Loranthus tienyenensis Li and Planchonella obovata (R. Br.) Pierre: Essential Oil Composition, Biological Activity, and Molecular Docking.

This study presents the first phytochemical analysis of the essential oils from the fresh leaves of Loranthus tienyenensis Li and Planchonella obovata (R. Br.) Pierre using gas chromatography-mass spectrometry. L. tienyenensis essential oil was characterized by neryl isobutanoate (13.8%), linalool (10.8%), cis-linalool oxide (6.5%), hexadecanoic acid (6.2%), trans-linalool oxide (5.6%), and cis-phytol (5.5%). P. obovata essential oil was dominated by (Z,E)-α-farnesene (13.7%) and (3Z)-cembrene A (12.0%). P. obovata essential oil exhibited strong antimicrobial activity against Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa, and the yeast Candida albicans, with the same minimum inhibitory concentration of 32 µg/mL. Both essential oils showed moderate larvicidal activity against third-instar larvae of Aedes aegypti, Ae. albopictus, and Culex quinquefasciatus, with 24-h lethal dose 50% values below 100 µg/mL. Molecular docking revealed that (Z,E)-α-farnesene interacted with bacterial proteins enoyl-ACP reductase (FabI), dihydrofolate reductase (DHFR), and beta-lactamase, while (3Z)-cembrene A effectively targeted DHFR, DNA gyrase, and peptidoglycan transpeptidase.