Data TOF and IT

Increased implementation of molecular networking and dereplication in the natural product research in the last years made the expansion of open-access spectra-based databases necessary. The rate of new substance identifications, which lead to a discovery of new natural products with potential pharmacological properties, depends on the quality and extent of used databases.The aim of this master thesis is the establishment of a MS/MS-database in order to increase available data in spectra-based databases. Two natural product classes were selected – sesquiterpenes and triterpenoids. First MS/MS-data for 42 sesquiterpenes and 81 triterpenoids was generated in silico using CFM-ID-Platform. The purity of sesquiterpenes was insufficient for a successful automated mass spectrometry, therefore the MS/MS-spectra were manually produced using direct injection ESI-IT-MS. Nevertheless, the sesquiterpenes were excluded from further work and the focus was placed on triterpenoids.MS/MS-spectra of triterpenoids were obtained using ESI-IT-MS and high-resolution ESI-qTOF-MS. ESI is the most used ionization technique in natural product research and was for this reason applied in this master thesis. IT-MS was performed with and without added buffer in both positive and negative modes. After evaluation of the spectra, it was found that the triterpenoids were better ionizable in the negative mode, which led to qTOF-MS only being performed in the negative mode. For 24 triterpenoids no useful MS/MS spectra were generated by either method, while for 31 triterpenoids fragmentation data were provided by both methods. MGF-Files, containing fragmentation data from the three spectra sources were generated.