Sepacore system

Optical rotations were measured using AA-55 polarimeter (Optical Activity, Ramsey, United Kingdom) in CH₂Cl₂. The UV spectra were measured in MeCN on a DU800 UV-vis spectrophotometer (Beckman Coulter, Brea, CA, USA). ¹H- and ¹³C-NMR spectra were recorded at 400 and 100 MHz, respectively, on a WM-400 spectrometer (Bruker, Billerica, MA, USA) in CDCl₃, unless otherwise noted. The same solvent was used as the internal standard. COSY, ROESY, DEPT, HMBC and HMQC experiments [35 ] were recorded using Bruker microprograms. ESI-MS were obtained on a TSQ Quantum Access™ mass spectrometer (Thermo Fisher Scientific, Waltham, MA, USA). Analytical and PTLC were performed on silica gel plates (Kieselgel 60, F254, Merck, Darmstadt, Germany, 0.25 and 0.5 mm, respectively). The spots were visualized exposure to UV radiation (254 nm). Column chromatography was performed on a silica gel (Kieselgel 60, 0.063−0.200 mm, Merck) Reverse phase column chromatography was carried out using a C-18ec Chromabond 10-g cartridge (Macherey-Nagel, Düren, Germany). Medium pressure liquid chromatography (MPLC) was performed with a Sepacore system (Büchi, Flawil, Switzerland) equipped with a UV-detector. Fractionation was performed with a PuriFlash SiHC cartridge (SiOH, 40 g, Interchim, Montluçon, France).

1D and 2D NMR spectra for isolated metabolites were obtained on Bruker DRX 400 MHz spectrometer (Bruker, Massachusetts). HRESIMS data were recorded with Xevo G2-Xs QTof mass spectrometer (Waters Corporation, Milford, MA). Vacuum liquid chromatography (VLC) was performed on silica gel column (40–63 μm; 5 mm × 5.5 mm). Medium pressure liquid chromatography (MPLC) was carried out on Sepacore system (Buchi, Switzerland) using silica gel column (40–63 μm; 15 mm × 920 mm). Solid Phase Extractions (SPE) were performed using Supelclean™ LC-Si SPE cartridges. Semipreparative HPLC was carried out on a Pharmacia LKB 2252 liquid chromatography system equipped with refractive index detector Shodex RI-102, using a Supelcosil column (10 mm × 250 mm × 5 μm, silica).

Melting points were obtained on an X-4 micro melting point apparatus. Optical rotations were measured with a Horiba SEPA-300 polarimeter. IR spectra were obtained with a Tenor 27 spectrophotometer using KBr pellets. 1D and 2D spectra were run on a Bruker Avance III 600 MHz spectrometer with TMS as an internal standard. Chemical shifts (δ) were expressed in ppm with reference to the solvent signals. Mass spectra were recorded on an Agilent 6200 Q-TOF MS system. Column chromatography (CC) was performed on silica gel (200–300 mesh, Qingdao Marine Chemical Ltd., Qingdao, People’s Republic of China), RP-18 gel (20–45 µm, Fuji Silysia Chemical Ltd., Japan), and Sephadex LH-20 (Pharmacia Fine Chemical Co., Ltd., Sweden). Medium Pressure Liquid Chromatography (MPLC) was performed on a Büchi Sepacore System equipping with pump manager C-615, pump modules C-605 and fraction collector C-660 (Büchi Labortechnik AG, Flawil, Switzerland), and columns packed with RP-18 gel. Preparative High Performance Liquid Chromatography (prep-HPLC) was performed on an Agilent 1260 liquid chromatography system equipped with Zorbax SB-C18 columns (5 μm, 9.4 mm × 150 mm or 21.2 mm × 150 mm) and a DAD detector. Fractions were monitored by TLC (GF 254, Qingdao Haiyang Chemical Co., Ltd. Qingdao), and spots were visualized by heating silica gel plates sprayed with 10% H₂SO₄ in EtOH.