Mass spectrometry entropy similarity calculation method for retrieving small molecule compounds

Two kinds of data alignment methods and an information entropy-based mass spectral entropy similarity calculation method are proposed to identify unknown small molecule compounds from known compounds in this paper. The two alignment methods are utilized to convert unequal-length unknown and known mass spectra into equal-length ones to facilitate similarity calculation. The information entropy is used to quantify the difference in intensity distribution in the aligned mass spectra, and the similarity of the aligned mass spectra is compared based on the difference in mass spectral entropy. Example validation results show that the two mass spectral data alignment methods can solve the problem of the unequal length of mass spectral data in the similarity calculation, the mass spectral entropy similarity calculation method is easy to calculate, the results are more reliable, and it is suitable for the search of small molecule compounds with similarity.