Chemical Profiling of Piper longum Linn

The characterization chemical ingredients of P. longum Linn were carried out as described previously study [23 (link),24 (link)]. Dionex UltiMate 3000 system (LabX, Midland, ON, Canada) with a Thermo Q-Exactive mass spectrometer (UHPLC-MS/MS, Thermo Fisher Scientific) were used for analysis. All tested compounds were separated using an Acquity BEH C18 column (100 × 2.1 mm, 1.7 μm) with water and acetonitrile containing 0.1% formic acid. The mass spectra of P. longum Linn analyzed using a heated electrospray ionization source. The full scan mass spectra were acquired in positive ion mode at a scan range of 100–1500 m/z in data-dependent MS2 scan mode. Data acquisition and analysis were based on Xcalibur and TraceFinder software (Thermo Fisher Scientific). The reference standards, magnoflorine and piperine, were purchased from Targetmol (Wellesley Hills, MA, USA).