**4. Materials and Methods**

#### *4.1. General Experimental Procedures*

Ultraviolet (UV) spectra were recorded on a Shimadzu UV-2401 PC UV-Visible spectrophotometer. ECD spectra were recorded on an Applied PhotoPhysics Chirascan. IR spectra were recorded on Bruker Tensor27 spectrometer. Optical rotations were measured with JASCO P-1020. 1D and 2D NMR spectra were recorded in DMSO-*d*<sup>6</sup> and CD3OD-*d*<sup>4</sup> on Bruker DRX-500. Chemical shifts (δ) were expressed in ppm with reference to the solvent signals. High resolution mass spectra were recorded on a Thermo Instruments MS system (LTQ Orbitrap) equipped with a Thermo Instruments HPLC system with a Thermo Hypersil GOLD column (150 × 4.6 mm) with electrospray ionization in the positive-ion mode. Analytical HPLC was performed on a Waters 2998 with a photodiode array detector (PDA) detector with a Phenomenex Gemini (C18 250 × 4.6 mm) column. Semi-preparative HPLC was carried out on an Agilent 1260 Infinity with a diode array detector (DAD) with an Agilent Zorbax SBC18 (250 × 9.4 mm) column. Sephadex LH-20 (Shanghai kayon Biological Technology) was used for column chromatography.
