Xevo g2 qtof ms spectrometer

LC-MS/MS analysis was carried out by using UHPLC systems (Ultimate 3000, Thermo Scientific, Milan, Italy) coupled to a Waters Xevo G2 QTOF MS spectrometer (Waters, Co., Milford, MA, USA) with an Acquity UPCL BEH C18 column (2.1 × 100 mm, 1.7 μm). The mobile phase was composed of 0.1% formic acid in water (A) and 0.1% formic acid in acetonitrile (B). The gradient program was as follows: 0–20 min, linear gradient of 10% to 90% B; 20–22 min, isocratic at 100% B; 22–24 min, return to the initial conditions. The flow rate was 0.3 mL/min, and the injection volume was 2 μL during the acquisition of negative polarity. The MS/MS analysis was performed in data-dependent scan mode, ranging from m/z = 100 to m/z 1500. All LC-MS/MS data were converted to mzXML files by MZmine-2.38. Molecular networking was carried out via the GNPS web platform (https://gnps.ucsd.edu, accessed on 7 January 2019). The spectral networks were visualized in Cytoscape 3.7.1 (www.cytoscape.org, accessed on 8 January 2019).

Optical rotations were recorded on a JASCO P-2000 polarimeter (JASCO International Co., Ltd., Tokyo, Japan). IR data were collected using a Nicolet 6700 FT-IR spectrometer (Thermo Electron Corp., Waltham, MA, USA). ECD spectra were obtained using Chirascan Plus (Applied Photophysics Ltd., Surrey, United Kingdom). A Waters Xevo G2 QTOF MS spectrometer (Waters Co., Milford, MA, USA) was used for high-resolution electrospray ionization mass spectrometry (HRESIMS) values. Semipreparative HPLC experiments were performed using a Gilson HPLC system with a 321 pump and a UV/VIS-155 detector. A Phenomenex Phenyl-Hexyl column (10 × 250 mm, 5 μm particle size, USA) was used as the HPLC column. The NMR spectra for 1D (¹H and ¹³C) and 2D (HSQC, HMBC, NOESY, and ROESY) were measured on a Varian Unity Inova spectrometer at 500 MHz (Agilent Technologies, Santa Clara, CA) and an AVANCE spectrometer at 800 MHz (Bruker, Germany). YMC*Gel ODS-A and Sephadex LH-20 were used for column chromatography. Thin-layer chromatography experiments were performed with silica gel 60 F₂₅₄ and RP-18 F₂₅₄ plates. A Gilson semi-Prep HPLC system was composed of a flow rate of 3 mL/min and UV detection at 201 and 254 nm. All solvents (Dae Jung Pure Chemical, Siheung, Korea) for extraction and isolation were of analytical grade.

Optical rotations were measured on a JASCO P-2000 polarimeter (JASCO International Co. Ltd., Tokyo, Japan). IR data were collected using a Nicolet 6700 FT-IR spectrometer (Thermo Electron Corp., Waltham, MA, USA). ECD spectra were recorded using Chirascan Plus (Applied Photophysics Ltd., Surrey, UK). UHPLC systems (Ultimate 3000, Thermo Scientific, Milan, Italy) coupled to a Waters Xevo G2 QTOF MS spectrometer (Waters, Co., Milford, MA, USA) were used to generate HRESIMS values and perform LC-MS/MS analysis. Semipreparative HPLC was performed using a Gilson HPLC system with a UV/VIS-155 detector and a 321 pump. An RS Tech Optima Pak C18 column (10 × 250 mm, 10 μm) was used as the HPLC column. All solvents employed for extraction and isolation were of analytical grade. The 1D (¹H and ¹³C) and 2D (HSQC, HMBC and ¹H-¹H COSY) NMR spectra were collected using JEOL 400 MHz (JEOL Ltd., Tokyo, Japan), Bruker Avance 500 MHz and Bruker Avance 800 MHz NMR spectrometers (Bruker, Billerica, MA, USA). Diaion^TM HP-20 ion exchange resin and GE Healthcare Sephadex^TM LH-20 (18–111 μm) were employed for column chromatography. Thin layer chromatography was performed with silica gel 60 F₂₅₄ and RP-18 F₂₅₄ plates.