In the current study, a series of new (2S,3S)-2-(4-isopropylbenzyl)-2-methyl-4-nitro-3-phenylbutanals (FM1-6) with their corresponding carboxylic acid analogues (FM7-12) has been synthesized. Initially, the aldehydic derivatives were isolated in the diastereomeric form, and the structures were confirmed with NMR, MS and elemental analysis. Based on the encouraging results in in vitro COX 1/2, 5-LOX and antioxidant assays, we oxidized the compounds and obtained the pure single (major) diastereomer for activities. Among all the compounds, FM4, FM10 and FM12 were the leading compounds based on their potent IC50 values. The IC50 values of compounds FM4, FM10 and FM12 were 0.74, 0.69 and 0.18 µM, respectively, in COX-2 assay. Similarly, the IC50 values of these three compounds were also dominant in COX-1 assay. In 5-LOX assay, the majority of our compounds were potent inhibitors of the enzyme. Based on the potency and safety profiles, FM10 and FM12 were subjected to the in vivo experiments. The compounds FM10 and FM12 were observed with encouraging results in in vivo analgesic and anti-inflammatory models. The molecular docking studies of the selected compounds show binding interactions in the minimized pocked of the target proteins. It is obvious from the overall results that FM10 and FM12 are potent analgesic and anti-inflammatory agents.
Keywords: 5-LOX; COX-2; Michael products; analgesic; anti-inflammatory; antioxidant; carrageenan.