Chemical Composition, Anti‐Microbial, and Cytotoxic Activities of Essential Oils from <i>Blumea densiflora</i> var. <i>hookeri</i> (C.B. Clarke ex Hook.f.) C.C. Chang &amp; Y.Q. Tseng Leaves from Vietnam

The essential oil from the leaves of Blumea densiflora var. hookeri was analyzed using GC-MS, and bioassays were performed. GC-MS identified thirty-four constituents, representing 79.1 % of the oil composition. The major compounds identified in the oil were (E)-caryophyllene (15.3 %), viridiflorol (5.5 %), trans-dauca-4(11),7-diene (4.6 %), spathulenol (4.4 %), and isolongifolan-7-α-ol (4.3 %). The antimicrobial activity of the oil was assessed to determine its efficacy against six bacterial strains and one fungal strain using minimum inhibitory concentration (MIC) methods. The essential oil demonstrated antimicrobial activity against all tested microorganisms. A cytotoxicity assay was performed on KB and A549 cancer cell lines using the MTT method. The essential oil displayed strong cytotoxic effects on both cell lines, with IC₅₀ values of 1.40±0.05 μg/mL for KB and 1.72±0.04 μg/mL for A549.