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Lurasidone is a novel antipsychotic agent with high affinity for dopamine D(2), 5-hydroxyltryptamine 5-HT(2A), and 5-HT(7) receptors. Lurasidone has negligible affinity for histamine H(1) and muscarinic M(1) receptors, which are thought to contribute to side effects such as weight gain, sedation, and worsening of cognitive deficits. Our interests focus on why lurasidone has such high selectivity for only a part of these aminergic G-protein coupled receptors (GPCRs) and the different binding profile from ziprasidone, which has the same benzisothiazolylpiperazine moiety as lurasidone. In order to address these issues, we constructed structural models of lurasidone-GPCR complexes by homology modeling of receptors, exhaustive docking of ligand, and molecular dynamics simulation-based refinement of complexes. This computational study gave reliable structural models for D(2), 5-HT(2A), and 5-HT(7), which had overall structural complementarities with a salt bridge anchor at the center of the lurasidone molecule, but not for H(1) and M(1) owing to steric hindrance between the norbornane-2,3-dicarboximide and/or cyclohexane part of lurasidone and both receptors. By comparison with the structural models of olanzapine-GPCRs and ziprasidone-GPCRs constructed using the same computational protocols, it was suggested that the bulkiness of the norbornane-2,3-dicarboximide part and the rigidity and the bulkiness of the cyclohexyl linker gave lurasidone high selectivity for the desired aminergic GPCRs. Finally, this structural insight was validated by a binding experiment of the novel benzisothiazolylpiperazine derivatives. This knowledge on the structural mechanism behind the receptor selectivity should help to design new antipsychotic agents with preferable binding profiles, and the established computational protocols realize virtual screening and structure-based drug design for other central nervous system drugs with desired selectivity for multiple targets.

Pulmonary fibrosis is a progressive and lethal lung disease characterized by accumulation of ECM and loss of pulmonary function. However, no cure exists for this disease, and current treatments often fail to slow its progression or relieve its symptoms. We have previously reported that the anti-fibrotic agent SMP-534 has beneficial effects on renal fibrosis in animal model of nephropathy. In this study, we examined whether SMP-534 has beneficial effects on pulmonary fibrosis in bleomycin-treated hamsters. Treatment with SMP-534 [low dose (70 mg/kg) or high dose (110 mg/kg)] counteracted inhibition of body weight increase induced by bleomycin. In addition, SMP-534 significantly inhibited bleomycin-induced increase in lung hydroxyproline level, an index of collagen formation. Moreover, SMP-534 significantly ameliorated histological pulmonary fibrotic changes induced by bleomycin. The results of this study indicate that the anti-fibrotic agent SMP-534 may offer a new therapeutic option for the treatment of pulmonary fibrosis.

The number of patients with chronic kidney disease (CKD) has continuously grown worldwide. Treatment with antihypertensive agents reduces the rate of progression of CKD, however, there is still a large unmet need to develop strategies for the treatment of CKD. Although we have previously reported that the antifibrotic agent, SMP-534 inhibits the progression of CKD, it is unknown whether combination therapy with SMP-534 and antihypertensive agent shows additive effects on CKD. In present study, we examined whether combination therapy with SMP-534 and the antihypertensive agent, lisinopril is more effective than single therapy with SMP-534 or lisinopril on five-sixths nephrectomized (5/6Nx) rat model. Combination therapy with SMP-534 (50 mg/kg) and lisinopril (5 mg/kg) significantly decreased urinary albumin excretion, blood urea nitrogen (BUN) and serum creatinine and increased creatinine clearance in 5/6Nx rats. On the other hands, single treatment with SMP-534 or lisinopril did not improve renal function at this dose. In addition, combination therapy with SMP-534 and lisinopril significantly decreased extracellular matrix (ECM) accumulation in renal glomeruli and tubulointerstitial injury. These data suggest that combination therapy with an antifibrotic agent and an antihypertensive agent may offer a new therapeutic option for suppressing the progression of CKD.

