Vxr 300 spectrometer

All reagents, unless otherwise stated, were provided by Sigma-Aldrich Co (St. Louis, MO, USA). Thin layer chromatography-polyethylene terephthalate (TLC-PET) foils with fluorescent indicator 254 nm were used. Chromatographic columns were performed on silica gel using column chromatography (Merck 60, 230-400 mesh ASTM silica gel, Merck KGaA, Darmstadt, Germany). Nuclear magnetic resonance (NMR) spectra were recorded with a Varian VXR-300 spectrometer (Varian Medical Systems, Inc., Palo Alto, CA, USA). Mass spectra were obtained using electrospray ionization (ESI) in positive mode with an LCQ (Thermo Finnigan) ion trap mass spectrometer (San Jose, CA, USA) equipped with an electrospray ionization (ESI) source. Analyses indicated by the symbols of the elements or functions were within ± 0.4% of the theoretical values. Purity and chemical structures of SP1–6 were confirmed using HPLC, and ¹H-, ¹³C-NMR, and MS spectra (Supplementary MaterialsSP1–6), respectively.

All reagents and solvents, unless differently stated, were used as received from Sigma Aldrich (St. Louis, MO, USA). Chromatography was performed on silica gel (Merck 60, 70–230 mesh); homogeneity was confirmed by TLC on silica gel Merck 60 F₂₅₄ (Sigma Aldrich, St. Louis, MO, USA). ¹H- and ¹³C-NMR spectra were recorded on a Varian VXR-300 spectrometer (Varian Inc., Palo Alto, CA, USA). The LC-MS/MS system used consisted of an LCQ ion trap mass spectrometer (Thermo Finnigan, San Jose, CA, USA) equipped with an electrospray ionization (ESI) source. HR-MS spectra were recorded using Q Exactive™ Hybrid Quadrupole-Orbitrap™ Mass Spectrometer (Thermo Fischer Scientific, Waltham, MA, USA) coupled with HPLC Dionex series Ultimate 3000 (Thermo Fischer Scientific, Waltham, MA, USA) and a Phenomenex Luna 5µ C18 150 mm × 2 mm (P/N° 00F-4041-B0) column. Mass resolution was set at 140,000, and the scan range was from 250–750 m/z (Table S1).