Assessing molecular similarity/diversity of chemical structures by FT-IR spectroscopy

FT-IR spectra have been investigated for their ability to distinguish compo unds which are chemically diverse and to produce clusters of compounds whic h makes sense chemically. Principal component analysis (PCA) was applied to the analysis of a small database of FT-IR spectra. The effect of the data pretreatment step of log transformation on spectral data pattern was also v isualized by using PCA plots. The method of sequential projection pursuit ( SPP) was applied to detect inhomogeneities in the data. Finally, cluster an alysis of these spectra, depending on unweighted pair-group average linkage , was carried out. (C) 2001 Elsevier Science B.V. All rights reserved.