Maxis 2 etd q tof mass spectrometer

The UHPLC–MS/MS
analysis
was performed in a Maxis II ETD Q-TOF mass spectrometer (Bruker Daltonics,
Germany) using an electrospray ionization (ESI) source with either
an Elute UHPLC (Bruker Daltonics, Germany) or a 1260 Infinity II Binary
Pump (Agilent Technologies, USA) system. The separation was performed
on an Acquity UPLC HSS T3 column (1.8 μm, 100 × 2.1 mm)
from Waters Corporation. Milli-Q water with 0.1% formic acid was used
as mobile phase A, and LC–MS grade methanol with 0.1% formic
acid was used as mobile phase B. The column temperature was kept at
40 °C, and the autosampler temperature was kept at 4 °C.
The flow rate was set to 0.22 mL/min with an injection volume of 5
μL. The gradient used was as follows: 0–2 min, 0% B;
2–15 min, 0–100% B; 15–16 min, 100% B; 16–17
min, 100–0% B; 17–23 min, 0% B. The system was controlled
using the Compass HyStar software package from Bruker (Bruker Daltonics,
Germany). High-resolution mass spectra were acquired in negative mode
at a mass range of m/z 50–1200.
Data acquisition was performed in AutoMSMS mode (data-dependent acquisition,
DDA) with a cycle time of 0.5 s and a ramped collision energy from
20 to 50 eV. A solution of sodium formate [10 mM in a mixture of 2-propanol/water
(1/1, v/v)] was used for internal calibration at the beginning of
each run, in a segment between 0.10 and 0.31 min.

NMR spectra were acquired at 25 °C on a Bruker Avance HDX 800 MHz spectrometer (Zürich, Switzerland) equipped with a TCI cryoprobe. The ¹H and ¹³C chemical shifts were referenced to the DMSO-d6 solvent peaks at δ_H 2.50 and δ_C 39.52 ppm, respectively, and all deuterated solvents were from Cambridge Isotope Laboratories (CIL). Low resolution mass spectra were measured with a Thermo Ultimate 3000 system equipped with an Accucore^TM C18 column (2.6 μm, 150 × 2.1 mm), a diode-array detector (DAD), and an ESI mass spectrometer. HRESIMS measurements were obtained on a Bruker Maxis II ETD QTOF mass spectrometer (Bremen, Germany) and was calibrated with sodium trifluoroacetate. SINGLE StEP Silica Column™ and Sephadex LH-20 (GE Healthcare BioSciences AB) were used for fractionation. Reverse phase HPLC was performed on Thermo Ultimate 3000 system separation module with a Dionex^TM diode array detector (MA, USA). Optical rotations were determined on a Jasco P-1020 Polarimeter (10 cm cell) (Tokyo, Japan). All solvents used for extraction, chromatography, [α]_D, and MS were Honeywell Burdick & Jackson HPLC grade (Muskegon, MI, USA), 0.1% formic acid (Sigma-Aldrich) was used in solvent system for LC-MS and 0.1% TFA (Sigma-Aldrich) was used in solvent system for HPLC. H₂O was purified with Sartorius Arium^®Pro VF ultrapure water system (Göttingen, Germany).