Agilent 1200 lc msd trap spectrometer

The NMR spectra were recorded using a BRUKER AVANCE III 600 (Bruker Biospin GmbH, Karlsruhe, Germany), with tetramethylsilane (TMS) as an internal standard. The ESI-MS spectra were obtained by using an Agilent 1200 LC-MSD Trap spectrometer (Agilent, Santa Clara, CA, USA). Preparative HPLC was performed using a GILSON 321 pump, 151 UV/VIS detector (Gilson, Villiers-le-Bel, France), and RS Tech HECTOR-M C18 column (5 micron, 250 × 21.2 mm, RS Tech Crop, Chungju, South Korea). Column chromatography was performed using a silica gel (Kieselgel 60, 70–230, and 230–400 mesh, Merck, Darmstadt, Germany), YMC C-18 resins, and thin-layer chromatography (TLC) was performed using pre-coated silica-gel 60 F254 and RP-18 plates (both 0.25 mm, Merck, Germany), and the spots were detected under UV light and using 10% H₂SO₄.

The optical rotation values were confirmed using a JASCO DIP-370 digital polarimeter (Hachioji, Tokyo, Japan). Electrospray ionization (ESI) mass spectra were obtained using an Agilent 1200 LC-MSD Trap spectrometer. LC-MS/MS analyses were performed using a Shimadzu LCMS-8040 system (Kyoto, Japan) in positive and negative mode. NMR spectra were analyzed on a JEOL ECA 400 and 600 spectrometer (JEOL Ltd, Tokyo, Japan) with TMS used as an internal standard. Sephadex LH-20 (GE Healthcare Bio-Science AB, Uppsala, Sweden) and Diaion HP-20 (Supelco, Bellefonte, PA, USA) resins were used. Thin layer chromatography (TLC) using YMC RP-18 resins was performed using pre-coated silica gel 60 F₂₅₄ and RP-18 F_254S plates (both 0.25 mm, Merck, Darmstadt, Germany), and the spots were detected under UV light at 254 and 365 nm wavelengths and using 10% H₂SO₄, followed by heating for 3–5 min. The chemicals used were purchased from commercial suppliers and used as received. All chemical reagents were purchased from Sigma-Aldrich (St. Louis, MO, USA).