Sb c18 column

The HR-ESI-MS data were obtained on an Agilent 6520B Q-TOF spectrometer. The optical rotation was determined on a JASCO P-1020 polarimeter. Analytical HPLC measurements were conducted on a Shimadzu LC-20AT pump with a Shimadzu SPD-20A UV-Vis detector, using a ZORBAX SB-C18 column (250×4.6 mm, 5 μm). Semi-preparative HPLC separation was performed on a Shimadzu LC-6AD pump with a Shimadzu SPD-20A UV-Vis detector, using a ZORBAX SB-C18 column (250×9.4 mm, 5 μm). NMR spectra were recorded on a Bruker ACF (300 and 500 MHz) spectrometer with deuterated solvent signals used as internal standards. Column chromatography was conducted on MCI gel (75–150 μm; Mitsubishi Chemical Corp., Tokyo, Japan), ODS (PrePAK-500/C18, YMC) and Sephadex LH-20 (20–100 μm, Pharmacia, U.S.A.) columns.

Optical rotations at the sodium D line were measured with a Perkin-Elmer 241 digital polarimeter using a quartz cell with a path length of 100 mm at room temperature. Concentrations (c) are given in g/100 mL. IR spectra were measured on a Nicolet 380 Fourier Transform Infrared Spectrometer and analyzed with OMNIC software. UV spectra were collected on a Shimadzu UFLC system with a photodiode array detector. The ECD spectra were obtained on a JASCO J-810 spectrometer. NMR spectra were recorded on a Bruker AV-400HD spectrometer. All chemical shifts were quoted on the δ scale in ppm using residual solvent as the internal standard (methanol: δ_H 3.31 for ¹H NMR, δ_C 49.00 for ¹³C NMR; chloroform: δ_H 7.26 for ¹H NMR, δ_C 77.16 for ¹³C NMR). Coupling constants (J) are reported in Hz. For HPLC purification, a C₁₈ semi-preparative HPLC column (Agilent SB-C18 column, 250 × 9.4 mm, 5 μm) and a Shimadzu UFLC system were used. HRESIMS were measured on a Waters SYNAPT hybrid quadrupole/time of flight spectroscopy using positive electrospray ionization. Human melanoma cancer cells MDA-MB-435, human breast cancer cells MDA-MB-231, and human ovarian cancer cells OVCAR3 were purchased from the American Type Culture Collection (Manassas, VA). Molecular models in Figure 2 were generated by Chem3D Pro 19.0 using MM2 force field calculation.