Antioxidant and quinone reductase inducing activities of ethanolic fractions from purple maize

Ethanolic extracts of three different varieties of purple maize (Zea mays L.) were examined for scavenging activities toward nitric oxide (NO) and superoxide (·O2−) and the ability to induce quinone reductase (QR). The crude extracts showed a dose-dependent antioxidant activity in the following order: generic purple > Oaxaca 332 > Veracruz 42. The extract of the generic purple variety exhibited the highest ability to induce QR activity and antioxidant activity was split into several fractions that showed antioxidant activities and capacity for doubling QR specific activity. Fraction III doubled QR at a content of 105 μg/mL (CD value). Semi-preparative LC and UV spectral and MS analyses of fraction III indicated the presence of glucosidic forms of cyanidin, peonidin, pelargonidin and their respective acylated counterparts.