Chitosan–GA scavenges carbon-centered radicals. (A) EPR spectra of POBN/R· spin adduct from: (a) the mixture of chitosan–GA (0.01 mM), POBN (25 μM), AAPH (15 mM), and PBS buffer pH 7.4 with UV exposure; (b) as in (a), but with GA (0.01 mM) instead of chitosan–GA; (c) as in (a), but with chitosan (0.01 mM); (d) as in (a), but without chitosan–GA, GA, and chitosan; (e) as in (a), but without AAPH; and (f) as in (b), but without AAPH. (B) Carbon-centered radicals scavenging capacity of GA (●), chitosan–GA (▲), and chitosan (■). Results are mean ± SD (n = 3).