Antioxidant activity of phytosteryl phenolates

Abstract

Phytosteryl phenolates occur naturally in many cereals and were successfully synthesized through a twostep chemoenzymatic process, as previously reported. They were also found to exhibit a system dependent antioxidant activity. Three model systems were employed in this study to shed light on the antioxidant activity and action mechanisms involved. The maintaining or enhancing of the antiradical capacity of phytosteryl phenolates in the DPPH assay suggested that these derivatives might be used as antioxidants in more lipophilic systems. However, reducing power of phytosteryl phenolates was lower than that of their phenolic acid counterparts, possibly due to their poor solubility in the aqueous test medium or via micelle formation. In the DNA scission test, phytosteryl phenolates showed either the same/or lower DNA retention ability against both peroxyl and hydroxyl radicals with the exception of phytosteryl caffeates and sinapates, which showed enhanced DNA retention ability against hydroxyl radical. Phytosteryl caffeates also displayed higher activity in DNA retention against peroxyl radical. The antioxidant activity of phytosteryl phenolates was similar or superior to that of their parent phenolic acid counterparts, suggesting their potential use as phenolic acid alternatives with added benefits of phytosterols in the food industry.

Solid‐State Bioprocessing with Cordyceps militaris Enhanced Antioxidant Activity and DNA Damage Protection of Red Beans (Phaseolus angularis)

“…4). Previous researchers stated that phenolic compounds in the samples were effective in inhibiting DNA strand scission (Singh et al 2010;Tan and Shahidi 2014;Xiao et al 2014). Also, the results showed that various extracts of NFRB and CFRB showed significant (P < 0.05) differences in their DNA damage protective effect ( Figs.…”

“…In the hydroxyl radical-induced DNA damage assay, the control plasmid pUC18 DNA was mainly composed of the supercoiled form (approximately 77.23%) in the absence of Fenton's reagent (lane 1 of Figure 3, control). Previous researchers stated that phenolic compounds in the samples were effective in inhibiting DNA strand scission (Singh et al 2010;Tan and Shahidi 2014;Xiao et al 2014). The addition of various extracts of NFRB and CFRB to pUC18 plasmid DNA and Fenton's reagent mixture provided protection to plasmid DNA, resulting in the retention of the native form (supercoiled form, lanes 3-10 of Fig.…”

Enhanced total phenolic and isoflavone aglycone content, antioxidant activity and DNA damage protection of soybeans processed by solid state fermentation with Rhizopus oligosporus RT-3

“…Hydroxyl radical generated by the Fenton reaction are known to cause DNA damage and yield fragmented forms. 18,29,55 The treatment of pUC18 plasmid DNA with Fenton's reagent directed the alteration of supercoiled DNA (native form) to open circular form and linear form (oxidative damaged DNA). In this study, the change of DNA conformation was evaluated by electrophoresis (Fig.…”

Enzymatic synthesis of steryl hydroxycinnamates and their antioxidant activity

“…The activity for free ferulic acid was also found to be higher than the radical scavenging activity of the alkyl ferulates. In an earlier study comparing the DPPH radical scavenging activity of the free acids and their sterol ester in ethanol, a higher activity was found for steryl caffeate, but a lower activity for steryl sinapate compared to the corresponding free acid . To conclude, the type of solvent influences the DPPH radical scavenging activity for esterified and free hydroxycinnamic acids.…”