Sample Set Information
|Title||Combination of Liquid Chromatography−Fourier Transform Ion Cyclotron Resonance-Mass Spectrometry with 13C‑Labeling for Chemical Assignment of Sulfur-Containing Metabolites in Onion Bulbs|
|Description||We provide a chemical assignment strategy for S-metabolites using 12C- and 13C-based MS and tandem mass spectrometry (MS/MS) spectra recorded by Fourier transform ion cyclotron resonance-mass spectrometry (FTICR-MS) coupled with liquid chromatography (LC) as a case study of the metabolite of onion bulbs. We performed comprehensive peak picking using the theoretical mass difference (1.99579 Da) between 32S-containing monoisotopic ions and their 34S-substituted counterparts for 67 S-containing monoisotopic ions. From these, we identified the specific elemental composition of 22 ions. Finally, we determined that six ions were derived from S-alk(en)ylcysteine sulfoxides and glutathione derivatives.|
|Authors||Ryo Nakabayashi, Yuji Sawada, Yutaka Yamada, Makoto Suzuki, Masami Yokota Hirai, Tetsuya Sakurai, and Kazuki Saito|
|Reference||Nakabayashi R et al. (2013) Analytical Chemistry 85: 1310-1315|
|Comment||The metadata is prepared by the Metabolonote administrator (Sakurai N).|
Analytical Method Details Information
|Title||LC-FTICR-MS Analysis (Positive)|
|Instrument||LC, Agilent 1200 series (Agilent); MS, Solarix 7.0T (Bruker Daltonics)|
|Description|| Extraction of Metabolites:
The freeze-dried samples were extracted with 50 uL of 80% MeOH containing 2.5 uM lidocaine per mg dry weight using a mixer mill (MM300, Retsch) with zirconia beads for 10 min at 20 Hz and 4C. After centrifugation for 10 min, the supernatant was filtered using and HLB uElution plate (Waters).
A liquid sample (1 uL) was analyzed using LC-FTICR-MS (LC, Agilent 1200 series; MS, Bruker Daltonics solarix 7.0 T). Analytical conditions were as follows. LC: column, Xselect CSH C18 (3.5 um, 2.1 mm x 150 mm, Waters); solvent system, solvent A (water with 0.1% formic acid) and solvent B (acetonitrile with 0.1% formic acid); gradient program, 99.5% A/0.5% B at 0 min, 0.5% A/99.5% B at 30.0 min, 0.5% A/99.5% B at 45.min, 99.5% A/0.5% B at 45.1 min, and 99.5% A/0.5% B at 60.0 min; flow rate, 0.3 mL/min; column temperature, 35 C; wavelength, 200-600 nm; MS detection (resolution 260000 at m/z 400); polarity, positive; calibrant, low concentration TuningMix (Agilent); lock mass target, diethylhexylphthalate (C24H38O4, [M+H]+ m/z 391.28429); MS/MS detection (resolution 35000 at m/z 400).