*3.1. General Experimental Procedures*

Optical rotations were recorded on a JASCO P-1020 polarimeter (JASCO Corporation, Tokyo, Japan) in MeOH at 25 ◦C. UV spectra were measured using a Shimadzu UV-1800 spectrophotometer (Shimadzu Corporation, Tokyo, Japan). High-resolution electrospray ionization (HR-ESI-MS) were obtained with an Agilent 6529B Q-TOF instrument (Agilent Technologies, Santa Clara, CA, USA). ECD spectra were carried out with Chirascan circular dichroism spectrometers (Applied Photophysics Ltd., Leatherhead, UK). Both 1D and 2D NMR spectra were acquired on a Bruker AVIII-400 and Bruker AVIII-600 NMR spectrometers with tetramethylsilane (TMS) as an internal standard (Bruker, Karlsruhe, Germany). Preparative high-performance liquid chromatography (Pre-HPLC) was performed utilizing a Shimadzu LC-20 system (Shimadzu, Tokyo, Japan) equipped with a Shim-pack RP-C18 column (20 × 250 mm i.d., 10 μm, Shimadzu, Tokyo, Japan) with a flow rate at 10 mL/min at 25 ◦C, which was recorded by a binary channel UV detector at 210 nm and 254 nm. The analytical chiral HPLC used was a JASCO LC-2000 system equipped with a Daicel Chiralpak AD-H column (4.6 mm × 250 mm, 5 μm) and a CD-2095 chiral detector at 280 nm. The mobile phase was *n*-hexane/isopropanol (80:20, *v*/*v*) used at a flow rate of 0.5 mL/min. Column chromatography (CC) was performed with silica gel (200–300 mesh, Qingdao Marine Chemical Inc., Qingdao, China) and ODS (50 μm, YMC, Kyoto, Japan) on a Flash Chromatograph System (SepaBen machine, Santai Technologies, Changzhou, China). Thin-layer chromatography (TLC) was performed using precoated silica gel GF254 plates (Qingdao Marine Chemical Inc., Qingdao, China).
