Chemical investigation of Pinguicula lusitanica by HPLC-MS and HPLC-SPE-NMR

Eight compounds from the methanolic extract of in vitro grown Pinguicula lusitanica (L.), including four iridoid and two phenylethanoid glycosides, were isolated and tentatively assigned. P. lusitanica is an insectivorous plant that grows wild along the coastal area of Western Europe, from Scotland to Iberia, and Morocco in north-western Africa [1]. Wild populations of P. lusitanica are becoming increasingly scarce emphasizing the importance of in vitro cultures, which provide a fast mean of obtaining large quantities of plant material without jeopardizing the vulnerable wild populations. Previous analysis by GC-MS reported the presence of compounds with biological activity in the volatile fraction of the methanolic extract. The extract was prepared by grinding in vitro grown P. lusitanica shoots and extracting with methanol while being continuously stirred. The extract was filtered, concentrated in a rotary-evaporator under reduced pressure, dissolved in water and freeze dried. The crude extract was cleaned from apolar compounds using a SPE column before being analyzed by HPLC-MS/SPE-NMR. All major peaks of the HPLC chromatogram were trapped with SPE cartridges and subsequently analyzed by 1H-NMR. This study describes the chemical investigation of the insectivorous plant species P. lusitanica by HPLC-MS/SPE-NMR which made it possible to obtain a chemical profile in short time in comparison to traditional preparative chromatography methods [2].