Accelerated dereplication of crude extracts using HPLC-PDA-MS-SPE-NMR: Quinolinone alkaloids of Haplophyllum acutifolium

Direct hyphenation of high-performance liquid chromatography, photo-diode array detection, mass spectrometry, solid-phase extraction and nuclear magnetic resonance spectroscopy (HPLC-PDA-MS-SPE-NMR) has been used for accelerated dereplication of crude extract of Haplophyllum acutifolium. This allowed fast on-line identification of six quinolinone alkaloids, named haplacutine A-F, as well as acutine, haplamine, eudesmine, and 2-nonylquinolin-4(1H)-one.