Classification of llex species based on metabolomic fingerprinting using nuclear magnetic resonance and multivariate data analysis

The metabolomic analysis of 11 flex species, L argentina, L brasiliensis, L. brevicuspis, L dumosa var. dumosa, L dumosa var. guaranina, L. integerrima, L. microdonta, L. paraguadensis var. paraguadensis, L pseudobuxus, L taubertiana, and L theezans, was carried out by NMR spectroscopy and multivariate data analysis. The analysis using principal component analysis and classification of the H-1 NMR spectra showed a clear discrimination of those samples based on the metabolites present in the organic and aqueous fractions. The major metabolites that contribute to the discrimination are arbutin, caffeine, phenylpropanoids, and theobromine. Among those metabolites, arbutin, which has not been reported yet as a constituent of flex species, was found to be a biomarker for L. argentina, L brasiliensis, L brevicuspis, L integerrima, L microdonta, L pseudobuxus, L taubertiana, and L. theezans. This reliable method based on the determination of a large number of metabolites makes the chemotaxonomical analysis of flex species possible.