Avance hd 800 mhz nmr spectrometer

Optical rotation was obtained using a JASCO P-1020 polarimeter. UV spectra were recorded on an Optizen 2120 UV spectrophotometer. NMR experiments were operated on a Bruker AVANCE HD 800 MHz NMR spectrometer (Bruker, Germany) at the Korea Basic Science Institute (KBSI) in Ochang, Korea. NMR spectra were recorded in DMSO-d₆ as an internal standard (δ_H 2.50/δ_C 39.51). High resolution electrospray ionization mass spectra (HR-ESIMS) were recorded on a Waters Vion IM-QTOF mass spectrometer (Waters, USA) at the KRIBB in Ochang, Korea. Column chromatography was performed on reversed phase silica gel (0.075 mm; Cosmosil, Japan). Analytical C₁₈ (Waters Sunfire, 5 μm, 4.6 × 150 mm) and semi-preparative C₁₈ (Waters Atlantis T3, 5μm, 10 × 250 mm) columns were used for reverse phase HPLC on a 515 pump HPLC system (Waters) equipped with a 2996 PDA detector (Waters) using HPLC grade solvents (Honeywell). Liquid chromatography-mass spectrometry (LC-MS) was operated using an LTQ XL linear ion trap (Thermo Scientific, USA) equipped with an electrospray ionization (ESI) source that was coupled to a rapid separation LC (RSLC; ultimate 3000, Thermo Scientific) system (ESI-LC-MS).

Two distinctive peaks with MSTN-inhibitory capacity were identified using the reverse-phase HPLC separation. To identify the molecular structures of the compounds, LC-MS and NMR experiments were carried out. Liquid chromatography-mass spectrometry (LC-MS) was operated with an LTQ XL linear ion trap (Thermo Scientific, Rockford, IL, USA) equipped with an electrospray ionization (ESI) source that was coupled to a rapid separation LC (RSLC; Ultimate 3000, Thermo Scientific) system (ESI-LC-MS). NMR experiments were operated on the Bruker AVANCE HD 800-MHz NMR spectrometer (Bruker, Berlin, Germany) at the Korea Basic Science Institute (KBSI) in Ochang, Korea. NMR spectra were recorded in CD₃OD as an internal standard (δ_H 3.31/δ_C 49.0).