Determination and Profiling of Secondary Metabolites in Aloe vera, Aloe arborescens and Aloe saponaria

Abstract

Metabolomics is as an innovative technique for discriminating plant species. The objective of this study was to investigate the secondary metabolites of three different Aloe species, A. vera, A. arborescens, and A. saponaria profiled by 1 H-NMR analysis. Principal component analysis (PCA) derived from the 1 H-NMR spectra indicated a clear discrimination among the Aloe species, providing high predictability and good fitness of the PCA model (R2 = 0.928 and Q2 = 865). As observed in the PLS-DA score plot, discrimination was observed in the Aloe species with respect to primary metabolites including sugar and organic acid and secondary metabolites such as phenylpropanoids and carotenoids. A. vera was characterized by high levels of malate. On the other hand, as compared to the other Aloe species, A. arborescens was characterized by higher levels of aloenin and sugar metabolites such as sucrose and glucose. Furthermore, the secondary metabolites were quantitatively analyzed by HPLC, and the amounts of carotenoids including zeaxanthin, α- and β-carotene, and phenylpropanoids in A. arborescens were found to be significantly higher than those in the other Aloe species. In conclusion, we demonstrated that 1 H-NMR-based metabolomics with chemometric analysis can be used for the facile discrimination of Aloe species.