title: Antioxidant activity and characterization of volatile constituents of Taheebo (Tabebuia impetiginosa Martius ex DC).
abstract: Volatiles were isolated from the dried inner bark of Tabebuia impetiginosa using steam distillation under reduced pressure followed by continuous liquid-liquid extraction. The extract was analyzed by gas chromatography and gas chromatography-mass spectrometry. The major volatile constituents of T. impetiginosa were 4-methoxybenzaldehyde (52.84 microg/g), 4-methoxyphenol (38.91 microg/g), 5-allyl-1,2,3-trimethoxybenzene (elemicin; 34.15 microg/g), 1-methoxy-4-(1E)-1-propenylbenzene (trans-anethole; 33.75 microg/g), and 4-methoxybenzyl alcohol (30.29 microg/g). The antioxidant activity of the volatiles was evaluated using two different assays. The extract exhibited a potent inhibitory effect on the formation of conjugated diene hydroperoxides (from methyl linoleate) at a concentration of 1000 microg/mL. The extract also inhibited the oxidation of hexanal for 40 days at a level of 5 microg/mL. The antioxidative activity of T. impetiginosa volatiles was comparable with that of the well-known antioxidants, alpha-tocopherol, and butylated hydroxytoluene.
authors.affiliation: Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Albany, California 94710, USA.
authors.forename: Byeoung-Soo
authors.initials: BS
authors.lastname: Park
authors.forename: Kwang-Geun
authors.initials: KG
authors.lastname: Lee
authors.forename: Takayuki
authors.initials: T
authors.lastname: Shibamoto
authors.forename: Sung-Eun
authors.initials: SE
authors.lastname: Lee
authors.forename: Gary R
authors.initials: GR
authors.lastname: Takeoka
mesh_terms: D000081248:Allylbenzene Derivatives; D000840:Anisoles / Q000032:analysis / Q000494:pharmacology; D000975:Antioxidants / Q000032:analysis* / Q000494:pharmacology*; D001547:Benzaldehydes / Q000032:analysis / Q000494:pharmacology; D002849:Chromatography, Gas; D008401:Gas Chromatography-Mass Spectrometry; D019684:Magnoliopsida / Q000737:chemistry*; D010084:Oxidation-Reduction; D024301:Plant Bark / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry*; D011748:Pyrogallol / Q000031:analogs & derivatives* / Q000032:analysis / Q000494:pharmacology; D014835:Volatilization
chemical_list: D000081248:Allylbenzene Derivatives; D000840:Anisoles; D000975:Antioxidants; D001547:Benzaldehydes; D010936:Plant Extracts; D011748:Pyrogallol; C002135:elemicin; C009760:mequinol; C066943:anisyl alcohol; C006578:anethole