Design, synthesis and anti-inflammatory evaluation of novel pyrrolo[2,3-d]pyrimidin derivatives as potent JAK inhibitors

Abstract

Aiming to develop potent JAK inhibitors, two series of 4-(1H-pyrazol-4-yl)-7H-pyrrolo[2,3-d]pyrimidine derivatives (8a-8p and 11a-11i) were designed and synthesized by coalescing various N-acylpiperidine motifs with baricitinib. The pharmacological results based on enzymatic and cellular assays identified the optimized compound 11e, which exerted over 90% inhibition rates against JAK1 and JAK2, and displayed the most compelling anti-inflammatory efficacy superior to baricitinib by inhibiting NO generation from LPS-induced RAW264.7 macrophages. Importantly, low cytotoxity of 11e was revealed by the IC₅₀ value of 88.2 μM against normal RAW264.7 cells. The binding mode of 11e with JAK1 and JAK2 identified the essential structural bases in accord with SARs analysis. Furthermore, cellular morphology observation and western blot analysis disclosed the ability of 11e to relieve cells inflammatory damage by significantly down-regulating LPS-induced high expression of JAK1, JAK2, as well as pro cytokine IL-1β. Together, 11e was verified as a promising lead for JAK inhibitors for the treatment of inflammatory diseases.