The in vitro anti-inflammatory activity of compounds 1, 2, 5, and 6 were evaluated by suppressing
N-formyl-methionyl-leucylphenylalanine/cytochalasin B (FMLP-CB)-induced superoxide anion generation
and elastase release in human neutrophils (Table 4). Among them, compound 2 was found to displaypotent inhibitory effects on generation of superoxide anion (IC50 0.22 ± 0.03 μg/mL) and the release of
elastase (IC50 0.48 ± 0.11 μg/mL) by human neutrophils at a concentration of 10 μg/mL.