Synthesis and High-Throughput Screening of N-Acetyl-β-hexosaminidase Inhibitor Libraries Targeting Osteoarthritis.

C1 Nitrogen iminocyclitols are potent inhibitors of N-acetyl-β-hexosaminidases. Given hexosaminidases' important roles in osteoarthritis, we developed two straightforward and efficient syntheses of C1 nitrogen iminocyclitols from two readily available starting materials, d-mannosamine hydrochloride and the microbial oxidation product of fructose. A diversity-oriented synthetic strategy was then performed by coupling these core structures with various aldehydes, carboxylic acids, and alkynes to generate three separate libraries. High-throughput screening of the generated libraries with human N-acetyl-β-hexosaminidases produced only moderate inhibitory activities. However, the synthetic approach and screening strategy for these compounds will be applied to develop new potent inhibitors of human N-acetyl-β-hexosaminidases, particularly when combined with the structural information of these enzymes.