid residues of variable length and degree of unsaturation by a combination of spectroscopic and chemical methods including ESI-MS, NMR, and GC analysis of the acyl residue after methanolysis. Interestingly, a mixture of phosphatidylcholine and lysophosphatidylcholine derivatives with related fatty acid composition has been detected in jojoba seeds [2]. On the other hand, such metabolites have not been reported hitherto in goji berries. These compounds may be useful as chromatographic markers for the analysis of goji products. At the same time they may give new hints with respect to the biological properties of goji berries and products.

References: 1. Potterat O (2010) Planta Med. 76:7–19.

2. Leon F, Van Boven M, De Witte P, Busson R, Cokelaere M (2004)J. Agric. Food Chem. 52:1207–1211.