Characterization of Phenolic Compounds and Antioxidant Activity of Solanum scabrum and Solanum burbankii Berries

The purpose of this research was to quantify and characterize phenolic compounds and to measure the antioxidant activity of Solanum scabrum and Solanum burbankii berries. The antioxidant activity of Solanum berry extracts was assayed by electrochemical and spectrophotometric methods, whereas liquid chromatography (LC)/quadrupole time-of-flight mass spectrometry and ultra-performance LC-photodiode detector were used for identification and quantification of their polyphenols. Eighteen phenolic compounds were identified in these fruits. The presence of seven phenolic acid derivatives and two flavonols was reported for the first time. In both cultivars, the major compound was found to be anthocyanin petunidin-3-(p-coumaroyl-rutinoside)-5-O-glucoside. Additional anthocyanins in S. burbankii and S. scrabum berries were characterized as petunidin, delphinidin, and malvidin with the same glycosidic substitution pattern and acylation with p-coumaric and ferulic acids. S. scabrum was richer in phenolic compounds, especially anthocyanins, and was characterized by more powerful antioxidant activity than S. burbankii.