V 520 uv vis spectrophotometer

Optical rotations were determined on a P-1030 digital polarimeter (JASCO, Tokyo, Japan). IR spectra were measured on a FT-710 Fourier transform infrared spectrophotometer (Horiba, Kyoto, Japan), while UV spectra were taken on a V-520 UV/Vis spectrophotometer (JASCO, Tokyo, Japan). NMR data were obtained by an Ultrashield 600 spectrometer (Bruker, Ettlingen, Germany) with tetramethylsilane (TMS) as an internal standard. Positive ion HR-ESI-MS measurement was performed with the LTQ Orbitrap XL mass spectrometer (Thermo Fisher Scientific, Waltham, MA, USA). Column chromatography (CC) was carried out on silica gel 60 (E. Merck, Darmstadt, Germany), and octadecyl silica (ODS) gel (Cosmosil 75C18-OPN (NacalaiTesque, Kyoto, Japan; Φ = 35 mm, L = 350 mm). HPLC was performed on ODS gel (Inertsil ODS-3, GL-science, Φ = 6 mm, 250 mm, flow rate = 1.6 mL/min, GL Sciences, Tokyo, Japan), and the eluate was observed by refractive index detector with the RI-930 intelligent detector (JASCO, Tokyo, Japan) and a PU-1580 intelligent pump (JASCO, Tokyo, Japan). All chemicals were purchased from Wako Pure Chemical Industries, Ltd. (Osaka, Japan) and TCI (Tokyo, Japan).

¹H and ¹³C-NMR spectra were taken on a Bruker Ultrashield Avance 600 spectrometer at 600 MHz and 150 MHz, respectively, with TMS as an internal standard. IR and UV spectra were measured on a HORIBA FT-720 FT-IR spectrophotometer and JASCO V-520 UV–vis spectrophotometer, respectively. Optical rotation was measured on a JASCO P-1030 digital polarimeter. Positive ion HR-ESI-MS was recorded using an LTQ Orbitrap XL mass spectrometer (Thermo Fisher Scientific, Waltham, MA, USA). Silica gel open column chromatography (CC) and reversed-phase (ODS) CC were performed on silica gel 60 (E. Merck, Darmstadt, Germany), and Cosmosil 75C18-OPN (Nacalai Tesque, Kyoto, Japan; Φ = 35 mm, L = 350 mm), respectively. HPLC was performed on an ODS column (Inertsil ODS-3, GL Science, Tokyo, Japan; Φ = 6 mm, L = 250 mm, 1.5 mL/min), and the eluate was monitored with a JASCO RI-930 intelligent detector and a JASCO PU-1580 intelligent pump unless otherwise specified.