(4-Piperidinylphenyl)aminoethyl amides as a novel class of non-covalent cathepsin K inhibitors

Organic carbamates in drug design and medicinal chemistry

The carbamate group is a key structural motif in many approved drugs and prodrugs. There is an increasing use of carbamates in medicinal chemistry and many derivatives are specifically designed to make drug-target interactions through their carbamate moiety. In this Perspective, we present properties and stabilities of carbamates, reagents and chemical methodologies for the synthesis of carbamates, and recent applications of carbamates in drug design and medicinal chemistry.

Potent and selective cathepsin K inhibitors

A novel series of cathepsin K inhibitors derived from Novartis compound I is described. Optimization of the P1, P3, and P1' units led to the identification of 4-aminophenoxyacetic acid 24b with an IC(50) value of 4.8 nM, which possessed an excellent selectivity over other human cathepsins and good pharmacokinetic (PK) properties. Oral administration of compound 24b to ovariectomized (OVX) rats showed a trend toward an improvement of bone mineral density (BMD) in the femur bone.

Arylamine based cathepsin K inhibitors: investigating P3 heterocyclic substituents

A modification of novel cathepsin K inhibitors I was carried out. The structural design was aimed at reducing the lipophilic character of compounds I for obtaining better pharmacokinetic profiles. This modification afforded several less lipophilic compounds with good inhibitory activities and pharmacokinetic profiles, although the enzyme selectivity over cathepsin S was left at issue.

4-Aminophenoxyacetic acids as a novel class of reversible cathepsin K inhibitors

We have designed and synthesized a novel series of 3-biphenylamino acid amides as cathepsin K inhibitors based on compound I. In these inhibitors, we have discovered 4-aminophenoxyacetic acids 43 and 47 with good IC(50) values, although lipophilic groups are favorable for the hydrophobic S1' pocket.

Synthesis and evaluation of cis-hexahydropyrrolo[3,2-b]pyrrol-3-one peptidomimetic inhibitors of CAC1 cysteinyl proteinases

A stereoselective synthesis of functionalised cis-hexahydropyrrolo[3,2-b]pyrrol-3-ones has been developed through Fmoc and Cbz-protected intermediates 5 and 6. Building blocks 5 and 6 were prepared via the intramolecular cyclisation of anti-epoxide 17. The intramolecular reaction occurred exclusively through the anti-epoxide to provide the 5,5-cis-fused bicycle, whereas the syn-epoxide, which theoretically would provide the 5,5-trans-fused bicycle, remained unchanged. These experimental observations are consistent with a key design element that we have introduced within this novel bicyclic ketone scaffold. Our bicyclic design strategy provides chiral stability to the bridgehead stereocentre that is situated alpha to the ketone because the cis-fused geometry is both thermodynamically and kinetically stable. Building blocks 5 and 6 have been utilised in both solid phase and solution phase syntheses of peptidomimetics 22, 36-40, which exhibit potent in vitro inhibition against a range of CAC1 cysteinyl proteinases. Compound 22, a potent and selective inhibitor of human cathepsin K exhibited good primary DMPK properties along with promising activity in an in vitro cell-based human osteoclast assay of bone resorption.