Blockade of the programmed cell death 1 (PD-1)/programmed cell death-ligand 1 (PD-L1) interaction is currently the focus in the field of cancer immunotherapy, and so far, several monoclonal antibodies (mAbs) have achieved encouraging outcomes in cancer treatment. Despite this achievement, mAbs-based therapies are struggling with limitations including poor tissue and tumor penetration, long half-life time, poor oral bioavailability, and expensive production costs, which prompted a shift towards the development of the small-molecule inhibitors of PD-1/PD-L1 pathways. Even though many small-molecule inhibitors targeting PD-1/PD-L1 interaction have been reported, their development lags behind the corresponding mAb, partly due to the challenges of developing drug-like small molecules. Herein, we report the discovery of a series of novel inhibitors targeting PD-1/PD-L1 interaction via structural simplification strategy by using BMS-1058 as a starting point. Among them, compound A9 stands out as the most promising candidate with excellent PD-L1 inhibitory activity (IC50 = 0.93 nM, LE = 0.43) and high binding affinity to hPD-L1 (KD = 3.64 nM, LE = 0.40). Furthermore, A9 can significantly promote the production of IFN-γ in a dose-dependent manner by rescuing PD-L1 mediated T-cell inhibition in Hep3B/OS-8/hPD-L1 and CD3-positive T cells co-culture assay. Taken together, these results suggest that A9 is a promising inhibitor of PD-1/PD-L1 interaction and is worthy for further study.
A palladium-catalyzed aza-Wacker cyclization of O-homoallyl benzimidates has been developed to afford a variety of useful 4-methylene-1,3-oxazine building blocks in moderate to good yields. The synthetic utility of the 4-methylene-1,3-oxazines...
An efficient aminofluorosulfonylation strategy was developed for the synthesis of various pyrazoline-functionalized aliphatic sulfonyl fluorides using β,γ-unsaturated hydrazones with sulfur dioxide and NFSI as the starting materials under mild conditions. The sulfonyl fluoride products could be successfully transformed into the corresponding sulfonate esters and amides via the sulfur(VI) fluoride exchange (SuFEx) click reactions. Preliminary mechanistic investigations demonstrate that the reaction operates through a radical cyclization/SO 2 insertion/fluorination cascade process.
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