Chemical composition, antifungal and in vitro antioxidant properties of Monarda didyma L. essential oil

The chemical composition of the essential oil obtained from Monarda didyma stem with leaves and flowers was analyzed by GC and GC/MS and the components identified were 22, mainly thymol (57.3% and 51.7%, respectively), gamma-terpinene (9.3% and 14.3%), p-cymene (10.5% and 9.7%),delta-3-carene (4.5% and6.2%) and myrcene (3.7% and 3.7%). The two oils were qualitatively similar. The antifungal activity of the oil was evaluated against four phytopathogenic fungi by direct contact with the Agar diffusion method and with the fungistate action of the vapors using the Micro-atmosphere method. The most sensitive fungus resulted Rhizoctonia solani in the first test and Botrytis cinerea in the second. The antioxidant activity of the oil was evaluated by DPPH test, were the oil showed an effect comparable to Trolox, and by lipid peroxidation test, where the activity of the oil was similar to that of BHT.