Antimicrobial and Antioxidant Compounds in the Nonvolatile Fraction of Expressed Orange Essential Oil

Three permethoxylated flavones, dehydroabietic acid and linoleil monoglyceride were isolated from the nonvolatile residue of orange essential oil. All of them exhibited antifungal activity against phytopathogenic species and food contaminants. The isolated hexa- and heptamethoxy flavones exhibited important fungicidal activity against Geotrichum candidum, which is not inhibited by the commercial broadspectrum fungicide Benomyl (methyl-1-[butylcarbamoyl]-2-benzimidazolecarbamate); in addition, these compounds also exhibited effective antioxidant activities, similar to that shown by tert-butyl-4-hydroxyanisol, one of the most commonly used synthetic antioxidants; alpha-tocopherol, the most widely used natural antioxidant, was also isolated.