Rational Design, Synthesis, and Potency of N-Substituted Indoles, Pyrroles, and Triarylpyrazoles as Potential Fructose 1,6-Bisphosphatase Inhibitors

By using computer modeling and lead structures from our earlier SAR results, a broad variety of pyrrole-, indole-, and pyrazole-based compounds were evaluated as potential fructose 1,6-bisphosphatase (FBPase) inhibitors. The docking studies yielded promising structures, and several were selected for synthesis and FBPase inhibition assays: 1-[4-(trifluoromethyl)-benzoyl]-1H-indole-5-carboxamide, 1-(alpha-naphthalen-1-ylsulfonyl)-7-nitro-1H-indole, 5-(4-carboxyphenyl)-3-phenyl-1-[3-(tri-fluoromethyl)phenyl]-1H-pyrazole, 1-(4-carboxyphenylsulfonyl)-1H-pyrrole, and 1-(4-carbomethoxyphenylsulfonyl)-1H-pyrrole were synthesized and tested for inhibition of FBPase. The IC50 values were determined to be 0.991 and 1.34 mu m, and 575, 135, and 32 nm, respectively. The tested compounds were significantly more potent than the natural inhibitor AMP (4.0 mu m) by an order of magnitude; indeed, the best inhibitor showed an IC50 value toward FBPase more than two orders of magnitude better than that of AMP. This level of activity is virtually the same as that of the best currently known FBPase inhibitors. This work shows that such indole derivatives are promising candidates for drug development in the treatment of type II diabetes.