11 June 2020

NaToxAq chemicals in online databases

In the last decade, many approaches and tools have been developed to improve identification of unknown compounds in environmental samples beyond target analysis [1]. While in target analysis, the compounds of interest are known and standards are available, in suspect and non-target screening analysis they are not necessarily required or even their chemical structure is unknown.

Suspect screening is an analytical tool to screen samples for compounds that could be suspected in the sample, but without having the analytical standards for these compounds. A successful suspect screening builds on smartly created and curated suspect lists containing relevant compounds for a specific research area. Universal chemical databases such as PubChem or ChemSpider are too large to be utilised in a general suspect screening without a priori knowledge from tandem mass spectrometry and other lines of evidence (for example number of publications or patents) to reduce candidate lists retrieved from the large databases. In suspect screening, only the exact mass and the retention time information is used. Both could be derived from the suspected structures and followed by measured or predicted retention times. Mass spectral libraries are the golden standards for the identification of unknown compounds in samples.

Creating smart lists of relevant compounds is part of the daily work of many environmental scientists. Nowadays, this is a big community effort if they are shared in publications and / or uploaded in repositories such as NORMAN Suspect List Exchange . In cases where analytical standards are available, generation of mass spectral library records and upload in a mass spectral library such as MassBank Europe (https://massbank.eu/MassBank) is welcome.

NaToxAq is supporting the NORMAN initiatives. MassBank Europe contains 3756 mass spectra of natural compounds obtained from NaToxAq researchers. A list of 131 compounds was compiled of the MassBank records and uploaded to NORMAN SLE as list S64 NaToXAq. This list is also visible on the US EPA Dashboard, ZENODO and PubChem (for example the mass spectra of Ptaquiloside.

We are grateful to Emma Schymanski (LCSB, Luxemburg), Antony Williams (US EPA) and Evan Bolton (NIH) for their support to make the NaToxAq data available on SLE, US EPA Chemical Dashboard and PubChem.