*3.1. General Procedures*

Optical rotations were obtained on a JASCO P-2200 digital polarimeter (JASCO Co., Tokyo, Japan). UV spectra were recorded on a Hitachi U-3900H spectrophotometer (Hitachi, Ltd., Tokyo, Japan). NMR spectra were measured by a Bruker AVANCE-500 instrument (Bruker, Billerica, MA, USA) using tetramethylsilane as an internal standard. HRESIMS were recorded on a Waters LCT PREMIER 2695 (Waters Co., Milford, MA, USA) and a JEOL JMS-T100LP (JEOL, Ltd., Tokyo, Japan). Column chromatography was performed with silica gel 60 N (Kanto Kagaku, Tokyo, Japan) and Diaion HP-20 (Mitsubishi Chemical, Tokyo, Japan). Medium pressure liquid chromatography (MPLC) was carried out on Toyopearl HW-40F (TOSOH Co., Tokyo, Japan), MCI gel CHP20P (Mitsubishi Chemical, Tokyo, Japan), and Biotage SNAP Cartridge KP-C18-HS (Biotage, Uppsala, Sweden).
