*3.1. General Experimental Procedures*

Melting points were acquired through an SGW X-4 micro-melting-point apparatus (Shanghai Shenguang Instrument Co. Ltd, Shanghai, China). Optical rotations were measured using an Optical Activity AA-55 polarimeter (Optical Activity Ltd., Cambridgeshire, UK). UV spectra were determined by a PuXi TU-1810 UV-visible spectrophotometer (Shanghai Lengguang Technology Co. Ltd., Shanghai, China), and ECD spectra were obtained with a JASCO J-715 spectropolarimeter (JASCO, Tokyo, Japan). NMR spectra were recorded on a Bruker Avance 500 spectrometer (Bruker Biospin Group, Karlsruhe, Germany), using solvent chemical shifts (DMSO-*d*6: δH/δ<sup>C</sup> 2.50/39.52) as reference. HR-ESI-MS were measured on an API QSTAR Pulsar 1 mass spectrometer (Applied Biosystems, Foster, Waltham, MA, USA). Analytical and semi-preparative reversed-phase HPLC separations were performed by a Dionex HPLC system, equipped with P680 pump (Dionex, Sunnyvale, CA, USA), ASI-100 automated sample injector, and UVD340U multiple wavelength detector controlled by Chromeleon software (version 6.80). Commercially available Lobar LiChroprep RP-18 (40–63 μm, Merck, Darmstadt, Germany), Si gel (200–300 mesh, Qingdao Haiyang Chemical Co., Qingdao, China), and Sephadex LH-20 (Pharmacia, Pittsburgh, PA, USA) were used for column chromatography. Thin-layer chromatography (TLC) was carried out using precoated Si gel GF254 plates (Merck, Darmstadt, Germany). All solvents used were distilled prior to use.
