Phenolic acids radical scavenging activity

Fig. 7.3 Radical scavenging activity as measured in the DPPH assay versus (a) total ginsenoside content (% w/w) and (b) total phenolics (pg quercetin per mg extract) of eight ginseng root samples (n = 3). The log IC50 of each sample was divided by the log IC50 of the standard ascorbic acid to...

Silva, E. A. M. Borges, E Gulmaraes, C. Lima,]. L. F. C. Matos, C. Reis, S. Phenolic Acids and Derivatives Studies on the Relationship among Structure, Radical Scavenging Activity, and Physicochemical Parameters.]. Agric. Food Chem. 2000, 48, 2122-2126. 

Citrus sinensis (L.) Osbeck - laranjeira, laranja Tranquilizer Leaf (infusion or decoction, ingested) Caboclos [57,59] Quilombolas [54] Flavonoids [206,207] essential oils [208,209] phenolic compounds Coumarins, fatty acids [210,201] quinoline alkaloids [211,212] Radical scavenging activity [276] antioxidant activity [277] inotropic effect [278]... 

Gruz J, Ayaz FA, Torun H, Strand M (2011) Phenolic acid content and radical scavenging activity of extracts from medlar (Mespilus germanica L.) fruit at different stages of ripening. Food Chem 124 271... 

A rapid fluorometric determination of / -coumaric, protocatechuic, and gallic acids has also been proposed in persimmon [12], but interference with other phenolic compounds is likely. Moreover, the radical scavenging activities of HBA and HCA may be used for their quantitative determination by chemiluminescence in the presence of hydrogen peroxide [13]. 

Cranberries (Vaccinium macrocarpon) are potentially an excellent dietary source of phenolic confounds such as flavonoids, anthocyanins and caffeic acid derivatives which are potent antioxidants. Studies also link a lowered incidence of breast cancer to cranberry juice consumption. In this study, cranberry fruits were fractionated by several methods and tested for radical-scavenging activity in an effort to begin establishing a link between chemical composition and antioxidant activity. The strongest activity was observed in flavonoid-rich extracts. Cytotoxicity assays in several tumor cell lines showed some specificity for HT-29 tumor cells and K562 cells from a methanolic cranberry extract containing several phenolic compounds. 

Free radical scavenging activities of different phenolic acids, caffeic acid (CA), ferulic acid (FA) and p-coumaric acid (p CA) and natural antioxidants alpha tocopherol (alpha-toco) and BHA a synthetic antioxidant were compared with sinapic acid (SA). As indicated in Figure 15.10 under the tested conditions, the radical scavenging activity of the phenolic acids in the DPPH system decreased in the following order ... 

The theoretical contribution of the phenolic constituents, such as free sinapic acid, sinapoyl glucose and sinapine, to the total radical scavenging activity of the extracts is shown in Figure 15.11. The concentration of the phenolic constituents was recorded by HPLC (330 nm). Calibration curves for the RSA were recorded using standard compounds. 

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