Design, synthesis, anti-trypsin and anti-inflammatory evaluation of new guanidinobenzoic acid ester derivatives

Herein, we designed a series of guanidinobenzoic acid ester derivatives on the basis of approved AP drugs, such as nafamostat, gabexate and camostat, and evaluated their inhibitory effects on trypsin and anti-inflammatory activity. Among them, five compounds (6a, 6c–6e, 7j) showed excellent inhibitory effects on trypsin with IC50 values of 0.0756 μM to 0.1227 μM, which are more potent than nafamostat and gabexate. Moreover, compounds 6a, 6b and 6c also showed significant inhibitory potency against the pro-inflammatory molecule NO with IC50 values of 1.618 μM, 2.276 μM, and 3.022 μM, respectively. Consequently, the potential lead compounds simultaneously with anti-trypsin and anti-inflammatory activities were identified, which would profit further structural optimization for the treatment of AP.