CASMI 2013: Identification of Small Molecules by Tandem Mass Spectrometry Combined with Database and Literature Mining

Winners of CASMI2013: Automated Tools and Challenge Data

“…Team Newsome accumulated such product ions of various classes of metabolites on its own in-house mass spectral database. 20) e database supported the team's winning the contest. MS 2 data for Challenges 11 and 12 showed product ions characteristic to curcuminoids and avones, respectively.…”

“…A few days later, team Newsome provided a hypothesis, whereby, in a hydration reaction at the epoxide group of aloxistatin, a glycol derivative of aloxistatin is formed inside the mass spectrometer, and the glycol is the source of the product ion. 20) e CASMI2013 organizers regret this error and express our apologies to all of the other participants that Challenge 13 was, in fact, MS 2 data of a mixture of two di erent small molecules. e lesson we learned is that the quality of the challenge data should be con rmed by manual interpretation of the data as well as by analysis on di erent analytical platforms.…”

“…e solution to Challenge 4 is the smallest molecule, 210 Da; it consists of two phenyl rings and one carbonyl group. Although di erent combinations of two phenyl rings and a carbonyl group within a chemical structure generate many possible chemical structures other than the actual solution, team Newsome manually interpreted the Challenge 4 data, which analyzed the challenge molecule within a mass tolerance of ≤3 ppm, and nally re ned the three chemical structures, which are the solution structure and two highly commended structures (see "Aim of the challenges, and ions leading to the solutions" in the present article and the report by team Newsome 20) ). Automated tools could reduce the number of false-positive candidates by integrating the knowledge of relationships between product ions and chemical substructures, and by integrating the two hydrogen migrations during CID.…”

“…20) (2) e team of Lars Ridder and Justin J. J. van der Hoo , Wageningen University, Wageningen, e Netherlands, and the University of Glasgow, UK, team 'Ridder,' participated in the contest with an automated tool, MAGMa.…”

“…In their proposed scheme, only a mixture of the two diketo-enol tautomers could generate all the observed product ions, because the two tautomers give di erent sets of product ions. e molecular formula and mass of the challenge molecule are C 20 − . 17,18) In the literature, 17) a product ion m/z 171 has been reported to be a characteristic ion of avones with a trihydroxyl group on the A ring, although it is not observed in Challenge 12.…”