251. Identification of antiplasmodial triterpenes from Keetia species using NMR-based metabolic profiling
- Author
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Joanne Bero, Denise Medeiros Selegato, Joëlle Quetin-Leclercq, Young Hae Choi, Rafael Teixeira Freire, Claire Beaufay, Aline Coqueiro, and UCL - SSS/LDRI - Louvain Drug Research Institute
- Subjects
Magnetic Resonance Spectroscopy ,Endocrinology, Diabetes and Metabolism ,Metabolite ,Clinical Biochemistry ,Rubiaceae ,01 natural sciences ,Biochemistry ,Terpene ,03 medical and health sciences ,chemistry.chemical_compound ,Antimalarials ,Metabolomics ,Triterpene ,Metabolome ,Keetia venosa ,STOCSY ,030304 developmental biology ,chemistry.chemical_classification ,0303 health sciences ,In vitro antiplasmodial activity ,OPLS ,Chemistry ,Plant Extracts ,010401 analytical chemistry ,Magnetic Resonance Imaging ,Triterpenes ,0104 chemical sciences ,Plant Leaves ,Multivariate Analysis ,Proton NMR ,NMR-based metabolomics ,Original Article ,Two-dimensional nuclear magnetic resonance spectroscopy ,Keetia leucantha - Abstract
Introduction The increase in multidrug resistance and lack of efficacy in malaria therapy has propelled the urgent discovery of new antiplasmodial drugs, reviving the screening of secondary metabolites from traditional medicine. In plant metabolomics, NMR-based strategies are considered a golden method providing both a holistic view of the chemical profiles and a correlation between the metabolome and bioactivity, becoming a corner stone of drug development from natural products. Objective Create a multivariate model to identify antiplasmodial metabolites from 1H NMR data of two African medicinal plants, Keetia leucantha and K. venosa. Methods The extracts of twigs and leaves of Keetia species were measured by 1H NMR and the spectra were submitted to orthogonal partial least squares (OPLS) for antiplasmodial correlation. Results Unsupervised 1H NMR analysis showed that the effect of tissues was higher than species and that triterpenoids signals were more associated to Keetia twigs than leaves. OPLS–DA based on Keetia species correlated triterpene signals to K. leucantha, exhibiting a higher concentration of triterpenoids and phenylpropanoid-conjugated triterpenes than K. venosa. In vitro antiplasmodial correlation by OPLS, validated for all Keetia samples, revealed that phenylpropanoid-conjugated triterpenes were highly correlated to the bioactivity, while the acyclic squalene was found as the major metabolite in low bioactivity samples. Conclusion NMR-based metabolomics combined with supervised multivariate data analysis is a powerful strategy for the identification of bioactive metabolites in plant extracts. Moreover, combination of statistical total correlation spectroscopy with 2D NMR allowed a detailed analysis of different triterpenes, overcoming the challenge posed by their structure similarity and coalescence in the aliphatic region. Electronic supplementary material The online version of this article (10.1007/s11306-019-1487-4) contains supplementary material, which is available to authorized users.
- Published
- 2018