Uv 2550 spectrometer

Thin-layer chromatography (TLC) was performed on silica gel GF254 (Qingdao Haiyang Chemical Co., Ltd, China) and column chromatography was performed with silica gel (60–80, 200–300 mesh, Qingdao Haiyang Chemical Co.). Sephadex LH-20 (Merck, Germany). The ESI-MS spectra were measured with a VG Auto-3000 Spectrometer, Sephadex LH-20 (Merck, Germany) and MS-C18 column (3.5 μm, 4.6 by 150 mm, Waters). Nuclear Magnetic Resonance (NMR) spectra were obtained on a Bruker AV-500 spectrometer with tetramethylsilane (TMS) as an internal standard. Infrared Spectroscopy (IR) spectra were recorded on a Nicolet 380 FT-IR instrument, as KBr pellets (Thermo, Pittsburgh, PA, USA). UV spectra were obtained on a Shimadzu UV-2550 spectrometer (Beckman, Brea, CA, USA).

Optical rotations were measured with a Rudolph Autopol I polarimeter (Rudolph, Hackettstown, NJ, USA). UV spectra were recorded on a Shimadzu UV-2550 spectrometer (Beckman, Kyoto, Japan). ECD spectra were measured on a JASCO J-715 spectrophotometer (JASCO, Tokyo, Japan). IR absorptions were obtained on a Nicolet 380 FT-IR instrument (Thermo, Pittsburgh, PA, USA) using KBr pellets. HRESIMS were determined by an API QSTAR Pulsar mass spectrometer (Bruker, Bremen, Germany) or 6200 series TOF/6500 series (Agilent, Palo Alto, CA, USA). The NMR spectra were recorded on Bruker Avance 500 NMR spectrometers (Bruker, Bremen, Germany), using TMS as an internal standard. HPLC purifications were performed on an analytical reversed-phase column (YMC-packed C₁₈, 250 mm × 10 mm, 5 µm) (YMC, Tokyo, Japan) using a G1311C 1260 Quat Pump VL and detected with a G1315D 1260 DAD VL detector (190–500 nm) (Agilent Technologies 1260 infinity, Palo Alto, CA, USA). Column chromatography was performed with silica gel (60–80, 200–300 mesh, Qingdao Haiyang Chemical Co., Ltd., Qingdao, China), ODS gel (20–45 µm, Fuji Silysia Chemical Co., Ltd., Durham, NC, USA), and Sephadex LH-20 (Merck, Darmstadt, Germany). TLC was carried out on NUSCRIPT silica gel GF254 (Qingdao Haiyang Chemical Co., Ltd., China), and peaks were detected by spraying with 5% H₂SO₄ in EtOH followed by heating.