Thermo mat95xp high resolution mass spectrometer

IR spectra were carried out on a Shimadzu IR Affinity-1 spectrophotometer (Shimadzu Corporation, Kyoto, Japan). UV data was acquired using a Shimadzu UV-2600 spectrophotometer (Shimadzu Corporation, Kyoto, Japan). Optical rotations were obtained on an Anton Paar MCP-500 (Anton Paar, Graz, Austria). Circular dichroism (CD) spectra were recorded on a Jasco 820 spectropolarimeter (Jasco Corporation, Kyoto, Japan). NMR spectra were determined on a Bruker Avance-400 spectrometer (Bruker Corporation, Fremont, CA, USA). ESI-MS spectra were measured on an Agilent Technologies 1290-6430A Triple Quad LC/MS (Agilent Technologies Inc., Santa Clara, CA, USA), and HRESIMS was measured on a Thermo MAT95XP high-resolution mass spectrometer (Thermo Fisher Scientific, Bremen, Germany). A Shimadzu LC-20 AP (Shimadzu Corporation, Kyoto, Japan) equipped with an SPD-M20A Photo-Diode Array (PDA) detector (Shimadzu Corporation, Kyoto, Japan) was used for HPLC analysis. A YMC-pack ODS-A column (250 × 20 mm, 5 μm, 12 nm, YMC CO., Ltd., Kyoto, Japan) was used for preparative HPLC separation. Column chromatography was conducted using a commercial silica gel (SiO₂; 200–300 mesh; Qingdao Haiyang Chemical Co. Ltd., Qingdao, China) and Sephadex LH-20 gel (Amersham Biosciences, Uppsala, Sweden). All solvents were of analytical grade (Guangzhou Chemical Regents Company, Ltd., Guangzhou, China).

Optical rotations were recorded using an Anton Paar MCP-500 spectropolarimeter (Anton Paar, Graz, Austria). UV spectra were obtained by a Shimadzu UV-2600 spectrophotometer (Shimadzu, Kyoto, Japan). ECD spectra were measured with an Applied Photophysis Chirascan. IR data were measured on a Shimadzu IR Affinity-1 spectrometer (Shimadzu, Kyoto, Japan). 1D and ²D NMR spectra were collected on a Bruker Avance-500 spectrometer with TMS as an internal standard (Bruker, Fällanden, Switzerland). HRESIMS spectra were acquired with a Thermo MAT95XP high resolution mass spectrometer (Thermo Fisher Scientific, Bremen, Germany). Silica gel (200–300 mesh, Qingdao Marine Chemical Inc. Qingdao, China) was used for column chromatography. TLC analysis was carried out on silica gel plate (Merck KGaA, Darmstadt, Germany). A Hitachi Primaide [Hitachi Instruments (Dalian) Co., Ltd.] equipped with a diode array detector (DAD) using a semi-preparative YMC ODS C₁₈ column (20 × 250 mm, 5 μm) was used for semi-preparative HPLC separation. All solvents were analytical grade (Guangzhou Chemical Regents Company, Ltd. Guangzhou, China).