Abstract: Our previous study showed that Panax ginseng aqueous extract showed memory-enhancement effect on mice.In this study,two ginseng components (named P1 and P2) were separated from the aqueous extract of P.ginseng through ultrafiltration,dialysis and Sephadex G-15 column chromatography.Their memory-enhancement effect was tested by Morris water maze and step-down experiments.The results of pharmacologic experiment showed that P2 improved the disturbance of memory acquisition and consolidation in mice by i.p.at the dose of 40 mg/kg for 7 days.Hence,P2 was the active site of the ginseng aqueous extract with memory-enhancement effect.The structural identification of P2 by nano-ultra performance liquid chromatography coupled to LTQ Orbitrap Elite mass spectrometry (Nano LC-MS/MS) was undertaken,the MS/MS ion spectra were evaluated through Uniprot all species sequence database and Proteome Discoverer software,then 22 novel peptides were firstly identified from P.ginseng.

Key words: Panax ginseng, LC-MS/MS, memory-enhancement activity, peptide