Hydroxycinnamic Acid Antioxidants: An Electrochemical Overview

Abstract

Hydroxycinnamic acids (such as ferulic, caffeic, sinapic, and p-coumaric acids) are a group of compounds highly abundant in food that may account for about one-third of the phenolic compounds in our diet. Hydroxycinnamic acids have gained an increasing interest in health because they are known to be potent antioxidants. These compounds have been described as chain-breaking antioxidants acting through radical scavenging activity, that is related to their hydrogen or electron donating capacity and to the ability to delocalize/stabilize the resulting phenoxyl radical within their structure. The free radical scavenger ability of antioxidants can be predicted from standard one-electron potentials. Thus, voltammetric methods have often been applied to characterize a diversity of natural and synthetic antioxidants essentially to get an insight into their mechanism and also as an important tool for the rational design of new and potent antioxidants. The structure-property-activity relationships (SPARs) correlations already established for this type of compounds suggest that redox potentials could be considered a good measure of antioxidant activity and an accurate guideline on the drug discovery and development process. Due to its magnitude in the antioxidant field, the electrochemistry of hydroxycinnamic acid-based antioxidants is reviewed highlighting the structure-property-activity relationships (SPARs) obtained so far.

Methanol extracts from Cystoseira tamariscifolia and Cystoseira nodicaulis are able to inhibit cholinesterases and protect a human dopaminergic cell line from hydrogen peroxide-induced cytotoxicity

“…Hydroxycinnamic acids including ferulic, caffeic, sinapic and p-coumaric acids are phenolic compounds widely distributed in plants and also present in algae (Shahidi & Chandrasekara 2010;Novoa et al 2011). These compounds display a strong anti-radical activity, which is related to their capacity to donate hydrogen or electron, and to delocalise/stabilise the resultant phenoxyl radical (Teixeira et al 2013). The highest hydroxycinnamic acids content in C. tamariscifolia could thus explain its higher RSA, when compared with C. nodicaulis.…”

Biologically active phenolic compounds in buckwheat, oats and winter spelt wheat

“…They are generally found esterified or bound to cell wall and only a minor fraction exists as free acids. The antioxidant activity is strongly dependent on phenolic acid structural features and related to the presence of hydroxyl function(s) in the aromatic structure (Teixeira et al, 2013). The avenanthramides, which are characteristic of oats only, are all composed of an anthranilic acid part and a cinnamic acid part, where the substitution pattern on the two parts is what distinguishes the different avenanthramides from each other (Skoglund, 2008;Mackevic, 2010).…”

Ferulic acid in cereals - a review

“…It is informed that approximately 85% of phenolic acids are in the bound form in maize, approximately 75% in wheat and oat, and 62% in rice (Adom & Liu 2002). Cinnamic acids have been categorised as bioactive ingredients of the diet (Kroon & Williamson 1999;Shahidi & Chandrasekara 2010;Teixeria et al 2013).…”