Kiesel gel 60 rp 18f254s

Analysis of NMR spectra was carried out through Varian UNITY 400 (Varian, Inc., Palo Alto, CA) FT-NMR spectrometer using the tetramethylsilane as an internal standard. Waters Q-Tof Premier spectrometer (Micromass UK Ltd., Manchester, UK) was used to obtain HR-ESI mass spectra. Sephadex LH-20 (25–100 µm, Sigma-Aldrich, Steinheim, Germany), silica gel (230–400 mesh, SiliCycle Inc., Quebec, Canada), and RP-C18 (Cosmosil 40C₁₈-PREP, Kyoto, Japan) were used for column chromatography. Thin layer chromatography (TLC) was performed on precoated Kiesel-gel 60 F₂₅₄ (0.25 mm, Merck, Darmstadt, Germany) and Kiesel-gel 60 RP-18F_254s (0.25 mm, Merck, Steinheim, Germany). HPLC analysis was conducted on Thermo Dionex Ultimate 3000 equipped with Ultimate 3000 pump, autosampler, column compartment and diode array detector and Agilent Technology model 1260 Infinity equipped with 1260 DAD. Columns used for the analysis were YMC Trait C18 ExRS (5 µm, 4.6 × 250 mm), Phenomenex synergy RP-Polar (5 µm, 4.6 × 250 mm), Thermo acclaim polar advantage (5 µm, 4.6 × 250 mm), and Atlantis T3 (5 µm, 4.6 × 250 mm). Preparative HPLC was carried out with a model Gilson PLC 2020. Preparative columns were Thermo acclaim polar advantage (5 µm, 21.2 × 250 mm), Atlantis (5 µm, 19 × 250 mm), and YMC Trait C18 ExRS (5 µm, 20 × 250 mm).

The NMR experiments were performed using a JNM-ECA 500 MHz NMR instrument (JEOL Ltd., Tokyo, Japan). HRESIMS was carried out on a JMS-700 MStation Mass Spectrometer (JEOL Ltd., Tokyo, Japan). UV spectra were recorded on an Evolution 260 Bio UV–Visible spectrophotometer (Thermo Fischer Scientific, Waltham, MA, USA). Thin-layer chromatographic (TLC) analysis was performed on Kieselgel 60 F254 (Merck, Darmstadt, Germany) and Kieselgel 60 RP-18 F254S (Merck), with visualization performed under UV light (254 and 365 nm) and 10% (v/v) sulfuric acid spray followed by heating (200 °C, 2 min). YMC Gel ODS-A (12 nm, S-150 μm; YMC Co., Kyoto, Japan) was used for column chromatography (CC). Preparative HPLC was performed using a Gilson Preparative HPLC system (Gilson Inc., Middleton, WI, USA) equipped with YMC Pack Pro C18 (5 μm, 250 × 20 mm, YMC Co.). Analytical HPLC was performed using an Agilent 1100 series system (Agilent Technologies, Palo Alto, CA, USA) equipped with YMC-Triart C18 (5 μm, 250 × 4.6 mm, YMC Co.). A [⁶⁰Co] γ-irradiator (150 TBq capacity; AECL, Ottawa, Canada) was used for gamma irradiation. All other chemicals and solvents used in this study were of analytical grade.