Mplc system

For thin layer chromatography (TLC) analysis, a TLC precoated silica gel 60 F₂₅₄ (No. 5715; Merck Co., Darmstadt, Germany) was used. We used silica gel (No. 7734; Merck Co.) as the stationary phase for repeated column chromatography. A medium-pressure liquid chromatography (MPLC) system (Biotage, Uppsala, Sweden) was used; it was equipped with KP-SIL cartridges (39 mm × 225 mm; Biotage). The HPLC analysis was conducted using the Waters 1525 Binary HPLC Pump (Waters, Miami, FL, USA), which was equipped with a UV/visible spectroscopy detector (model 2489; Waters, Miami, FL, USA). The water and acetonitrile were of HPLC grade, and all other reagents were of analytical grade.

n-Hexane, n-butanol (n-BuOH), ethyl acetate (EtOAc), chloroform (CHCl₃), ethanol (EtOH), and pyridine-d₅ (MA, USA) were obtained from SamChun Pure Chemical Co., Korea. Fast atom bombardment mass was conducted using a JEOL JMS-AX505WA (Jeol, Japan), mass spectrometer. A high-resolution LC/MS/MS analysis was done in a Xevo G2 Q-TOF LC/MS/MS system (Waters, USA) using an ACQUITY UPLC I Class system (Dionex). The ¹H- and ¹³C-NMR spectra were checked with a Bruker Avance 500 NMR spectrophotometer (Bremen, Germany) with trimethylsilane (TMS), the internal standard. Thin-layer chromatography (TLC) was conducted on Kiesel gel 60 F₂₅₄ (250-μm) silica gel plate (Art. 5715, Merck Co., Darmstadt, Germany), and visualized by a 10% H₂SO₄ spraying in a methanol (MeOH) solution. Accordingly, CC was performed with a LiChroprep RP-18 (40-63 μm, Merck Co.). An MPLC system (Biotage, Uppsala, Sweden), which was equipped with cartridges (KP-SIL, 39 mm × 225 mm), was used. The sugar determinations were conducted with an HP 5890 series II GC (Hewlett-Packard, Avondale, PA, USA) using an HP-5 capillary column (30 m × 0.32 mm i.d., 0.25-μm film thickness; Agilent, J&W Scientific, Folsom, CA, USA; injector temperature: 200°C; detector temperature: 200°C; column temperature: 230°C; and flow rate of He gas: 1 mL/min).