Chemical composition and cytotoxicity of the essential oil of Calophyllum fraseri M.R.Hend. & Wyatt-Sm

This study investigates the chemical composition and cytotoxicity potential of Calophyllum fraseri M.R.Hend. & Wyatt-Sm essential oil, complemented by molecular docking analysis. Gas chromatography-flame ionisation detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS) identified 15 components, representing 93.1% of the total oil content. The major components were β-caryophyllene (19.4%), α-cubebene (18.3%), δ-cadinene (14.0%), α-humulene (10.3%), and γ-muurolene (9.5%). The essential oil exhibited weak cytotoxic activity against HepG2, MCF-7, and A549 cancer cell lines, with IC₅₀ values of 93.4 ± 0.15 μg/mL (HepG2), 89.2 ± 0.11 μg/mL (MCF-7), and 96.3 ± 0.12 μg/mL (A549). Molecular docking results revealed favourable interactions between γ-muurolene and Akt1, α-humulene and oestrogen receptor α (ERα), and α-cubebene and the epidermal growth factor receptor tyrosine kinase (EGFR-TK) domain. These docking results provide supportive molecular insights into potential target interactions of individual constituents rather than direct predictors of the biological activity of the crude essential oil.