Synapt g2 tof mass spectrometer

Optical rotations were measured on a JASCO P1020 digital polarimeter, and UV data were obtained with a JASCO V-550 UV/vis spectrometer. The CD spectra were recorded in MeOH using a JASCO J-810 spectrophotometer at room temperature. IR data were recorded using JASCO FT/IR-480 Plus spectrometer. HRESIMS spectra were obtained on Waters Synapt G2 TOF mass spectrometer. The NMR data were acquired with a Bruker AV 400 NMR spectrometer using solvent signals (CD₃OD: δ_H 3.30/δ_C 49.0) as standards. Column chromatography (CC) was carried out on Sephadex LH-20 (Pharmacia, USA), and ODS (60–80 μm, YMC). TLC was performed on precoated silica gel plate (SGF254, 0.2 mm, Yantai Chemical Industry Research Institute, China). Analytical HPLC was performed on a Dionex HPLC system equipped with an Ultimate 3000 pump, an Ultimate 3000 diode array detector, an Ultimate 3000 column compartment, an Ultimate 3000 autosampler (Dionex, USA), and an Alltech (Grace) 2000ES evaporative light scattering detector (Alltech USA) using a Phenomenex Gemini C18 column (4.6 × 250 mm, 5 μm). Preparative HPLC was carried out on Shimadzu LC-6AD system equipped with UV detectors, using a Phenomenex Gemini C18 column (21.2 × 250 mm, 5 μm). Semi-preparative HPLC was carried out on Shimadzu LC-6AD system equipped with UV detectors, using a YMC-Pack ODS-A column (10.0 × 250 mm, 5 μm).