Nafizal Hossain

Spirocyclic compounds, potent CCR1 antagonists

Conformationally constrained spirocycles (17-23) and (31-36) were synthesised. In vitro data revealed that these compounds are CCR1 antagonists with sub-nanomolar potency. In a functional assay 22, 23 and 36 inhibited CCR1 mediated chemotaxis with an IC50 value of 2, 2.6 and 68nM, respectively.

Design, synthesis and structure activity relationships of spirocyclic compounds as potent CCR1 antagonists.

A series of CCR1 antagonists based upon spirocyclic compounds 1b and 2b were synthesised in which substituted aniline moiety was replaced with substituted benzamides. In vitro data revealed that CCR1 potency could be retained in such compounds.

Structure activity relationships of fused bicyclic and urea derivatives of spirocyclic compounds as potent CCR1 antagonists.

A series of fused bicyclic and urea derivatives of spirocyclic compounds were designed, synthesised and evaluated in vitro as potent CCR1 antagonists. In particular, 4 (7nM), 44 (1.3nM), 48 (0.89nM) and 50 (0.63nM) were the most potent hCCR1 antagonists in this series of compounds. Moreover, some of these substances demonstrated good rodent cross-over, especially 46 which exhibited very high rat CCR1 binding affinity with an IC50 value of 16nM.

Design, synthesis and structure-activity relationships of zwitterionic spirocyclic compounds as potent CCR1 antagonists.

A series of zwitterionic spirocyclic compounds were synthesised. In vitro data revealed that these compounds were potent CCR1 antagonists. In particular, 2, 4, 11 and 20 inhibited CCR1 mediated chemotaxis of THP-1 cells in a functional assay.

Potent and Orally Bioavailable Inverse Agonists of RORγt Resulting from Structure-Based Design

Retinoic acid receptor related orphan receptor γt (RORγt), has been identified as the master regulator of TH17-cell function and development, making it an attractive target for the treatment of autoimmune diseases by a small-molecule approach. Herein, we describe our investigations on a series of 4-aryl-thienyl acetamides, which were guided by insights from X-ray cocrystal structures. Efforts in targeting the cofactor-recruitment site from the 4-aryl group on the thiophene led to a series of potent binders with nanomolar activity in a primary human-TH17-cell assay. The observation of a DMSO molecule binding in a subpocket outside the LBD inspired the introduction of an acetamide into the benzylic position of these compounds. Hereby, a hydrogen-bond interaction of the introduced acetamide oxygen with the backbone amide of Glu379 was established. This greatly enhanced the cellular activity of previously weakly cell-active compounds. The best compounds combined potent inhibition of IL-17 release with favorable PK in rodents, with compound 32 representing a promising starting point for future investigations.