Preliminary structure activity relationships and a superimposition of the best compound with the active conformation of donepezil have revealed structural features that have been used in the design of more potent N-benzylpiperidine inhibitors bearing an 8-substituted cafragmentrandent and a methoxymethyl linker.
The best compound, a di-iodinated derivative, was 10-fold more potent than verapamil, with a half-maximal effective concentration (EC50) value for cytotoxicity of 1.1 μM for MRP1-transfected BHK-21 cells compared to 54.7 μM for parental BHK-21 cells, giving a selectivity ratio (SR) of 50.
In a dose response assay, NSC 37408 (6,7-dihydroxy-1-benzofuran-3-one), our best compound, exhibited an IC50 of 3 μM in the presence of 100 nM copper.
These compounds generally inhibited NaV1.8 with IC50s in the sub-micromolar range and had some selectivity for NaV1.8 over other Nav isoforms with the best compound displaying a 5-fold and 20-fold greater potency for NaV1.8 over NaV1.2 and NaV1.5, respectively.
The best compound displayed an activity 6-fold higher than chloroquine.
Our studies have shown that modifications of this compound are tolerated and result in improved inhibitors, with the best compound having an IC50 of 0.23 μM.
The best compound has an IC50 of 200 nM and EC50 of 100 nM, which is a significant improvement over the starting inhibitor (1).
The best compound has an IC50 value of 12 nM against aggrecanase, with the K i values for MMP-1, MMP-2 and MMP-9 in a micromolar range (4 33 μM), and it is orally available [ 75].
For example, if we have a set of drug candidates that target proteins in a pathway, our methods can be used to asses which is the best compound to use as a single agent or in combination.
The best compound, 6j, with a tryptophan amino moiety and piperidine nitroxyl radical showed GI50 values of 13.7 15.0 μM, and was fivefold more potent than GA.
