Antifungal activity and chemical composition of essential oil of origanum hypericifolium

Abstract

Endemic oregano's, Origanum hypericifolium O. Schwartz and P.H. Davis, essential oil was extracted to exert its biological activity in vitro. Fifteen components in its extracts performed by hydro distillation. The major components in the fruit and flower volatiles of O. hypericifolium were p-cymene (34.33 g/100 g oil), carvacrol (21.76 g/100 g oil), thymol (19.54 g/100 g) and -terpinene (13.91 g/100 g oil). The antifungal activity of O. hypericifoliums oil was evaluated against 14 fungi isolated from hazelnut and walnut. Nuts are capable of harboring toxigenic fungi and the threat of mycotoxin contamination on them exists. Essential oil of O. hypericifolium was found to be active both in contact and headspace assays in vitro producing hyphal growth inhibition. In the contact assay, P. frequentans was found to be the least sensitive species. The more sensitive species were P. castellonense, P. verrucosum. var. cyclopium, C. globosum, and A. kiliense. Their growth was completely (100%) inhibited at days 3 and 6. In the volatile assay, all the mycelial growth of all tested fungi was completely inhibited at day 3. The volatile activity was found to be highly efficient than that of contact activity assay. This could be because of the aromatic contents of Origanum, such as monoterpenes, carvacrol, thymol, and p-cymene. © 2012 Copyright Taylor and Francis Group, LLC.