Identification of novel glycine sulfonamide antagonists for the EP1 receptor

Discovery of novel pyrazolo[1,5-a]pyridine-based EP1 receptor antagonists by scaffold hopping: Design, synthesis, and structure-activity relationships

A scaffold-hopping strategy towards a new pyrazolo[1,5-a]pyridine based core using molecular hybridization of two structurally distinct EP₁ antagonists, followed by structure-activity relationship-guided optimization, resulted in the identification of potent EP₁ antagonists exemplified by 4c, 4f, and 4j, which were shown to reduce pathological intravesical pressure in rats when administered at 1mg/kg iv.

Synthesis, characterization and in vivo evaluation of [(62)Zn]-benzo-δ-sultam complex as a possible pet imaging agent

OBJECTIVE

The development of a new tracer based on the cyclic sulfonamides (sultams) was investigated.

METHODS

3-(Methoxy-phenyl-methyl)-1,6-dimethyl-1H benzo[c][1,2] thiazine 2,2-dioxide (benzo-δ-sultam) was synthesized and characterized by elemental analysis, FT-IR spectroscopy and single crystal X-ray structure determination. The prepared cyclic sulfonamide was labeled with non-commercial (62)Zn radioisotope for fast in vivo targeting and Coincidence imaging purposes (radiochemical purity 97 % ITLC, 96 % HPLC, specific activity 20-23 GBq/mmol). In vivo biodistribution of the final complex was investigated in Sprague Dawley(®) rats bearing fibro sarcoma tumor after 2, 4 and 8 h post injection and compared with free Zn(+2) cation.

RESULTS

Using instant paper chromatography method, the physicochemical properties of labeled compounds were found sufficiently stable in organic phases, e.g. a human serum, to be reliably used in bioapplications.

CONCLUSIONS

The complex exhibited a rapid as well as high tumor uptake (tumor to blood ratio 4.38 and tumor to muscle ratio 9.63) resulting in an efficient tumor targeting agent.

Parallel syntheses of eight-membered ring sultams via two cascade reactions in water

From vinyl sulfonamides as precursors to vinyl sulfonamide epoxides, two cascade reaction protocols were developed to synthesize eight-membered ring sultams in water. These protocols employ intermolecular Michael addition by NaOH or NaHS in water, followed by rapid proton transfer and intramolecular 8-endo-tet epoxide ring-opening to give medium-size sultams selectively in one-pot. Novel core structures and high synthetic efficiency make these cascade reactions highly suitable for sultam library production. Both reactions proceeded well and afforded the respective sultams in good yields under environmentally friendly conditions.

Discovery of a novel indole series of EP1 receptor antagonists by scaffold hopping

We describe the medicinal chemistry approach that generated a novel indole series of EP(1) receptor antagonists. The SAR of this new template was evaluated and culminated in the identification of compound 12g which demonstrated in vivo efficacy in a preclinical model of inflammatory pain.

Identification and optimization of novel 1,3,4-oxadiazole EP1 receptor antagonists

A novel series of oxadiazole EP1 receptor antagonists was identified by replacing the amide of a known glycine sulfonamide derivative with a 1,3,4-oxadiazole. Optimization of the substitution patterns on the three aromatic rings led to the identification of high affinity EP1 receptor antagonists. The derivative with highest affinity displayed a binding IC50 of 2.5 nM (pIC50 8.6).