The effect of extraction methods on the yields, chemical composition and antifungal activity of sawdust Cedrus atlantica Manetti essential oils

The aim of this work is to determine the effect of the extraction method on the yield, the chemical composition, and the antifungal activity of cedarwood essential oils (EOs) from sawdust of Moroccan Cedrus atlantica (C. atlantica). EOs were extracted by different methods: hydrodistillation, soxhlet, maceration, and ultrasound. The chemical composition was determined using gas chromatography mass spectrometry (GC-MS) analysis. The yields of EOs were 5.60%, 11.68%, 4.82% and 9.33% for hydrodistillation, soxhlet, maceration and ultrasound, respectively. GC-MS revealed a diversity of chemical compounds depending on extraction methods. Indeed, the main compound of EOs obtained by soxhlet, maceration, and ultrasound was copalic acid methyl ester by a rate of 28.41%, 20.24%, and 24.17%, respectively. However, -himachalene (21.32%) followed by -himachalene (9.40%), β-Copaen-4α-ol (7.71%) and longifolene (6.74%) are the main compounds of EO extracted by hydrodistillation. The antifungal activity of cedarwood EO was tested in vitro on two pathogenic fungi: Fusarium culmorum (F. Culmorum) and Botrytis cineria (B. Cinerea). The minimum inhibitory concentration (MIC) was determined by successive dilutions of the stock solutions. The extracted EOs by soxhlet, maceration and ultrasound showed the important inhibitory effect against B. cinerea (MIC=1.25 mL/L). However, F. culmorum showed resistance towards all tested EOs. The finding of this study showed clearly that the volatile composition of EOs can be variable according to extraction. methods. Moreover, antifungal effects are depending on chemical composition of EOs but also to tested staris.