Chemistry Department, Federal University of Lavras (UFLA), Lavras, MG, Brazil.
Phytopathology Department, Federal University of Lavras (UFLA), Lavras, MG, Brazil.
Lett Appl Microbiol. 2022 Oct;75(4):1028-1041. doi: 10.1111/lam.13782. Epub 2022 Jul 8.
Coffee (Coffea L.) is one of the main crops produced globally. Its contamination by the fungus Hemileia vastatrix Berkeley and Broome has been economically detrimental for producers. The objective of this work was to extract and characterize the essential oils from Eucalyptus citriodora Hook, Eucalyptus camaldulensis Dehn and Eucalyptus grandis Hill ex Maiden, produce and characterize nanoparticles containing these essential oils and evaluate the in vivo and in vitro antifungal activity of free and nanoencapsulated essential oils. The principal constituent of the essential oil from E. citriodora was citronellal; that from E. grandis was α-pinene; and that from E. camaldulensis was 1,8-cineol. The in vitro antifungal activity against the fungus H. vastatrix was 100% at a concentration of 1000 μl l for all the oils and nanoparticles containing these natural products. The sizes of the nanoparticles produced with the essential oils from E. citriodora, E. camaldulensis and E. grandis were 402·13 nm, 275·33 nm and 328·5 nm, respectively, with surface charges of -11·8 mV, -9·24 mV and - 6·76 mV, respectively. Fourier transform infrared analyses proved that the encapsulation of essential oils occurred in the polymeric matrix of poly(ε-caprolactone). The incorporation of essential oils into biodegradable poly(ε-caprolactone) nanoparticles increased their efficiency as biofungicides in the fight against coffee rust, decreasing the severity of the disease by up to 90·75% after treatment with the nanoparticles containing the essential oil from E. grandis.
咖啡（Coffea L.）是全球主要种植的作物之一。其被真菌咖啡驼孢锈菌（Hemileia vastatrix Berkeley and Broome）污染对生产者造成了经济损失。本工作旨在从柠檬桉（Eucalyptus citriodora Hook）、赤桉（Eucalyptus camaldulensis Dehn）和蓝桉（Eucalyptus grandis Hill ex Maiden）中提取并表征其精油，制备并表征含这些精油的纳米粒子，并评估游离精油和纳米封装精油的体内和体外抗真菌活性。柠檬桉精油的主要成分为香茅醇；蓝桉精油的主要成分为α-蒎烯；赤桉精油的主要成分为 1,8-桉叶素。所有含这些天然产物的精油和纳米粒子在 1000μl·L-1浓度下对咖啡驼孢锈菌的体外抗真菌活性均为 100%。柠檬桉、赤桉和蓝桉精油所产生的纳米粒子的粒径分别为 402.13nm、275.33nm 和 328.5nm，表面电荷分别为-11.8mV、-9.24mV 和-6.76mV。傅里叶变换红外分析证明，精油的包封发生在聚（ε-己内酯）的聚合物基质中。将精油掺入可生物降解的聚（ε-己内酯）纳米粒子中，提高了其作为生物杀菌剂防治咖啡锈病的效率，用含蓝桉精油的纳米粒子处理后，病害严重度降低了 90.75%。
