Inhibitors of 15-lipoxygenase from orange peel
| Autor: | Karl Egil Malterud, Kjersti M. Rydland |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
chemistry.chemical_classification
Flavonoids Citrus Chemistry Stereochemistry Flavonoid General Chemistry Orange (colour) Free Radical Scavengers Nobiletin Ferulic acid chemistry.chemical_compound Hesperidin Structure-Activity Relationship Arachidonate 15-Lipoxygenase Quercetin Lipoxygenase Inhibitors Sinensetin General Agricultural and Biological Sciences Citrus × sinensis Nuclear chemistry |
| Zdroj: | Journal of agricultural and food chemistry. 48(11) |
| ISSN: | 0021-8561 |
| Popis: | A series of polymethoxylated flavonoids has been isolated from orange peel, and their inhibitory activity toward soybean 15-lipoxygenase was determined. The strongest inhibition was shown by 3,5,6,7,3',4'-hexamethoxyflavone (IC(50) = 49 +/- 5 microM). Sinensetin, nobiletin, tangeretin, tetramethylscutellarein, and 3,5, 6,7,8,3',4'-heptamethoxyflavone were somewhat less active, with IC(50) values of 70-86 microM, comparable to the positive control quercetin (IC(50) = 68 +/- 5 microM). Demethylation apparently results in less active compounds, with 5-O-demethylsinensetin having an IC(50) value of 144 +/- 10 microM. Some other orange peel constituents were isolated and tested as well, hesperidin (IC(50) = 180 +/- 10 microM) and ferulic acid (111 +/- 2 microM), showing moderate activity. The polymethoxylated flavonoids were virtually inactive as scavengers of the diphenylpicrylhydrazyl radical. Hesperidin was only slightly active (24.2 +/- 0.7% scavenged at a concentration of 2 mM), and ferulic acid showed good activity (IC(50) = 86.4 +/- 0.7 microM). From this, it appears that orange peel constituents may counteract enzymatic lipid peroxidation processes catalyzed by 15-lipoxygenase in vitro. The radical scavenging activity of orange peel extracts is only modest. |
| Databáze: | OpenAIRE |
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