Agilent qtof 6520

All of the solvents and reagents were obtained from commercial sources (Innochem, Beijing, China; Bidepharm, Shanghai, China; J&K scientific, Beijing, China) and used without further purification unless otherwise noted. The reactions were monitored by using thin-layer chromatography (TLC, Qingdao Ocean Chemical Co., Ltd., Qingdao, China) with silica gel HSGF254 precoated plates (0.2 mm), and the compounds were visualized under UV light (λ = 254 or 365 nm) and/or stained with iodine. Column chromatography was performed on silica gel (100–200 mesh). ¹H and ¹³C spectra were taken in CDCl₃, MeOH-d₄ or DMSO-d₆ on Bruker Ascend 400 MHz or Ascend 700 MHz spectrometers (Bruker, Massachusetts, Germany) with tetramethylsilane (TMS) as an internal standard. High-resolution mass spectra (HRMS) were obtained with an Agilent Q-TOF 6520 (Agilent Technologies Inc., Santa Clara, CA, USA). The spectra of compounds are shown in Table S5.

Commercially available reagents were used without further purification. Organic solvents were evaporated with reduced pressure using a Büchi R-100 evaporator (Büchi, Flawil, Switzerland). Reactions were monitored by TLC using Yantai Jingyou (Yantai, China) GF254 silica gel plates. Silica gel column chromatography was performed on Biotage Isolera One (Biotage, Uppsala, Sweden) using silica gel (200–300 mesh) from Qingdao Hailang (Qingdao, China). NMR spectra were measured on Bruker Avance III 600 MHz spectrometers (Bruker, Fällanden, Switzerland). Chemical shifts were expressed in δ (ppm) and coupling constants (J) in Hz with solvent signals as internal standards (CDCl₃, δ_H 7.26 ppm and δ_C 77.0 ppm; DMSO-d₆, δ_H 2.50 ppm and δ_C 39.5 ppm). ESI-MS (electrospray ionization mass spectrometry) analyses were performed on an Agilent 1260–6460 Triple Quard LC-MS instrument (Agilent, Waldbronn, Germany), and HR-ESIMS data were acquired on an Agilent Q-TOF 6520 (Agilent, Waldbronn, Germany).

MS/MS: The elucidation of the structure was performed on an Agilent QTOF 6520 coupled to a LC1200 (Agilent technologies, Santa Clara, CA, USA). Briefly, the compounds were separated with a Poroshell 120, EC-C18, 2.1 × 100 mm, 2.7 μm column, preceded by a Poroshell 120, EC-C18, 2.1 × 5 mm, 2.7 μm guard column, using formic acid 0.1% in water/acetonitrile with 0.1% of formic acid gradient (1% acetonitrile for 2 min increasing to 75% in 18 min and to 100% in 2 min, then kept at 100% for 4 min. Before decreasing to 1% for 0.2 min, the column was reequilibrated for 3 min). The TargetMS/MS mode was operated with the following parameters: source; gas temperature 325 °C, Drying gas 9 L/min, nebulizer, 45 psig, VCap 4500 V, fragmentor 175 V. The precursor ions selected were respectively m/z 607.2027 and m/z 605.1876 for positive and negative mode with an isolation window of ± 4 amu. The collision energies of 5, 15, 25, 40 and 55 eV were applied during the run and MS/MS range spectra were between m/z 50 and 1000. The data were analyzed with MassHunter qualitative analysis version B.07 from Agilent Technologies where precursor and product ions structures were estimated.

All commercially available solvents and reagents were purchased from a local commercial supplier (Yuwang Chemical Industries, Ltd., Shenyang, China) and used directly. Melting points (m.p.) were tested using micro melting point apparatus XT-4 (Taike, Beijing, China) and not corrected. Infrared (IR) spectra were recorded on a Nicolet Impact 410 instrument (Thermo Fisher Scientific, Waltham, MA, USA) using a KBr pellet. ¹H and ¹³C NMR spectra were taken (TMS as internal standard) on a Bruker AV-300 (Bruker Corp., Karlsruhe, Germany) or ACF 500 spectrometer (Bruker Corp., Karlsruhe, Germany) in CDCl₃. Low resolution mass spectra (MS) were carried out using FTMS-2000 (Thermo Fisher Scientific, Waltham, MA, USA). High resolution mass spectra (HR-MS) were obtained with Agilent QTOF 6520 (Agilent Technologies China, Beijing, China).