Background/Aims: Diabetic nephropathy is the main cause of end-stage renal disease. Previously we have demonstrated that SMP-534 (an antifibrotic agent) prevents the development of diabetic nephropathy in db/db mouse and that combined treatment with SMP-534 and losartan (antihypertensive agents) markedly prevents the development of diabetic nephropathy compared with single treatment. SMP-534 or losartan was prophylactically administered to db/db mice before the onset of diabetic nephropathy. In the present study, we evaluated the efficacy of combined treatment when administration was started after the onset of diabetic nephropathy. Methods:db/db mice were raised untreated until 17 weeks of age, by which time increase of urinary albumin was noted, and then treated with SMP-534 and/or losartan for another 8 weeks. Biochemical and histological analyses were performed at 25 weeks of age. Results: Combined treatment with SMP-534 and losartan markedly prevented the increase ofurinary albumin and ameliorated the progression of mesangial matrix expansion, even when administration was started long after the increase of urinary albumin. Conclusion: The study results indicate that a combination of SMP-534 and losartan might be a valuable therapeutic approach for the treatment of diabetic nephropathy even when administration is started after the onset of diabetic nephropathy.

Diabetic nephropathy is currently the most common cause of end-stage renal disease. Diabetic nephropathy patients, whether insulin dependent or not, develop fibrotic changes in glomeruli that manifest as overt nephropathy. Previously, we demonstrated that 5-chloro-2-{(1E)-3-[2-(4-methoxybenzoyl)-4-methyl-1H-pyrrol-1-yl]prop-1-en-1-yl}- N-(methylsulfonyl)benzamide (SMP-534) reduces extracellular matrix (ECM) production induced by transforming growth factor-β (TGF-β) in vitro and prevents the accumulation of ECM in glomeruli in rat Thy-1 nephritis models. In this study, we examined the long-term effects of SMP-534 on renal insufficiency and glomerulosclerosis in db/db mice, which are models of type 2 diabetes. A diet containing SMP-534 was given to the mice from the age of 9 to 25 wk, and blood and urine analysis were performed at 8, 17, and 25 wk. At the end of study, kidney tissues were analyzed histologically. Treatment with SMP-534 dose dependently suppressed the increase of urinary albumin and type IV collagen excretion in db/db mice. The renal histological analysis showed that SMP-534 dose dependently suppressed the increase of mesangial expansion in the kidney. In the immunohistological analysis, fibronectin and type IV collagen expression were lower in SMP-534-treated db/db mice compared with vehicle-treated db/db mice. This study suggested that SMP-534 ameliorated the increase of ECM production in kidney of db/db mice, possibly through the inhibition of TGF-β action. Hence, antifibrotic agents such as SMP-534 might be a new therapeutic option for the treatment of diabetic nephropathy.

Background/Aims: Diabetic nephropathy is now the most common cause of end-stage renal disease. It is also clear that the current therapy, angiotensin II blockage, cannot prevent the progression of diabetic nephropathy. We had previously demonstrated that an antifibrotic agent, SMP-534, reduced extracellular matrix production induced by transforming growth factor-β in vitro, and that SMP-534 prevented renal fibrosis and urinary albumin in diabetic db/db mice via a nonantihypertensive mechanism. We expected that combined use of SMP-534 and losartan would produce a more highly renoprotective action. Methods: We examined the effects of combined treatment with SMP-534 and losartan on urinary albumin and glomerular fibrosis in db/db mice. Diet containing these agents was provided from age 9 to 25 weeks. Blood and urine analyses were performed at 8, 17, and 25 weeks. At the end of the study, kidney tissues were histologically analyzed. Results: SMP-534 significantly suppressed an increase in urinary albumin excretion and ameliorated the progression of glomerular fibrosis in db/db mice, whereas losartan did not. Combined treatment with SMP-534 and losartan markedly prevented the increase of urinary albumin excretion compared with treatment with either SMP-534 or losartan alone. In contrast, renal histological analysis revealed that combined treatment did not significantly prevent an increase of mesangial expansion in the kidney compared with treatment with SMP-534 alone. Conclusion: A combination of the two agents, SMP-534 and losartan, might be a valuable therapeutic approach for the treatment of diabetic nephropathy.

Transforming growth factor-β (TGF-β) is a potent fibrotic factor responsible for the synthesis of extracellular matrix (ECM) and is implicated as the major determinant in pathogenesis of chronic fibroses, including kidney. The novel small compound SMP-534 reduced ECM production induced by TGF-β in fibroblast cells. SMP-534 inhibited TGF-β-induced p38 mitogen-activated protein kinase (p38) activation but did not inhibit epidermal growth factor (EGF)-induced extracellular signal-related kinase (ERK) activation. We also found that oral administration of SMP-534 dose dependently lowered hydroxyproline contents in the cortical region of the kidney in rat anti-Thy-1 nephritis models. In periodic acid-Schiff staining of kidney sections, ECM accumulation was reduced by SMP-534 treatment. These data indicate that SMP-534 has potential in therapy for fibrotic diseases, including nephropathy.

