Abstract

Citrus Nobilis, belonging to the family Rutaceae, includes about 17 species worldwide, with citrus fruits such as oranges, tangerines, lemons, grapefruits, and citrons being of great agricultural importance. In Vietnam, about 20 citrus species are widely grown, including Citrus nobilis, which is valued for its flavor, nutritional content, and health benefits. Although often considered an agricultural by-product, the peel of Citrus Nobilis contains bioactive compounds, including essential oils, flavonoids, and polyphenols, with reported antibacterial, antifungal, antioxidant, and anti-inflammatory activities. However, the chemical composition and biological properties of Citrus Nobilis collected in Dak Lak, Vietnam, have not been investigated. Gas chromatography- mass spectrometry (GC-MS) was used to identify the chemical composition of Citrus Nobilis essential oil. The 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay and the agar disc diffusion method were used to evaluate the antioxidant and antibacterial activities of the essential oil, respectively. The results of determining the chemical composition of Citrus Nobilis in Dak Lak province showed that contained 12 natural compounds, indicating considerable chemical diversity. The major constituents were D-Limonene (91.96%), 2-β-pinene (2.11%), cis-limonene oxide (1.85%), Carveol (0.85%), α-Terpinene (0.75%), p-Mentha-1(7), 8(10)-dien-9-ol (0.63%), α-Thujene (0.58%). These distinctive features provide an important basis for evaluating the bioactive potential and pharmacological applications of Citrus Nobilis essential oil from Dak Lak.