Anthocyanin characterization and bioactivity assessment of a dark blue grained wheat (Triticum aestivum L. cv. Hedong Wumai) extract

Defatted bran of dark blue grained wheat (Triticum aestivum L., cv. Hedong Wumai) was extracted using ethanol and chemically characterized by HPLC and ESI-MS. Cyanidin-3-glucoside was the predominant anthocyanin in the pigmented wheat which also contained cyanidin-3-galactoside, pelargornidin-3-glucoside, and peonidin-3-glucoside. Ferulic acid was identified as the major simple phenolic acid, with lesser amounts of p-hydroxybenzoic acid, caffeic acid, syringic acid and p-coumaric acid also present. Anthocyanins were separated from phenolic acids using solid phase extraction, and respective fractions were determined for DPPH radical, ABTS radical scavenging tests as well as oxygen radical absorption assay. Results showed that 69% of the overall free radical scavenging capacity of dark blue grained wheat was attributed to the anthocyanin content, compared to 19% for the extractable phenolic acids. In cell based models, the pigmented wheat extract significantly suppressed both hydrogen peroxide-induced intracellular oxidation (p < 0.01) and bacterial lipopolysaccharide-induced nitric oxide (p < 0.05) production. These data report for the first time the major phytochemical composition of pigmented grained wheat and associated bioactivity towards free radical scavenging and suppression of ROS and RNS activity.