6220 accurate mass tof lc ms system

Optical rotation was measured using a JASCO P-2000 polarimeter (Tokyo, Japan). The NMR spectra were acquired on a 400 MHz Agilent NMR spectrometer (DD2, Santa Clara, CA, USA) using CDCl₃. The HRESIMS was performed on an Agilent 6220 Accurate-Mass TOF LC/MS system. Silica gel (230–400 mesh, Merck KGaA, 64271 Darmstadt, Germany) and RP-18 (YMC gel ODS-A, 12 nm, S-150 μm, YMC Co., Ltd., Kyoto 600-8106, Japan). Thin Layer Chromatography (TLC) analysis was performed on silica gel 60 F254 (0.2 mm thickness, Merck KGaA, 64271 Darmstadt, Germany) and RP-18 F 254_S (Merck KGaA, 64271 Darmstadt, Germany) plates by visualization under UV light at 254 nm, 365 nm, and 10% (v/v) of sulfuric acid followed by heating. Preparative HPLC was performed using an Acme 9000 system (Young Lin, Anyang, Korea) equipped with a YMC-Pack Pro C18 column (5 μm, 250 × 20 mm i.d.).

Optical rotations were measured on a P-1010 polarimeter (JASCO Co., Ltd, Tokyo, Japan) at 20 °C. HR-ESI mass spectrometric analyses were performed with Waters ACQUITY UPLC system coupled to a Micromass Q-Tof Micro mass spectrometer and Agilent 6220 Accurate-Mass TOF LC/MS system. A YMC Pack Pro C18 column (250 mm × 20 mm i.d., YMC Co., Ltd., Kyoto, Japan) was used for preparative HPLC, along with a Waters system composed of a 1525 binary HPLC pump and a 2487 dual wavelength absorbance detector. Silica gel (230–400 mesh, Merck, Darmstadt, Germany), RP-18 (YMC gel ODS-A, 12 nm, S-150 μm), and Sephadex LH-20 (Amersham Pharmacia Biotech, Amersham, UK) was used for column chromatography. Thin-layer chromatographic (TLC) analysis was performed on Kieselgel 60 F 254 (Silica gel, 0.25 mm layer thickness, Merck, Darmstadt, Germany) and RP-18 F 254s (Merck, Darmstadt, Germany) plates, with visualization under UV light (254 and 365 nm) and 10% (v/v) sulfuric acid spray followed by heating (120 °C, 5 min).