HPLC, HPLC-electrospray ionization (LC-ESI), and LC-FABMS were used to characterize flavonoid glycosides in the methanol extract from peanut meal. Five isoflavones, daidzin, glycitin, genistin, daidzein, and genistein, were separated by HPLC and characterized by comparison with known standards using ESI-MS. The flavonoid methylquercetin (rhamnetin) was present in the methanol extract from peanuts and identified by ESI-MS. Four other flavonoids, two quercetin diglycosides, one quercetin monoglucoside, and isorhamnetin glucoside, were found to be present in the methanol extract based on their reversed-phase elution pattern, mass ions, and fragment ions using flow-FABMS. FIG. 2. HPLC chromatogram overlay of the MeOH extract from peanut meal and a standard mixture of the isoflavones daidzin (1), glycitin (2), genistin (3), daidzein (4), and genistein (5).FIG. 1. Isoflavone skeleton, positional specificity, and M.W.

Total lipid extracts from peanut seed were separated on a silica column into a triacylglycerol fraction and a polar lipid fraction by high-performance liquid chromatography (HPLC). The polar fraction containing the phospholipids was retained on the precolumn, and the triacylglycerol fraction was eluted to a waste flask by a special valve arrangement. Phospholipids were eluted from the precolumn and separated into various classes on a silica analytical column. Each phospholipid class was manually collected and subsequently subjected to reversed-phase HPLC in tandem with a fast atom bombardment mass spectrometer. Phosphatidylethanolamine was separated into five molecular species. Phosphatidylinositol and phosphatidylcholine were each separated into six molecular species.Paper no. J8689 in JAOCS 76, 49-56 (January 1999). FIG. 3. HPLC separation of phospholipid molecular species detected by full-scan analysis with FAB-mass spectrometry (MS). (A) PE molecular species, (B) PI molecular species, (C) PC molecular species. See Figures 1 and 2 for other abbreviations.