Synthesis, pharmacological evaluation and molecular docking of novel R-/S-2-(2-hydroxypropanamido)-5-trifluoromethyl benzoic acid as dual anti-inflammatory anti-platelet aggregation agents

Abstract

R-/S-2-(2-hydroxypropanamido) benzoic acid (R-/S-HPABA), marine-derived anti-inflammatory antiplatelet drugs, were initially synthesised in our group. However, preliminary research showed that R-/S-HPABA were eliminated rapidly because of extensive hydroxylation metabolism of phenyl ring in vivo. In order to reduce significant hydroxylation metabolism to improve pharmacological activity and bioavailability, trifluoromethyl group was incorporated into R-/S-HPABA to synthesise R-/S-2-(2-hydroxypropanamido)-5-trifluoromethyl benzoic acid (R-/S-HFBA), respectively. The purposes of this study were to report the synthesis of R-/S-HFBA and compare the anti-inflammatory antiplatelet effect and pharmacokinetic properties of R-/S-HFBA with those of R-/S-HPABA. Carrageenan-induced rat paw edema assay was used for the evaluation of the anti-inflammatory activity. R-/S-HFBA showed better results in inhibiting edema and were able to prolong the anti-inflammatory effect after carrageenan injection. The antiplatelet aggregation activity of R-/S-HFBA and R-/S-HPABA was studied on arachidonic acid-induced platelet aggregation of rabbit platelet-rich plasma. The aggregation inhibition rate of R-/S-HFBA was significantly (p < 0.05) higher than that of R-/S-HPABA, respectively. Molecular docking study revealed that R-/S-HFBA possess more potent binding affinity with COX-1/COX-2 than R-/S-HPABA, respectively, and that the presence of trifluoromethyl group leads to increase in activity of R-/S-HFBA. R-/S-HFBA also afford more favorable pharmacokinetic properties than R-/S-HPABA, respectively, such as higher C_max, larger AUC_0-∞, and longer t_1/2, which, as expected, are more metabolically stable.

Keywords: Anti-inflammatory; Antiplatelet; Molecular docking; R-/S-2-(2-hydroxypropanamido) benzoic acid; R-/S-2-(2-hydroxypropanamido)-5-trifluoromethyl benzoic acid.