Waters xselect csh

The NMR spectra were recorded on a Varian VNMRS 600 spectrometer (Varian, Palo Alto, USA, 600 MHz for 1 H) and Varian 400-MR spectrometer (Varian, Palo Alto, USA, 400 MHz for 1 H) with TMS as an internal reference. The carbon signal of solvent (CD 3 OD, 49.00 ppm) was used as a reference for 13 C NMR shifts. ESI-MS spectra were measured using a Bio-TOF Q spectrometer (QStar Elite Hybrid LC/MS/MS). Analytical HPLC was carried on a Dionex UltiMate 3000 instrument (Thermo, Waltham, MA, USA) with UV detection using Waters XSELECT TM CSH TM on C 18 (4.6 × 250 mm, 5 µm) column. Semi-preparative HPLC was conducted on a Shimadzu LC-20A instrument (Shimadzu Corporation, Kyoto, Japan) with UV detection using a Waters XSELECT TM CSH TM on C 18 (10 × 250 mm, 5 µm, Waters Co., Milford, MA, USA) column. Silica gel (200-300 mesh, Jiangyou silica gel Development Co. Ltd., Yantai, China), ODS (Merck, Germany) and Sephadex LH-20 (GE, Sweden) were used for column chromatography. Solvents were analytical grade (Baishi Chemical Co. Ltd., Tianjin, China) for column chromatography and HPLC grade (Merck, Germany) for HPLC analysis. B16 melanoma cells line were acquired from the Chinese Academy of Sciences (Beijing, China) .