A series of substituted oxindole derivatives of SM-130686 was synthesized and evaluated as ghrelin receptor agonists. Modification of the substituents on the C3-aromatic part of the oxindole led to compounds with subnanomolar binding affinities. Compound 4i (IC 50 = 0.02 nM) was orally active at low doses and showed in vivo activity when orally administered, 2 mg/kg twice a day for 4 days, as evidenced by significant body weight gain.

A series of substituted oxindole derivatives was synthesized and evaluated for growth hormone (GH) releasing activity using cultured rat pituitary cells. (+)-6-Carbamoyl-3-(2-chlorophenyl)-(2-diethylaminoethyl)-4-trifluoromethyloxindole (SM-130686, 37S) was found to have potent activity (EC(50) = 3.0 nM), while the other enantiomer 37R had reduced activity. The absolute configuration of 37S was confirmed by X-ray crystallographic analysis. Compound 37S showed a good pharmacokinetic profile in rats with 28% oral bioavailability at 10 mg/kg and excellent in vivo activity as evidenced by a significant weight gain after 4 days of oral administration at 10 mg/kg twice a day. Compound 37S displaced the binding of (35)S-MK-677 to human GHS-R with an IC(50) value of 1.2 +/- 0.2 nM.

In our search for new PPARα/γ agonists, we designed and synthesized a series of benzoylazole-based carboxylic acids. Compound 9 showed potent PPARγ partial agonistic activity with modest PPARα agonistic activity. The sodium salt of 9 (9Na) demonstrated potent efficacy in lowering both blood glucose and lipids in an animal model without causing significant body weight gain, a well-known side effect associated with PPARγ full agonists.

Substituted eneyne-allenes 1 , 6 , and 7 underwent Bergman type cyclization at 37 °C, whereas 5 was almost stable at the temperature. Compounds 1 and 7 showed DNAcleaving activities.

Background/Aims: Chronic kidney disease (CKD) is the common cause of end-stage renal disease. Antihypertensive agents are clinically used to inhibit the progression of CKD. However, these agents cannot completely prevent progression to renal failure. We have previously reported that 5-chloro-2-{(1E)-3-[2-(4-methoxybenzoyl)-4-methyl-1H- pyrrol-1-yl]prop-1en-1-yl}-N-(methylsulfonyl)benzamide (SMP-534) improves renal disease and prevents the production of extracellular matrix in vitro. Additionally, SMP-534 inhibits glomerular fibrosis and provides renoprotection in vivo. In the present study, we investigated the effect of SMP-534 on renal dysfunction in a 5/6 nephrectomized (5/6Nx) rat model. Method: Five groups of rats were studied: sham operated, 5/6Nx + vehicle, 5/6Nx + SMP-534 30 mg/kg, 5/6Nx + SMP-534 60 mg/kg and 5/6Nx + SMP-534 90 mg/kg. Treatment with SMP-534 began 13 weeks after surgery, when hypertension and renal insufficiency had developed. Serum creatinine, blood urea nitrogen levels, creatinine clearance and urinary albumin were measured at specific time points. Results: Serum creatinine and blood urea nitrogen levels were significantly reduced in SMP-534-treated groups. In addition, SMP-534 dose-dependently suppressed the increase in urinary albumin excretion observed in 5/6Nx rats. Moreover, survival rates were improved in SMP-534-treated groups. Conclusion: We have shown in this study that chronic oral administration of SMP-534 improves renal dysfunction in 5/6Nx rats. These findings indicate that SMP-534 may be a new therapeutic agent for the treatment of CKD.

