Ft ir 480 spectrophotometer

Optical rotations were measured with Perkin Elmer/Model-343 digital polarimeter. IR spectra were recorded on a JASCO FT/IR-480 spectrophotometer and reported as wave number (cm⁻¹). ¹H, ¹³C NMR spectra and 2D NMR spectra were recorded on a Bruker Avance III 600 spectrometer. Chemical shifts were reported using TMS as the internal standard. HRESIMS data were obtained on a Bruker Apex IV FTMS spectrometer. Column chromatography (CC) was performed on silica gel (90 − 200 µm; Qingdao Marine Chemical Co. Ltd., Qingdao, People’s Republic of China), and MPLC was performed on a Lisui EZ Purify III System packed with RP-18 silica gel (40–63 μm, Merck, 71 Darmstadt, Germany) columns. Precoated silica gel GF254 plates (Qingdao Marine Chemical Co. Ltd., Qingdao, People’s Republic of China) were used for thin-layer chromatography (TLC). Preparative HPLC was performed on Shimadzu LC-8A equipped with a Shimadzu PRC-ODS(K) column and Agilent 1100 apparatus equipped with a Zorbax SB-C-1875 (Agilent, 9.4 mm × 25 cm) column, respectively. The reagents were purchased from Fisher Scientific at the highest quality and were used without further purification.

IR spectra were recorded on a JASCO FT/IR-480 spectrophotometer and reported as wave number (cm⁻¹). ¹ H, ¹³ C NMR spectra and 2D NMR spectra were recorded on a Bruker Avance III 600 spectrometer. Chemical shifts (δ) were expressed in ppm with reference to TMS. HRESIMS data were obtained on an Agilent UPLC/TOF-MS spectrometer. Column chromatography (CC) was performed on silica gel (200‒300 µm; Qingdao Marine Chemical Co. Ltd., China), RP-18 silica gel (SMB-100-25/45, FUJI, Japan) and Sephadex LH-20 (GE Healthcare Bio-Sciences AB SE-75,184 Uppsala, Sweden). Preparative HPLC was performed on Agilent 1100 apparatus equipped with a YMC-Pack ODS-A column (12 µm, 10 × 25 mm). Biological assay data were recorded on microplate reader (Thermo Multiskan PC).

Optical rotations were measured with Perkin Elmer/Model-343 digital polarimeter. IR spectra were recorded on a JASCO FT/IR-480 spectrophotometer and reported as wave number (cm⁻¹). ¹H, ¹³C NMR spectra and 2D NMR spectra were recorded on a Bruker Avance III 600 spectrometer. Chemical shifts were reported using TMS as the internal standard. HR-ESI–MS data were obtained on a Bruker Apex IV FT-MS spectrometer. Column chromatography (CC) was carried out using D-101 macroreticular resin (Tianjin Polymer Technology Co. Ltd.), MCI gel (75–150 μm, Mitsubishi Chemical Industries, Japan) and silica gel (90–200 µm; Qingdao Marine Chemical Co. Ltd., Qingdao, People’s Republic of China). MPLC was performed on a Lisui EZ Purify III System packed with RP-18 silica gel (40–63 μm, Merck, 71 Darmstadt, Germany) columns. Precoated silica gel GF254 plates (Qingdao Marine Chemical Co. Ltd, Qingdao, People’s Republic of China) were used for thin-layer chromatography (TLC). Preparative HPLC was performed on Shimadzu LC-8A equipped with a Shimadzu PRC-ODS(K) column and Agilent 1100 apparatus equipped with a Zorbax SB-C-1875 (Agilent, 9.4 mm × 25 cm) column, respectively.