Solvent degasser

Optical rotations were measured on a JASCO DIP-1000 polarimeter, with a Na (589 nm) lamp and filter. ¹H, ¹³C, and 2D NMR spectra were recorded on a Bruker Avance 500 spectrometer at 500 and 125 MHz, respectively, using CD₃OD and DMSO-d₆. Low resolution electrospray mass spectrometry (LRESIMS) and high resolution electrospray mass spectrometry (HRESIMS) experiments were carried out on the Thermo LTQ Orbitrap Discovery system. HPLC separations were performed using an Agilent 1100 liquid chromatography system equipped with a solvent degasser, quaternary pump, and diode array detector (Agilent Technologies, Waldbronn, Germany) and a semipreparative reversed phase column Luna C18, 5 µm, 100 Å, 250 × 10 mm. Precoated silica gel plates (Merck, Kieselgel 60 F254, 0.25 mm) were used for TLC analysis, and the spots were visualized under a UV light (254 nm) or by heating the plate pretreated with H₂SO4/H₂O/AcOH (1:4:20).

Optical rotations were measured in a JASCO DIP-1000 polarimeter (JASCO, Tokyo, Japan), with a Na (589 nm) lamp and filter. ¹H, ¹³C and 2D NMR spectra were recorded in a Bruker Avance 500 spectrometer, at 500 and 125 MHz, respectively, with CD₃OD and D₂O as solvents. HRESIMS experiments were performed in an Applied Biosystems QSTAR Elite system or a Thermo MAT95XP spectrometer. HPLC separations were performed in the Agilent 1100 liquid chromatography system equipped with a solvent degasser, quaternary pump, and diode array detector (Agilent Technologies, Waldbronn, Germany) with a semipreparative reversed phase column (Luna C18: 5 μ, 100 Å, 250 × 10 mm, Phenomenex, Lane Cove, Australia). Precoated silica gel plates (Merck, Kieselgel 60 F254, 0.25 mm, Merck Millipore, Merck KGaA, Darmstadt, Germany) were used for TLC analysis and the spots were visualized under a UV light (254 nm) or by heating the plate pretreated with H₂SO₄/H₂O/AcOH (1:4:20).