Synthesis and pharmacological evaluation of novel arylpiperazine derivatives as nonsteroidal androgen receptor antagonists

The search for novel antiandrogens by high-throughput screening (HTS) of the Yamanouchi chemical library led to the discovery of the lead compound (5), which possesses an arylmorpholine moiety. Through the optimization of the lead compound (5), we have found a series of novel arylpiperazine derivatives. Among them, 4-[4-cyano-(3-trifluoromethyl)phenyl]-N-(4-fluorophenyl)piperazine-1-carboxamide (22; YM-92088) exhibited a potent AR antagonistic activity with an IC(50) value of 0.47 microM in the reporter assay, which is more potent than bicalutamide (4) which has an IC(50) value of 0.89 microM.     

A novel class of inhibitors for human steroid 5alpha-reductase: synthesis and biological evaluation of indole derivatives. II

In a search for novel nonsteroidal inhibitors of human prostatic 5alpha-reductase, we found a new series of indole derivatives that showed potent inhibitory activities for the human enzyme. Among them, 4-[(1-benzyl-1H-indol-5-yl)oxyl-3-chlorobenzoic acid (2d, YM-32906) showed more potent inhibitory activity than finasteride with an IC50 value of 0.44 nM. 3-Chloro-4-[[1-(4-phenoxybenzyl)-1H-indol-5-yl]oxy]benzoic acid (2m) showed inhibitory activities for both human and rat prostatic 5alpha-reductase with IC50 values of 2.1 and 73 nM, respectively. The synthesis and structure-activity relationships of these indole derivatives are presented.     

A novel class of inhibitors for human and rat steroid 5alpha-reductases: synthesis and biological evaluation of indoline and aniline derivatives. III

While searching for novel nonsteroidal inhibitors of human and rat prostatic 5alpha-reductases, we found a new series of indoline and aniline derivatives that showed potent inhibitory activities for both enzymes. Among them, 3-chloro-4-?[1-(4-phenoxybenzyl)indolin-5-yl]oxylbenzoic acid (2e, YM-36117) showed a more potent inhibitory activity for the human enzyme than ONO-3805 with an IC50 value of 5.3 nM and a reduced rat prostatic dihydrotestosterone (DHT) concentration by oral administration. The synthesis and the structure-activity relationships of these indoline and aniline derivatives are presented.     

Synthesis and pharmacological evaluation of 1-alkyl-N-[(1R)-1-(4-fluorophenyl)-2-methylpropyl]piperidine-4-carboxamide derivatives as novel antihypertensive agents

We synthesized and evaluated inhibitory activity against T-type Ca(2+) channels for a series of 1-alkyl-N-[(1R)-1-(4-fluorophenyl)-2-methylpropyl]piperidine-4-carboxamide derivatives. Structure-activity relationship studies have revealed that the isopropyl substituent at the benzylic position plays an important role in exerting potent inhibitory activity, and the absolute configuration of the benzylic position was found to be opposite that of mibefradil, which was first launched as a new class of T-type Ca(2+) channel blocker. Oral administration of N-[(1R)-1-(4-fluorophenyl)-2-methylpropyl]-1-[2-(3-methoxyphenyl)ethyl]piperidine-4-carboxamide (17f) lowered blood pressure in spontaneously hypertensive rats without inducing reflex tachycardia, an adverse effect often caused by traditional L-type Ca(2+) channel blockers.     

Androgen receptor antagonists and anti-prostate cancer activities of some synthesized steroidal candidates

In continuation of our previous work, a novel series of steroid derivatives were synthesized and their androgen receptor (AR) antagonist activities and in vivo antiandrogenic properties were evaluated. Twenty-one heterocyclic derivatives containing a cyanopyrane ring fused to a steroidal moiety were conveniently synthesized and screened for their antagonistic, antiandrogen and prostate anticancer activities comparable to that of bicalutamide as the reference control. Some of the compounds exhibited better antagonistic, antiandrogen and prostate anticancer activities than the reference controls. Initially the acute toxicity of the compounds was assayed via the determination of their LD(50). Synthetic steroidal structures fused to a substituted cyanopyrane ring seem to be a promising approach in the search for novel leads for potent antagonistic, antiandrogen and prostate anticancer agents.     

