Towards an automatic structure elucidation process in various chemical workflows by LC-HRMS and NMR data analysis

254th ACS National Meeting, Washington DC (United States of America) 20 August 2017 


MassChemSite (Molecular Discovery, Ltd. UK) is a novel vendor agnostic software which automatizes the peak finding and structure elucidation from LC-HRMS analytical data obtained from chemical reaction samples, speeding up this task. MassChemSite can identify the reactants and products of a sample based on MS/MSMS information and the chemical reactions under consideration.

Two new features were recently added to MassChemSite: the first one is a method applied to elucidate unknown structures (i.e., when the m/z found is not obtained by the combination of reactions used as input) from unassigned LC-HRMS peaks. First, m/z values from the input MSMS are queried in a database of fragments of compounds (built from user compounds, or previously built and provided). Then, a set of candidate compounds is built by rational combination of the fragments found in the database.

Finally, all the candidates are fragmented and compared with the peaks of the input MSMS spectra. The second feature is an algorithm that uses different NMR acquisition methodologies to discriminate between multiple solutions, for example when LC-HRMS analysis cannot provide a unique structural solution, or to further refine the results of the unknown structure elucidation method. Chemists can load directly to the program a processed NMR experiment file or add the NMR data by hand. The experimental data (1D or 2D experiments) is compared to the predicted one based on the structures proposed by the LC-HRMS analysis, keeping only those solutions where the predicted and experimental NMR data match.