In our approach, data consistency is checked for the analytical data from 1 H NMR, C NMR spectroscopy and mass spectrometry completely automatically. The analytical interpretation (analysis) given by the data creator is compared with the information from automatically processed molecular structures by cheminformatics tools (cheminformatics toolkits used in this work are described in the SI). For 1 H NMR and C NMR data, the signal interpretation (analysis), either extracted from data files or added manually by the scientists, is parsed to determine the total number of atoms that are referenced and the number is then compared with the molecular formula of the proposed structure (option 2, Figure ). Regarding mass spectrometry data, the data file of the mass spectrum is checked for consistency with the expected values calculated for a specific target structure. Those procedures based on data file approval require some effort as the data may consist of diverse scans belonging to the same measurement. In the process proposed here, we established a protocol to search in all scans of one measurement for the exact mass-to-charge ratio and alternatively for the exact mass +1, +23, and +39, due to proton, sodium, and potassium adduct formation. As an additional method of ensuring consistency, the list of identified mass peaks given in the analytical information is checked for values that correspond to the exact mass of the target molecule or possible combinations thereof (option 3, Figure ). Here again, the verification process also includes the comparison with values that correspond to the exact mass of the target molecule or combinations with the most common species derived from the molecules' exact mass (see supporting information for details) (option 4, Figure ). Level 2 includes the evaluation of data files and analyses for consistency and plausibility with calculations and simulations resulting from the chemical structure. Green squares = evaluation is part of this work, white square = evaluation is not included. Numbers 1-5 refer to the options described in the main text. measurements are processed via the software ChemSpectra 51 and analysed using the QuickCheck service from nmrshiftdb2 (option 1, Figure ) . The process differs for 1 H NMR data and C NMR data as preparation of 1 H NMR data as well as its analysis is more complex than the preparation and analysis of C NMR data. In our model, H NMR spectra to be curated must be manually annotated with regards to multiplicity assignment, and signals not belonging to the expected molecule (such as solvents and impurities) have to be removed. For C NMR data, a process has been implemented, which allows for the automatic selection of signals from a given NMR data file (for a detailed description of the process and its limitations, see supporting information Chapter 2). The shifts of all manually and automatically selected signals from H NMR and C NMR data are then compared to the shifts that can be predicted for the expected molecule by the service from nmrshiftdb2. Depending on the difference between the experimentally found and the simulated shift, a status of "accept", "warning" or "reject" is assigned to each shift (Figure ). The evaluation routine enables the manual correction of those results as the simulated data may contain errors or might not be as precise as necessary for the included tolerances.