scholarly journals Mass Spectrometry-Based Characterization of New Spirolides from Alexandrium ostenfeldii (Dinophyceae)

Marine Drugs ◽  
2020 ◽  
Vol 18 (10) ◽  
pp. 505
Author(s):  
Joyce A. Nieva ◽  
Jan Tebben ◽  
Urban Tillmann ◽  
Sylke Wohlrab ◽  
Bernd Krock
Keyword(s):  
Mass Spectrometry ◽  
High Resolution Mass Spectrometry ◽  
Molecular Ions ◽  
Ring System ◽  
The Other ◽  
Spectral Techniques ◽  
Mass Spectral ◽  
Alexandrium Ostenfeldii ◽  
Different Strains

Spirolides belong to a group of marine phycotoxins produced by the marine planktonic dinophyte Alexandrium ostenfeldii. Composed of an imine moiety and a spiroketal ring system within a macrocylcle, spirolides are highly diverse with toxin types that vary among different strains. This study aims to characterize the spirolides from clonal A. ostenfeldii strains collected from The Netherlands, Greenland and Norway by mass spectral techniques. The structural characterization of unknown spirolides as inferred from high-resolution mass spectrometry (HR-MS) and collision induced dissociation (CID) spectra revealed the presence of nine novel spirolides that have the pseudo-molecular ions m/z 670 (1), m/z 666 (2), m/z 696 (3), m/z 678 (4), m/z 694 (5), m/z 708 (6), m/z 720 (7), m/z 722 (8) and m/z 738 (9). Of the nine new spirolides proposed in this study, compound 1 was suggested to have a truncated side chain in lieu of the commonly observed butenolide ring in spirolides. Moreover, there is indication that compound 5 might belong to new spirolide subclasses with a trispiroketal ring configuration having a 6:5:6 trispiroketal ring system. On the other hand, the other compounds were proposed as C- and G-type SPX, respectively. Compound 7 is proposed as the first G-type SPX with a 10-hydroxylation as usually observed in C-type SPX. This mass spectrometry-based study thus demonstrates that structural variability of spirolides is larger than previously known and does not only include the presence or absence of certain functional groups but also involves the triketal ring system.

High resolution MALDI-TOF-MS and MS/MS: Application for the structural characterization of sulfated oligosaccharides

2019 ◽  
Vol 25 (5) ◽  
pp. 428-436
Author(s):  
David Lesur ◽  
Gilbert Duhirwe ◽  
José Kovensky
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
High Resolution Mass Spectrometry ◽  
Molecular Ions ◽  
Ionization Mass ◽  
Sulfated Oligosaccharides ◽  
Ms Analysis ◽  
Specific Sequences

Sulfated oligosaccharides are involved in important biological events that are often modulated by specific sequences and sulfation patterns, but their structural analysis remains challenging. Matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) analysis of three different sulfated oligosaccharides (Fondaparinux, the octasulfated pentasaccharide, a disulfated heparin-derived tetrasaccharide 1, and an octasulfated maltoheptaose) 2 was performed using the 2-(4-hydroxyphenylazo)benzoic acid-tetramethylguanidinium (HABA-TMG2) matrix. High resolution mass spectrometry of the main ions observed was successful, and this was complemented by tandem mass spectrometry (MS/MS) analysis for structural assessment. Despite sulfate losses, fully sulfated molecular ions were observed and these allowed the determination of oligosaccharide structures: UA-GlcNAc-UA(2S)-AnhMan(6S) for compound 1 and (Glc6S)6-Glc (1S,6S) for compound 2.

scholarly journals Phytochelatin database: a resource for phytochelatin complexes of nutritional and environmental metals

Database ◽  
2019 ◽  
Vol 2019 ◽  
Author(s):  
Kristine K Dennis ◽  
Karan Uppal ◽  
Ken H Liu ◽  
Chunyu Ma ◽  
Bill Liang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Metal Complexes ◽  
Chain Length ◽  
High Resolution Mass Spectrometry ◽  
R Package ◽  
Large Set ◽  
Mass Spectral ◽  
And Function ◽  
Impact Absorption

Abstract Phytochelatins (PyCs) are a diverse set of plant compounds that chelate metals, protect against metal toxicity and function in metal homeostasis. PyCs are present in plants consumed as food by humans and could, in principle, impact absorption and utilization of essential and toxic metals such as selenium and cadmium, respectively. PyCs vary in terminal amino acid composition and chain length, exist in multiple oxidation states and reversibly bind multiple metals; consequently, PyCs include a large set of possible structures. Although individual PyC-metal complexes have been studied, no resource exists to characterize the diversity of PyCs and PyC-metal complexes. We used the scientific literature to develop a database of elemental formulas for polymer forms varying in chain length from 2 to 11 glutamyl-cysteine repeats. Using elemental formulas, we calculated monoisotopic masses using the most abundant isotopes of each element and calculated masses for complexes with 13 metals of nutritional and toxicological significance. The resulting phytochelatin database (PyCDB) contains 46 260 unique elemental formulas for PyC and PyC-metal complexes. The database is available online for download as well as for direct mass queries for mass spectrometry using an accurate mass annotation tool for user-selected PyC types, metals and adducts of interest. We performed studies of a commonly consumed food—onion—to validate the database and test utility of the tool. Onion samples were analyzed using ultra-high resolution mass spectrometry-based metabolomics. Mass spectral features were annotated using the PyCDB web tool and the R package, xMSannotator; annotated features were further validated by collision-induced dissociation mass spectrometry. The results establish use and a workflow for PyCDB as a resource for characterization of PyCs and PyC-metal complexes.

scholarly journals A combined flow injection/reversed phase chromatography – high resolution mass spectrometry workflow for accurate absolute lipid quantification with 13C- internal standards

The Analyst ◽  
2021 ◽  
Author(s):  
Harald Schoeny ◽  
Evelyn Rampler ◽  
Yasin El Abiead ◽  
Felina Hildebrand ◽  
Olivia Zach ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
Flow Injection ◽  
High Resolution Mass Spectrometry ◽  
Reversed Phase ◽  
Internal Standards ◽  
Lipid Quantification ◽  
High Resolution Mass ◽  
Resolution Mass

We propose a fully automated novel workflow for lipidomics based on flow injection- followed by liquid chromatography high resolution mass spectrometry (FI/LC-HRMS). The workflow combined in-depth characterization of the lipidome...

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