Tof esi ms waters synapt g2

Optical rotations were obtained on a PerkinElmer 241 Polarimeter (Waltham, MA, USA), and CD measurements were performed with a JASCO J-815 Spectropolarimeter. UV data were measured using a Beckman Coulter DU 800 spectrometer (Tokyo, Japan). IR spectra were recorded using a Shimadzu FTIR-8400S spectrophotometer (Tokyo, Japan). NMR spectra were acquired with a Bruker 500 (Munich, Germany) instruments operating at 500 (¹H) and 125 (¹³C) MHz using the solvent signals (CD₃OD: δ_H 3.31/δ_C 49.0 ppm) as references. The HRESIMS experiments were carried out on a TOF-ESI-MS (Waters Synapt G2, USA) equipment. HPLC for purifications were performed on a Waters 2489 Semiprep-HPLC System using an ODS column (RP-18, 250 × 10 mm, YMC Pack, 5 μm; detector: UV; Kyoto, Japan). Sephadex LH-20 (Pharmacia Biotech AB, Uppsala, Sweden) and silica gel (80–100, 100–200, and 200–300 mesh; Qingdao Marine Chemical Plant, Qingdao, China) were used for column chromatography, and thin layer chromatography (TLC) was carried out with glass precoated silica gel GF254 (0.20–0.25 mm; Qingdao Marine Chemical Plant, Qingdao, China).

Optical rotations were measured on a PerkinElmer 241 polarimeter, and UV data were determined on a ThermoGenesys-10S UV-vis spectrometer^{19 (link)}. IR data were recorded using a Nicolet IS5FT-IR spectrophotometer. CD spectra were obtained on a JASCO J-810 spectrometer. ¹H and ¹³C NMR data were acquired with a Bruker 600 spectrometer using solvent signals (DMSO-d₆; δ_H 2.50/δc 39.5) as references. the HMQC and HMBC experiments were optimized for 145.0 and 8.0 Hz, respectively. HRESIMS were obtained using a TOF-ESI-MS (Waters Synapt G2, USA). Semipreparative HPLC separation was carried out using a Lumtech instrument packed with a YMC-Pack ODS-A column (5 μm, 250 × 10 mm). Sephadex LH-20 (Pharmacia Biotech AB, Uppsala, Sweden) and silica gel (200–300 mesh) (Qingdao Marine Chemical Plant, Qingdao, China) were used.