Hypothalamic hormones physiologically regulate pulsatile release of growth hormone (GH) from the anterior pituitary gland. Since the discovery of these hormones in the 1970s, several new chemically synthesized peptidyl and non-peptidyl derivatives have been proved to stimulate and amplify GH secretion, and this series of molecules has been named the growth hormone secretagogues (GHSs). One of these compounds led to the discovery of a GPCR-type receptor for GHSs (GHS-R), and subsequently the endogenous ligand for the receptor has been identified, and is referred to as ghrelin. The identification of GHSs as physiological regulators of GH secretion encouraged us to examine our GHSs pharmacologically. We previously reported that novel oxindole derivatives have been identified as GHS-R agonists from our internal chemical library. Among these derivatives, (+)-6-carbamoyl-3-(2-chlorophenyl)-(2-diethylaminoethyl)-4-trifluoromethyloxindole (SM-130686, 37S) was found to have potent activity in vitro with a good pharmacokinetic profile in rats (bioavailability of 28%). In this article, we review the synthesis and pharmacological evaluation of SM-130686. SM-130686 binds specifically to GHS-R and increases the Ca(2+) concentration in Chinese hamster ovary cells expressing recombinant GHS-R. Maximal enhancement of the intracellular Ca(2+) concentration induced by SM-130686 treatment was approximately 55% that induced by ghrelin, suggesting that SM-130686 may be a partial GHS-R agonist. Also, in in vivo studies, oral administration of SM-130686 increased body length and fat-free mass gain. We compare the pharmacological profile of SM-130686 with other GHSs, including GHRH and ghrelin, and discuss the therapeutic usefulness of GHSs against several disorders, as well as for treatment of GH deficiency.

The purpose of this study was to clarify the in vitro pharmacological profile and the in vivo activity of (3 S )-7-chloro-3-[2-((1 R )-1-carboxyethoxy)-4-aminomethylphenyl]aminocarbonylmethyl-1,3,4,5-tetrahydrobenz[c,d]indole-2-carboxylic acid hydrochloride (SM-31900). SM-31900 inhibited the binding of [ 3 H]glycine and [ 3 H]5,7-dichlorokynurenic acid, radioligands for the N -methyl- d -aspartate (NMDA) receptor glycine-binding site, to rat brain membranes in a competitive manner, with K i values of 11±2 and 1.0±0.1 nM, respectively, and completely prevented the binding of [ 3 H]dizocilpine (MK-801), a radioligand for the NMDA receptor channel site. In cultures of rat cortical neurons, SM-31900 markedly prevented the neuronal cell death induced by transient exposure to glutamate, in a concentration-dependent manner. Its neuroprotective potency was much stronger than those of other glycine-binding site antagonists (4- trans -2-carboxy-5,7-dichloro-4-phenylaminocarbonylamino-1,2,3,4-tetrahydroquinoline (L-689,560), 5,7-dichlorokynurenic acid, and 7-chlorokynurenic acid). Furthermore, SM-31900 showed anticonvulsant activity when administered systemically, unlike other antagonists. These data indicate that SM-31900 is a systemically active antagonist with high affinity for the NMDA receptor glycine-binding site.

SM-130686, an oxindole derivative, is a novel orally active GH secretagogue (GHS) which is structurally distinct from previously reported GHSs such as MK-677, NN703 and hexarelin. SM-130686 stimulates GH release from cultured rat pituitary cells in a dose-dependent manner. Half-maximum stimulation was observed at a concentration of 6.3+/-3.4 nM. SM-130686-induced GH release was inhibited by a GHS antagonist, but not by a GH-releasing hormone antagonist. SM-130686 dose-dependently inhibited the binding of radiolabeled ligand, (35)S-MK-677, to human GHS receptor 1a (IC(50)=1.2 nM). This indicates that SM-130686 stimulates GH release through the GHS receptor. The effect of a single oral administration of SM-130686 on GH release in pentobarbital-anesthetized rats was studied. After treatment with 10 mg/kg SM-130686, plasma GH concentrations measured by radioimmunoassay significantly increased, reaching a peak at 20-45 min, and remained above baseline during the experimental period (60 min). The anabolic effect of repetitive SM-130686 administration was studied in rats. Rats received 10 mg/kg SM-130686 orally twice a day and were weighed every day for 9 days. At day 9 there was a significant increase in both the body weight and the fat free mass (19.5+/-2.1 and 18.1+/-7.5 g respectively). Serum IGF-I concentration was also significantly elevated 6 h after the last dose of SM-130686. An endogenous GHS ligand for the GHS receptor has recently been identified from stomach extract and designated as ghrelin. The GH-releasing activity in vitro relative to ghrelin (100%) was about 52% for SM-130686. It is likely that SM-130686 is a partial agonist for the GHS receptor. In summary, we describe here an orally active GHS, SM-130686, which acts through the GHS receptor. Repetitive administration of SM-130686 to rats, similar to repetitive administration of GH, significantly increased the fat free mass by an amount almost equal to the gain in body weight.

Acyclic conjugated allenylphosphine oxide 4b prepared by three step operations was stable at ambient temperature and underwent Bergman type cyclization to form biradical 5b at 37 °C.