Some biological activity and chemical constituents of the egyptian marjoram and bitter orange volatile oilsAuthor(s): K.S.Khater, Mohamed H.M.Abd El Azim
In this study; chemical constituents of the two oils were analyzed by GC/ MS.About 20 and 32 volatile compounds were identified fromthe volatile oils of O. majorana and C. aurantium respectively. Terpinen-4 Âol and terpinene were the major isolated constituents of O. majorana, while limonene and 2-methyl-5-(1-methyl ethenyle)-2-cyclohexene-1-one were the major compounds of C. aurantium oil. Larvicidal activity ofmarjoram (Origanum majorana), (family: Verbenaceae) and bitter orange (Citrus aurantium), (family: Rutaceae) volatile oils were tested against the early fourth instar larvae of Culex pipiens. The larval mortality was observed after 24 hours of exposure. Both of the two oils showed high larvicidal effects; however, the highest larval mortality was found in the treatment withmarjoramvolatile oil. The LC50 values are 188.5 ppmand 251.4 ppmfor marjoram and bitter orange respectively.