Major Antifungals in Nutmeg Essential Oil against Aspergillus flavus

Aiming to substitute toxic synthetic fungicides, the activity of nutmeg (Myristica fragrans) essential oil (EO, obtained by hydrodistillation) was investigated against two important storage fungi-Aspergillus flavus A. ochraceus. The activity of crude nutmeg EO was investigated using poison food assay (PFA). At a concentration of 0.1%, the EO inhibited A. flavus and A. ochraceus growth by 43 and 65%, respectively. At a concentration of 0.3 %, A. flavus and A. ochraceus inhibitions were 84 and 79%, respectively. The crude nutmeg EO on fractionation by preparative TLC-bioautography presented one band from which two pure compounds were isolated by semi-preparative normal-phase high performance liquid chromatography. Myristicin and safrole were identified by nuclear magnetic resonance (1H and 13C) and gas chromatography-mass spectrometry. The relative % of myristicin and safrol in the crude EO was 10.8 and 2.9, respectively, determined by gas chromatography with a flame ionization detector. The crude EO, the isolated active fraction, isolated myristicin and standard myristicin presented similar activities against the two fungi at concentrations of 0.1 and 0.3 % by PFA. Based on these results it is concluded that myristicin is the major antifungal in nutmeg EO against A. flavu