Assessment of volatile compounds variability among two <i>Commiphora</i> species using gas chromatography coupled with chemometric analysis and their biological activities

<i>Commiphora wightii</i> is an important medicinal plant often widely used in ayurvedic medicines. However, the chemical constituents of the essential oil (EOs) obtained from <i>C. agallocha</i> were not well explored. Therefore, the present study aims to get an extreme understanding of the comparative volatile composition of different accessions of two important <i>Commiphora</i> species, namely <i>C. wightii</i> and <i>C. agallocha</i>, using gas chromatography-mass spectrometry (GC-MS), followed by multivariate principal component analysis and partial least squares discriminant analysis-based chemometric analysis. A total of 129 diverse volatile organic compounds (VOCs) were identified in EOs of both <i>Commiphora</i> species, and the concentration of VOCs varied significantly from species to species as well as from accession to accession. In <i>C. wightii</i> EO, 80 compounds were identified, containing sesquiterpenes followed by diterpenes, whereas 49 compounds were identified in <i>C. agallocha</i> EO with high sesquiterpene levels. The GC-MS and chemometric analyses distinguished <i>C. wightii</i> and <i>C. agallocha</i> species based on their qualitative and quantitative variations in terpenoid contents. Both EOs exhibited promising antioxidant activity to the positive standard butylated hydroxyl toluene. The EOs of the <i>Commiphora</i> species exhibited antimicrobial activities in disc diffusion and biofilm assays against two bacterial and one fungal strain; however, <i>C. wightii</i> EO displayed a strong inhibitory effect against <i>Klebsiella pneumoniae, Pseudomonas aeruginosa</i> and <i>Candida albicans</i> compared to other EOs. In this study, we first reported the comprehensive profiling of terpenoid content of <i>C. wightii</i> and <i>C. agallocha</i> stems along with their antibiofilm activity against two pathogenic bacterial strains and one fungal strain in a comparative manner. Based on the comparative antimicrobial assay between two <i>Commiphora</i> species, the EO of <i>C. wightii</i> showed good biofilm inhibition potential against <i>Klebsiella pneumoniae, Pseudomonas aeruginosa</i> and <i>Candida albicans</i> compared with EO of <i>C. agallocha</i>. Based on the current results, the two <i>Commiphora</i> species may be promising ingredients for applications in the pharmaceutical industry.