Synthesis and anti-hyperlipidemic evaluation of N‑(benzoylphenyl)-5-fluoro-1H-indole-2-carboxamide derivatives in Triton WR-1339-induced hyperlipidemic rats

The lipid-lowering activity of a series of novel N-(benzoylphenyl)-5-fluoro-1H-indole-2-carboxamide derivatives has been studied in Triton WR-1339-induced hyperlipidemia in rats. The test animals were divided into four groups: control, hyperlipidemic, compound + 4% DMSO [C1: N-(2-benzoylphenyl)-5-fluoro-1H-indole-2-carboxamide (1), C2: N-(3-benzoylphenyl)-5-fluoro-1H-indole-2-carboxamide (2), C3: N-(4-benzoylphenyl)-5-fluoro-1H-indole-2-carboxamide (3)]-treated and bezafibrate (BF)-treated. At a dose of 15 mg/Kg body weight, compounds 2, 3 and BF significantly reduced elevated plasma triglycerodes levels after 12 h. Moreover, high density lipoprotein-cholesterol levels were significantly increased in all treated groups after 12 h compared to the hyperlipidemic control group, except for C1 which was inactive. In sum, it may be stated that the results of the present study demonstrated new properties of some N-(benzoylphenyl)-5-fluoro-1H-indole-2-carboxamide derivatives as potent lipid lowering agents and these beneficial activities may contribute to their cardioprotective and antiatherosclerotic role.     

Highly potent and orally active non-peptide arginine vasopressin antagonists for both V1A and V2 receptors: synthesis and pharmacological properties of 4'-[(4,4-difluoro-5-methylidene-2,3,4,5-tetrahydro-1H-1-benzoazepin-1-y l)carbonyl]-2-phenylbenzanilide derivatives

A series of compounds structurally related to 4'-[(4,4-difluoro-5-methylidene-2,3,4,5-tetrahydro-1H-1-benzoaz epin-1-yl) carbonyl]-2-phenylbenzanilide were synthesized and evaluated for arginine vasopressin (AVP) antagonistic activity. Compounds with a (Z)-olefin geometry at the 5-position of benzoazepine possessed potent affinity for both the V1A and V2 receptors. Further study has shown that one of these derivatives, (Z)-4'-(?4,4-difluoro-5-[(4-dimethylaminopiperidino)carbonylmet hylene]-2,3,4,5-tetrahydro-1H-1-benzoazepin-1-yI?carbonyl)2- phenylbenzanilide monohydrochloride (29, YM-35471), exhibits exceptionally potent affinity for both of V1A and V2 receptors, even when administered orally. The synthesis and pharmacological properties of this compound are detailed in this paper.     

Synthesis and biological evaluation of thiophene derivatives as acetylcholinesterase inhibitors

A series of new thiophene derivatives has been synthesized using the Gewald protocol. The acetylcholinesterase inhibition activity was assayed according to Ellman's method using donepezil as reference. Some of the compounds were found to be more potent inhibitors than the reference. 2-(2-(4-(4-Methoxyphenyl)piperazin-1-yl)acetamido)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxamide (IIId) showed 60% inhibition, compared to only 40% inhibition by donepezil.     

Discovery of an orally-active nonsteroidal androgen receptor pure antagonist and the structure-activity relationships of its derivatives

The 3-(4-cyano-3-trifluoromethylphenyl)-5,5-dimethylthiohydantoin derivatives which have carboxy-terminal side chains were synthesized and their agonistic/antagonistic activities against androgen receptor (AR) measured. Among them, compound 13b showed antagonistic activity (IC50=130 nM) with no agonistic activity even at 10000 nM. This compound exhibited significant metabolic stability and oral antiandrogenic activity (ED50=7 mg/kg).     

Synthesis and biological activities of 4-phenyl-5-pyridyl-1,3-thiazole derivatives as selective adenosine A3 antagonists

To investigate the potency of an adenosine A3 receptor (A3AR) antagonist as an anti-asthmatic drug, a novel series of 4-phenyl-5-pyridyl-1,3-thiazole derivatives was synthesized and evaluated in human adenosine A1, A2A and A3 receptor and rat adenosine A3 receptor binding assays. From investigation of the SAR study, compound 7af was identified as a highly potent human and rat A3AR antagonist. This compound inhibited IB-MECA-induced plasma protein extravasation in the skin of rats and showed good oral absorption. Also, compound 7af significantly inhibited antigen-induced hyper-responsiveness to acetylcholine in actively sensitized Brown Norway rats. These results show that 4-phenyl-5-pyridyl-1,3-thiazole derivatives are potential candidates to enable the evaluation of A3AR antagonists. Further evaluation of this class of compounds may afford a novel anti-inflammatory agent such as an anti-asthmatic drug.     

