Discovery of remogliflozin etabonate: A potent and highly selective SGLT2 inhibitor.

We optimized the structure of an active metabolite (1) of WAY-123783, which was obtained from mouse urine after oral administration, to improve selectivity for SGLT2 and oral bioavailability. O-glucoside derivative 24 (remogliflozin etabonate) was subsequently identified as a potent, highly selective, and orally available SGLT2 inhibitor.

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.

Identification of novel 1,2,3,6-tetrahydropyridyl-substituted benzo[d]thiazoles: Lead generation and optimization toward potent and orally active EP1 receptor antagonists.

Herein we described the design, synthesis and evaluation of a novel series of benzo[d]thiazole derivatives toward an orally active EP1 antagonist. Lead generation studies provided benzo[d]thiazole core from the four designed scaffolds. Optimization of this scaffold in terms of EP1 antagonist potency and ligand-lipophilicity efficiency (LLE; pIC50-clogP) led to a 1,2,3,6-tetrahydropyridyl-substituted benzo[d]thiazole derivative, 7r (IC50 1.1nM; LLE 4.7), which showed a good pharmacological effect when administered intraduodenally in a 17-phenyl trinor-PGE2 (17-PTP)-induced overactive bladder model in rats.

Novel pyrazolo[1,5-a]pyridines as orally active EP1 receptor antagonists: Synthesis, structure-activity relationship studies, and biological evaluation.

Novel pyrazolo[1,5-a]pyridine derivatives were designed, synthesized and evaluated as orally active EP1 antagonists for the treatment of overactive bladder. Matched molecular pair analysis (MMPA) allowed the design of a new series of pyrazolo[1,5-a]pyridine derivatives 4-6. Structure-activity relationships (SAR) studies of 4-6 were performed, leading to identification of the nanomolar-level EP1 antagonist 4c, which exhibited good pharmacological effect through intraduodenal (id) administration in a 17-phenyltrinor prostaglandin E2-induced bladder contraction model in rats.

Identification of Adenine and Benzimidazole Nucleosides as Potent Human Concentrative Nucleoside Transporter 2 Inhibitors: Potential Treatment for Hyperuricemia and Gout.

To test the hypothesis that inhibitors of human concentrative nucleoside transporter 2 (hCNT2) suppress increases in serum urate levels derived from dietary purines, we previously identified adenosine derivative 1 as a potent hCNT2 inhibitor (IC50 = 0.64 µM), but further study was hampered due to its poor solubility. Here we describe the results of subsequent research to identify more soluble and more potent hCNT2 inhibitors, leading to the discovery of the benzimidazole nucleoside 22, which is the most potent hCNT2 inhibitor (IC50 = 0.062 µM) reported to date. Compound 22 significantly suppressed the increase in plasma uric acid levels after oral administration of purine nucleosides in rats. Because compound 22 was poorly absorbed orally in rats (F = 0.51%), its pharmacologic action was mostly limited to the gastrointestinal tract. These findings suggest that inhibition of hCNT2 in the gastrointestinal tract can be a promising approach for the treatment of hyperuricemia.

Identification of 8-aminoadenosine derivatives as a new class of human concentrative nucleoside transporter 2 inhibitors.

Purine-rich foods have long been suspected as a major cause of hyperuricemia. We hypothesized that inhibition of human concentrative nucleoside transporter 2 (hCNT2) would suppress increases in serum urate levels derived from dietary purines. To test this hypothesis, the development of potent hCNT2 inhibitors was required. By modifying adenosine, an hCNT2 substrate, we successfully identified 8-aminoadenosine derivatives as a new class of hCNT2 inhibitors. Compound 12 moderately inhibited hCNT2 (IC50 = 52 ± 3.8 µM), and subsequent structure-activity relationship studies led to the discovery of compound 48 (IC50 = 0.64 ± 0.19 µM). Here we describe significant findings about structural requirements of 8-aminoadenosine derivatives for exhibiting potent hCNT2 inhibitory activity.

Hypouricemic effects of novel concentrative nucleoside transporter 2 inhibitors through suppressing intestinal absorption of purine nucleosides.

We have developed concentrative nucleoside transporter 2 (CNT2) inhibitors as a novel pharmacological approach for improving hyperuricemia by inhibiting intestinal absorption of purines. Dietary purine nucleosides are absorbed in the small intestines by CNTs expressed in the apical membrane. In humans, the absorbed purine nucleosides are rapidly degraded to their final end product, uric acid, by xanthine oxidase. Based on the expression profile of human CNTs in digestive tract tissues, we established a working hypothesis that mainly CNT2 contributes to the intestinal absorption of purine nucleosides. In order to confirm this possibility, we developed CNT2 inhibitors and found that (2R,3R,4S,5R)-2-(6-amino-8-{[3'-(3-aminopropoxy)-biphenyl-4-ylmethyl]-amino}-9H-purin-9-yl)-5-hydroxymethyl-tetrahydrofuran-3,4-diol (KGO-2142) and 1-[3-(5-{[1-((2R,3R,4S,5R)-3,4-dihydroxy-5-hydroxymethyl-tetrahydrofuran-2-yl)-1H-benzimidazol-2-ylamino]-methyl}-2-ethoxyphenoxy)-propyl]-piperidine-4-carboxylic acid amide (KGO-2173) were inhibitory. These CNT2 inhibitors had potent inhibitory activity against inosine uptake via human CNT2, but they did not potently interfere with nucleoside uptake via human CNT1, CNT3 or equilibrative nucleoside transporters (ENTs) in vitro. After oral administration of KGO-2173 along with [(14)C]-inosine, KGO-2173 significantly decreased the urinary excretion of radioactivity at 6 and 24h in rats. Since dietary purine nucleosides are not utilized in the body and are excreted into the urine rapidly, this decrease in radioactivity in the urine represented the inhibitory activity of KGO-2173 toward the absorption of [(14)C]-inosine in the small intestines. KGO-2142 almost completely inhibited dietary RNA-induced hyperuricemia and the increase in urinary excretion of uric acid in cebus monkeys. These novel CNT2 inhibitors, KGO-2142 and KGO-2173, could be useful therapeutic options for the treatment of hyperuricemia.