Uhr qtof maxis 4g mass spectrometer

A Perkin-Elmer-241 MC polarimeter was used to measure optical rotations. ECD spectra were recorded on a J-810 spectropolarimeter. One- and two-dimensional NMR spectra were recorded on a Bruker ARX 600 spectrometer. Mass spectra (ESI) were recorded with a Finnigan LCQ Deca mass spectrometer. A UHR-QTOF maxis 4G mass spectrometer (Bruker Daltonics) was used to record HRESIMS data. A Dionex UltiMate-3400SD system with a LPG-3400SD pump and a photodiode array detector (DAD 3000RS) as well as a separation column (Eurosphere-10 C₁₈, 125 × 4 mm, Knauer) were used for HPLC analysis. Detection wave lengths were set at 235, 254, 280, and 340 nm. Semi-preparative HPLC analysis was performed with a Merck Hitachi Chromaster HPLC system (UV detector L7400; pump L7100; column Eurosphere-100 C₁₈, 300 × 8 mm, Knauer; flow rate at 5 mL/min). Silica gel 60 M (0.04–0.063 mm, Macherey-Nagel) or Sephadex LH-20 were used for column chromatography. TLC plates precoated with silica gel F₂₅₄ (Merck) were used to monitor isolation fractions. Distilled and spectral grade solvents were used for column chromatography and spectroscopic measurements, respectively.

Optical rotations were measured with a Jasco P-2000 polarimeter (JASCO, Tokyo, Japan). Analytical HPLC was performed with a Dionex UltiMate-3400SD system coupled to an LPG-3400SD pump and a DAD300RS photodiode array detector (Dionex Softron, Germering, Germany). The analytical column (125 × 4 mm) was prefilled with Eurosphere-10 C18 (Knauer, Berlin, Germany), following the program: 0 min (10% MeOH); 5 min (10% MeOH); 35 min (100% MeOH); 45 min (100% MeOH). NMR spectra were recorded with Bruker ARX 300 or 600 NMR spectrometers (Bruker, Karlsruhe, Germany). Chemical shifts were referenced to the solvent residual peaks. HRESIMS were recorded on a UHR-QTOF maXis 4G mass spectrometer (Bruker Daltonics, Bremen, Germany). Column chromatography was conducted with Merck MN silica gel 60M (0.04–0.063 mm). TLC plates precoated with silica gel F₂₅₄ (Merck) were used with detection under 254 and 366 nm. Distilled and spectral grade solvents were used for column chromatography and spectroscopic measurements, respectively. Semipreparative HPLC was performed using a Merck Hitachi HPLC System (UV detector L-5410; pump L-5100; Eurosphere-100 C18, 300 × 8 mm), with a mixture of MeOH-H₂O or MeCN-H₂O as mobile phase.