Application of Chemometrics and HPLC Fingerprint for Species Differentiation and Authentication of the Genus Pterocarpus

Abstract

Pterocarpus species are well known for their nutritional and medicinal values, in order to examine the similarities or differences in the chemical profile of some common Pterocarpus species, four species of the genus namely; Pterocarpus erinaceus, P. mildbraedii, P. osun and P. santalinoides were analyzed using HPLC combined with Principal component analysis (PCA) and Hierarchical clustering analysis (HCA). This study aims to investigate the chemical fingerprints of the species and compare them in order to highlight the similarities in their chemical constituents. The ethanol extract of each sample was taken and filtered through a 0.45 μm millipore membrane filter and then transferred into the HPLC vial before injecting it into the HPLC machine. PCA and HCA were performed on the relative retention times and percentage peak composition. The species were chemically similar with nine (9) peaks in common, the most prominent peaks in all samples appeared at 3.26 min which corresponds to gallic acid (a known compound). Cluster analysis revealed some similar chemical variables with Gallic acid being the major compound in the Pterocarpus species and could be used as a marker compound for taxonomic purposes.