Sample Set Information
| ID
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TSE14
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| Title
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Chemical Assignment of Structural Isomers of Sulfur-Containing Metabolites in Garlic by Liquid Chromatography−Fourier Transform Ion Cyclotron Resonance−Mass Spectrometry
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| Description
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BACKGROUND:
The chemical assignment of metabolites is crucial to understanding the relation between food composition and biological activity.
OBJECTIVE:
This study was designed to detect and chemically assign sulfur-containing metabolites by using LC-Fourier transform ion cyclotron resonance-mass spectrometry (FTICR-MS) in Allium plants.
METHODS:
Ultrahigh resolution (>250,000 full width at half-maximum) and mass accuracy (<1 mDa) by FTICR-MS allowed us to distinguish ions containing sulfur isotopes ((32)S and (34)S).
RESULTS:
Putative 69 S-containing monoisotopic ions (S-ions) were extracted from the metabolome data of onion (Allium cepa), green onion (Allium fistulosum), and garlic (Allium sativum) on the basis of theoretical mass differences between (32)S-ions and their (34)S-substituted counterparts and on the natural abundance of (34)S. Eight S-ions were chemically assigned by using the reference data according to the guidelines of the Metabolomics Standards Initiative. Three ions detected in garlic were assigned as derived from the isomers γ-glutamyl-S-1-propenylcysteine and γ-glutamyl-S-2-propenylcysteine and as S-2-propenylmercaptoglutathione on the basis of differences in key product ions identified in reference tandem MS spectra.
CONCLUSION:
The ability to discriminate between such geometric isomers will be extremely useful for the chemical assignment of unknown metabolites in MS-based metabolomics.
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| Authors
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Ryo Nakabayashi, Yuji Sawada, Morihiro Aoyagi, Yutaka Yamada, Masami Yokota Hirai, Tetsuya Sakurai, Takahiro Kamoi, Daryl D Rowan, Kazuki Saito
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| Reference
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Nakabayashi et al. (2016) The Journal of Nutrition.13:397S–402S
doi: 10.3945/jn.114.202317.
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| Comment
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The raw files were converted to netCDF files and stored in DROP Met as "Metabolome data in Allium plants and MS/MS spectra of S-containing compounds"
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The raw data files are available at DROP Met web site in PRIMe database of RIKEN.
