Efficient separation of Cinnamomum camphora leaf essential oil and in vitro evaluation of its antifungal activity

Cinnamomum camphora leaf essential oil (CEO) was extracted using enzymatic -ultrasound pretreatment followed by microwave assisted extraction (EUP-MAE) method and simultaneously studied as a mycelial growth inhibitor against five important pathogens which cause potato dry rot. The optimum EUP-MAE conditions with a real CEO yield of 19.23 +/- 0.12 mg/g were obtained through Plackett-Burman design and Box-Behnken design as follows: 3 % of enzyme dosage, 2 h of pretreatment time, 5 of pH, 210 W of ultrasound power, 50 degrees C pretreatment temperature, 16 mL/g of water to solid ratio, 30 min of microwave time and 500 W of microwave power. Compared to the reference methods, EUP-MAE possessed a highest CEO yield than these of ultrasound-microwave assisted extraction (U-MAE) and traditional hydrodistillation (HD). Gas chromatography-mass spectrometry (GC-MS) analysis demonstrated that eucalyptol, camphor, and a-terpineol were the three main constituents of CEO. Results from in vitro antifungal activity assay revealed that the mycelial growths of all the five tested Fusarium solani, Fusarium culmorum, Fusarium trichothecioides, Fusarium sporotrioides, and Fusarium avenaceum were apparently affected by CEO. These findings not only provide a potential paradigm for the separation of plant essential oil, but also guarantee a promising utilization of the CEO for potato protection to control the Fusarium spp.(c) 2022 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

Cinnamomum camphora leaf essential oil extracted using enzymatic-ultrasound pretreatment followed by microwave assisted extraction showed strong inhibitory effects on the mycelial growth of five important pathogens causing potato dry rot. The optimized extraction conditions resulted in a higher yield of essential oil compared to traditional methods. The main constituents of the essential oil were identified through gas chromatography-mass spectrometry analysis. In vitro antifungal activity assay confirmed the significant impact of the essential oil on the mycelial growth of Fusarium spp.