Chemotaxonomic Profiling and Bioactive Compound Analysis of Five Euphorbia species Using GC–MS and Phytochemical Screening
Okechukwu, C. L. *
Department of Plant Science and Biotechnology, Abia State University, P.M.B. 2000, Uturu, Nigeria.
Nwaru, C. E.
Department of Plant Science and Biotechnology, Abia State University, P.M.B. 2000, Uturu, Nigeria.
Aku, B. M.
Department of Plant Science and Biotechnology, Abia State University, P.M.B. 2000, Uturu, Nigeria.
Anyanwu, B. C.
Department of Plant Science and Biotechnology, Abia State University, P.M.B. 2000, Uturu, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Background: Chemotaxonomy exploits patterns of secondary metabolite expression to aid taxonomic circumscription and generate hypotheses on evolutionary relationships among plant taxa. The genus Euphorbia (Euphorbiaceae), one of the most species-rich angiosperm genera, is extensively used in ethnomedicine; however, comparative chemical evidence relevant to species delimitation and infrageneric differentiation remains limited. This study examines chemosystematic relationships among five Euphorbia species using integrated phytochemical and multivariate approaches.
Methods: Five species (Euphorbia milli, E. caranensis, E. maculata, E. heterophylla, and E. hirta) were analyzed by gas chromatography–mass spectrometry (GC–MS) to characterize the constituents, complemented by qualitative screening of major secondary metabolite classes. The combined chemical dataset was converted into binary characters and analyzed using hierarchical agglomerative clustering based on the Jaccard similarity coefficient and the UPGMA algorithm to construct a chemophenetic dendrogram.
Results: Ten metabolites were conserved across all examined taxa, with dodecanoic acid and tetradecane interpreted as putative synapomorphic chemical markers indicative of shared ancestry within the genus. Metabolite profiles were dominated by fatty acids, fatty acid methyl esters, hydrocarbons, and phenolic derivatives, reflecting a shared chemophenetic framework. Distinct taxon-specific chemical patterns were evident: E. heterophylla exhibited the highest relative abundance of dodecanoic acid (16.24%), E. milli was characterized by cis-vaccenic acid and long-chain alkenes, and E. caranensis showed elevated dodecanoic acid together with 2,4-di-tert-butylphenol. E. maculata and E. hirta displayed moderate and comparable fatty acid profiles. Cluster topology suggested two principal chemotaxonomic lineages, providing evidence for infrageneric differentiation.
Conclusion: The identification of synapomorphic and diagnostic chemical characters, combined with ethnomedicinally relevant metabolites, supports the utility of chemotaxonomic data in cladistic inference, species delimitation, and infrageneric classification within Euphorbia.
Keywords: Euphorbia species, chemotaxonomy, GC-MS Phytochemical, tetradecane, vaccenic acids