The identification of individual phenolic acids in phenolic-rich extract prepared by phenolic extraction as described above was carried out using a Waters HPLC system, based on matching spectrum and retention times of phenolic acid standards.
Compound identification was based on mass spectra matching in the standard NIST library and retention time of authentic reference standards.
Identifications were based on mass spectra matching in the standard NIST05 library and retention indices of reference standards in the authors' laboratories.
These MSAlign files were then subsequently searched with the E. coli BL21 database generated from NCBI (accession: PRJEA161949, containing 4192 protein sequences) with the alignment-based MS-Align+ algorithm for protein identifications based on protein-spectrum matches.
Signals in the MALDI tissue imaging data set were identified based on matching fragmentation spectra of lipids extracted from the tissue and prepared lipid standard solutions.
Compound identification was based on matching experimental spectra with references available from Wiley library (version 2005, Wiley, New York, USA).
Database searching is the most common approach and it is based on matching the observed spectrum to theoretical spectra generated from a protein sequence database.
This approach is based on event matching between two traces.
Constraint set simplification is essentially based on instance matching.
The linkage was based on probability matching.
