Spherisorb silica

Optical rotations were measured in CHCl₃ or MeOH at 25 °C using a Perkin-Elmer 241 polarimeter. UV spectra were recorded on a GBC Cintra 5 spectrophotometer. NMR spectra of all isolated compounds were recorded at 25 °C on Unity Inova 500NB high-resolution spectrometer (Agilent Technologies, CA, USA) operating at 500 MHz for ¹H-NMR and 100 MHz for ¹³C-NMR, respectively. Spectra were measured in CDCl₃ and CD₃OD and referenced against residual non-deuterated solvents. HRESIMS were measured on an Agilent 6520 Time of Flight (TOF) MS instrument. Column chromatography was carried out under TLC monitoring using silica gel (40–63 µm, Merck), and Sephadex LH-20 (25–100 µm, Pharmacia). For vacuum-liquid chromatography (VLC), silica gel (40– 63 µm) (Merck) was used. TLC was performed on silica gel 60 F₂₅₄ or RP-18 F₂₅₄ (Merck). LiChrolut RP-18 (40–63 μm) 500 mg, 3 mL (Merck) solid phase extraction (SPE) cartridges were also used. Semi-preparative HPLC was conducted by means of a Varian 920 LH instrument fitted with an autosampler module with a 1000 µL loop. The peak purities were monitored using a dual-wavelength UV detector settled at 254 and 360 nm. The columns were a 250 × 10 mm Spherisorb silica, particle size 5 µm (Waters) and a 300 × 7.5 mm Polymeric Reversed Phase (PLRP-S 100 Å), particle size 8 µm (Varian).