Submitted to: Journal of the Science of Food and Agriculture
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/22/2004
Publication Date: 3/7/2005
Citation: Lee, K.-G., Lee, S.-E., Takeoka, G.R., Kim, J.-H., Park, B.-S. 2005. Antioxidant activity and characterization of volatile constituents of beechwood creosote. Journal of the Science of Food and Agriculture. Vol. 85. p. 1580-1586. Interpretive Summary: In living systems, dietary antioxidants such as a-tocopherol, ascorbic acid, carotenoids, flavonoids and other phenolics, may be effective in protection from oxidative damage. A number of synthetic antioxidants such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), tertiary-butylhydroquinone (TBHQ) and propyl gallate (PG) have been developed, but their use has begun to be restricted to potential health hazards including possible carcinogenicity. As a result, there is considerable interest in the food industry and in preventative medicine in the development of natural antioxidants from botanical sources. These natural constituents possess the ability to reduce oxidative damage associated with diseases such as cancer, cardiovascular disease, cataracts, diabetes, arthritis, immune diseases, aging and brain dysfunction. In our continuing search for interesting biological activity in natural products we investigated the antioxidant activity of beechwood creosote, a colorless to yellowish oily liquid obtained from the distillation of beechwood tar. The material is used in humans as an antiseptic, expectorant, and antidiarrheal agent and in veterinary use as a parasiticide, deodorant and gastric sedative. Beechwood creosote volatiles were identified and the antioxidant activity of the material was tested using three assays. The antioxidant activity of creosote was comparable to that of the well-known antioxidants, a-tocopherol and BHT in the hexanal assay.
Technical Abstract: Volatile constituents of beechwood creosote were determined using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The major volatile constituents of creosote were 2-methoxyphenol (guaiacol; 25.164%), 2-methoxy-4-methylphenol (4-methylguaiacol; 21.437%), 3-methylphenol (m-cresol; 8.273%), 4-methylphenol (p-cresol; 7.888%), 2-methylphenol (o-cresol; 4.578%) and phenol (2.790%). The antioxidant activity of creosote was evaluated by three different chemical assays. Beechwood creosote exhibited potent inhibitory effects on the formation of conjugated diene hydroperoxides (from methyl linoleate) at concentrations of 500, 750 and 1000 mg/mL. Creosote had a potent inhibitory effect on the oxidation of hexanal for 40 days at a level of 5 mg/mL and also inhibited malonaldehyde (MA) formation from ethyl arachidonate by 92 % at a level of 50 mg/mL. The antioxidative activity of creosote was comparable to that of the well-known antioxidants, a-tocopherol and BHT in the hexanal assay. However, creosote displayed comparatively lower antioxidant activity in the other two assays.