Electron spin resonance analysis of different mushroom parts and their hydroxyl radical scavenging activities assessed by spin trapping method

In this study, we analyzed the different parts of mushrooms using electron spin resonance (ESR) to identify radical species, and we examined their hydroxyl radical scavenging activities. The four kinds of mushrooms investigated in this study, Agrocybe cylindracea (Shakkiko1 and Shakkiko2), Grifola gargal, and Coprinus comatus were separated into caps, stipes, and bases of stipes. ESR spectra of all specimens consisted of signals originating from organic free radicals, Fe3+, Mn2+, and Cu2+ species. The cap showed the highest Fe content. The different mushroom body parts revealed different hydroxyl radical scavenging activity values, among which the C. comatus stipes were the highest. The radical scavenging activities of the evaluated specimens did not correlate with the Fe contents; however, a positive correlation with the Cu contents was observed.