Differentiation of Mikania glomerata and Mikania laevigata Species Through Mid-infrared Spectroscopy and Chemometrics Guided by HPLC-DAD Analyses

Mikania glomerata Spreng. and M. laevigata Sch. Bip. ex Baker are medicinal plant species from the Asteraceae family popularly known as “guaco” in Brazil. The present study aimed to develop and validate a mid-infrared chemometric model guided by HPLC-DAD for the classification of these two species. Quantitation of chlorogenic acid and coumarin served to guide the classification of the samples. The MIR spectra were analysed by principal component analysis and by partial least squares-discriminant analysis chemometric methods. Samples from other species were also used to challenge the predictive ability of the partial least squares-discriminant analysis. The principal component analysis model was able to discriminate the samples of the three classes (M. glomerata, M. laevigata, and other species). The partial least squares-discriminant analysis model also classified the samples into the three classes, with specificity and sensitivity close to 100%. The developed chemometric model represents a simple and efficient method for the differentiation of guaco species, and it could be used as a tool to authenticate these species.