Department of Silviculture, Faculty of Forestry, Kasetsart University, Bangkok 10900, Thailand.
Program in Biotechnology, Faculty of Science, Maejo University, Chiang Mai 50290, Thailand.
Molecules. 2022 Jan 20;27(3):680. doi: 10.3390/molecules27030680.
oils are widely used for a variety of purposes. This study investigates the terpenoid compositions and antibacterial and antioxidant activities of eucalypt leaf oils extracted from four clones and one × hybrid clone grown in Thailand. According to GC/MS analysis, the oils were mainly composed of 1,8-cineole, -terpinyl acetate, -caryophyllene, and spathulenol, while 1,8-cineole, -terpinyl acetate, -cymene, and -terpinene were mostly identified in the hybrid oil. All eucalypt oils exhibited a significant bacteriostatic effect against Gram-positive bacteria, , , , and . Only the hybrid oil had an effect on all Gram-negative bacteria tested, including , , , and . These oils have antibacterial properties that vary according to their terpenoid content. Only the hybrid oil had a potent antioxidant effect, with an IC value of 4.21 ± 0.35 mg/mL for free radical (DPPH) scavenging. This oil's antioxidant effect may be a result of the phenolic terpenoids, thymol and carvacrol. As a result, these oils may be a novel source of antibacterial and antioxidant agents. Additionally, the antibacterial and antioxidant capabilities of the × hybrid essential oil are reported for the first time.
油类被广泛应用于各种用途。本研究调查了从泰国种植的四个无性系和一个杂交种的桉树叶片油的萜烯成分以及抗菌和抗氧化活性。根据 GC/MS 分析，这些油主要由 1,8-桉树脑、乙酸-松油酯、-石竹烯和蛇麻烯醇组成，而在杂交油中主要鉴定出 1,8-桉树脑、乙酸-松油酯、-柠檬烯和-松油烯。所有桉树油对革兰氏阳性菌、、、和都有显著的抑菌作用。只有杂交油对所有测试的革兰氏阴性菌都有作用，包括、、和。这些油具有根据其萜烯含量而变化的抗菌特性。只有杂交油具有很强的抗氧化作用，其自由基（DPPH）清除的 IC 值为 4.21±0.35mg/mL。这种油的抗氧化作用可能是由于酚类萜烯、百里香酚和香芹酚。因此，这些油可能是新型的抗菌和抗氧化剂来源。此外，还首次报道了杂交种桉叶油的抗菌和抗氧化能力。
