NMR-based metabolomics for unraveling oleo-gum resin metabolome of rare Commiphora species: insights into taxonomic variation and tree sex differences.

Abstract

Commiphora species, valued for their resinous cell saps rich in terpenoids and other compounds, are known for their therapeutic benefits. This study aimed to be the first NMR-based metabolome profiling of oleo-gum resin derived from endemic rare Commiphora species. Insights into taxonomic variation and tree sex differences were targeted for future correlation with bioactivities-related assays. Oleo-gum resins and cell sap were collected and extracted by methanol from four naturally growing Commiphora species, including C. gileadensis, C. quadricincta, C. kataf female, and C. kataf male. Afterward, NMR acquisition and spectra interpretation were carried out, including various 1D and 2D-techniques. A total of 36 metabolites were identified, including 3 cycloartane derivatives, 12 amino acids and their derivatives, 7 organic acids, 1 phenolic acid, 6 sugars and sugar alcohols, 6 terpenoids, and 1 nitrogenous compound. Multivariate analysis, employing both unsupervised and supervised modeling, facilitated classification of samples and provided a foundation for future authentication and quality control of these taxa. Notably, C. gileadensis cell sap and C. quadricincta oleo-gum resin were metabolically distinct, enriched in terpenoids such as cycloartane 24-en-1,2,3-triol (1) and 1-acetoxycycloartan-24-ene-2,3-diol (2), while trehalose (24) was more abundant in other species. Further, quantitative NMR (qNMR) quantified 9 metabolite markers detected at high levels in Commiphora accessions. In conclusion, terpenoids were found to be abundant and discriminant compounds in Commiphora products. The results shall aid in the future standardization of Commiphora oleo-gum resins to be included in nutraceuticals and for future correlation with bioactivities-related assays.