ac500667h_si_001.zip (150.85 MB)
Ultrafast PubChem Searching Combined with Improved Filtering Rules for Elemental Composition Analysis
dataset
posted on 2014-06-03, 00:00 authored by Arjen LommenA new
and improved software tool for elemental composition annotation
of molecular ions detected in mass spectrometry, based on improved
filtering rules followed by ultrafast querying in publicly available
compound databases, is provided. Pubchem is used as a general source
of 1.3 million unique chemical formulas. A plant metabolomics database
containing ca. 100 000 formulas is used as a source of naturally
occurring compounds. Four modes with different sets of rules for heuristic
filtering of candidate formulas coming from elemental composition
analysis are incorporated and tested on both databases. The elemental
composition analysis is then coupled to ultrafast PubChem searching
based on a mass-indexed intermediate system. The performance of the
filters is compared and discussed. When reactive compounds are assumed
not to be present, 99.95% of the 1.3 million PubChem formulas is correctly
found, while ca. 30% less formulas per mass are given compared to
previously published rules. For the ca. 100 000 plant metabolomics
based formulas, 100% fit the improved rules.