LC-Based Metabolomics and Multivariate Analyses Reveal Metabolite Variations in Different Propagation Methods of Eurycoma longifolia Roots Harvested at Different Ages and Locations

Eurycoma longifolia is a well-known medicinal plant with pharmacological effects and important bioactive compounds such as alkaloids and quassinoids. The suitable age of harvesting E. longifolia root for commercial use is relatively unknown and could influence the overall bioactive compounds present in the plant. In this study, non-targeted liquid chromatography mass spectrometer (LC-MS) and multivariate analyses (MVA) were performed to determine the chemical constituent of aqueous extract of 3-month-old E. longifolia hairy root (HR) culture, 1-, 4- and 11-year-old harvested E. longifolia roots. Unsupervised principle component analysis (PCA) and supervised partial least square discriminant analysis (PLSDA) were applied to evaluate metabolic similarities and differences in E. longifolia roots and hairy root in response to different harvesting age, locations and propagation methods. A total of 34 significant buckets with variable importance in projection (VIP) exceeding 1 were selected and identified. It was found that putatively identified quassinoids were significantly higher in 1-, 4- and 11-year-old E. longifolia roots whereas putative canthin-6-one alkaloids were abundantly present in 3-month-old E. longifolia hairy root (HR). These findings may be applicable to improve the harvesting age and increase the content of bioactive compounds in E. longifolia roots.