Synthesis and structure-activity relationships in a series of ethenesulfonamide derivatives, a novel class of endothelin receptor antagonists.

In the previous paper, we described a series of the 2-arylethenesulfonamide derivatives, a novel class of ETA-selective endothelin (ET) receptor antagonists, including the compounds 1a, b. Compound 1a showed excellent oral antagonistic activities and pharmacokinetic profiles, and the monopotassium salt of 1 (YM-598 monopotassium) is in clinical trials. In this paper, we wish to report the investigation of the further details of structure-activity relationships (SARs) of the 2-phenylethenesulfonamide region in 1a. It was found that methyl substitutions at the 2-, 4- and 6-positions of the phenyl group in 1a led to the discovery of the ET(A)/ET(B) mixed antagonist (6s) with an IC50 of 2.2 nM for the ET(A) receptor. We also found that introduction of an ethyl group to the 1-position of the ethenyl group in 1a gave the ET(A) selective antagonist (6u) with an oral endothelin antagonistic activity in rats.     

A novel class of inhibitors for human steroid 5 alpha-reductase: phenoxybenzoic acid derivatives. I.

In a search for novel nonsteroidal inhibitors of human prostatic 5 alpha-reductase, we found a new series of phenoxybenzoic acid derivatives to be potent human prostatic 5 alpha-reductase inhibitors. Among them, 4-(biphenyl-4-yloxy)benzoic acid derivatives (2n, YM-31758), 2o and 2s showed more potent inhibitory activities than finasteride with IC50 values of 0.87, 0.67 and 0.56 nM, respectively. The optimized structures for the phenoxybenzoic acid derivatives 2d-2i were calculated by molecular modeling analysis, and the favorable distance between the carbon of the carboxyl group and the centroid of the phenyl group (benzene ring C) was found to be in the 9-11 A range.     

Synthesis and biological activity of N-(aminoiminomethyl)-1H-indole carboxamide derivatives as Na+/H+ exchanger inhibitors

A series of N-(aminoiminomethyl)-1H-indole carboxamide derivatives were synthesized and their inhibitory potencies against the Na+/H+ exchanger were measured. Variation of the carbonylguanidine group at the 2- to 7-position of the indole ring system showed that a substitution at the 2-position improved the Na+/H+ exchanger inhibitory activity the most in vitro. This led to the synthesis and evaluation of an extensive series of N-(aminoiminomethyl)-1H-indole-2-carboxamide derivatives. Derivatives having an alkyl or substituted alkyl group at the 1-position of the indole ring system showed higher levels of in vitro activities. N-(aminoiminomethyl)- 1-(2-phenylethyl)-1H-indole-2-carboxamide (49) had the strongest activity.     

Synthesis and evaluation of N-phenyl-(2-aminothiazol-4-yl)acetamides with phenoxypropanolamine moiety as selective β3-adrenergic receptor agonists

In the search for potent and selective human β3-adrenergic receptor (AR) agonists as potential drugs for use in treating obesity and non-insulin dependent (type 2) diabetes, a series of N-phenyl-(2-aminothiazol-4-yl)acetamides with phenoxypropanolamine moiety were prepared and their biological activities against human β3-, β2-, and β1-ARs were evaluated. Among these compounds, N-phenyl-(2-phenylaminothiazol-4-yl)acetamide (4 g), N-phenyl-(2-benzylaminothiazol-4-yl)acetamide (4j), and N-phenyl-[2-(3-methoxyphenyl)aminothiazol-4-yl]acetamide (6g) derivatives showed potent agonistic activity against the β3-AR with functional selectivity over the β1- and β2-ARs. In addition, these compounds exhibited significant hypoglycemic activity in a rodent model of diabetes.     

Design,synthesis and insecticidal activities of novel 1-substituted-5-(trifluoromethyl)-1H-pyrazole-4-carboxamide derivatives

A series of novel 5-(trifluoromethyl)-1H-pyrazole-4-carboxamide derivatives(6a–6n, 7a, 7b, and 8a-8f)were synthesised by placing the amide bond at the 4-position of the pyrazole ring. These derivatives differed from the structure of chlorantraniliprole analogues with the amide bond at the 5-position of the pyrazole ring. Preliminary bioassay results revealed that a few title compounds exhibited good insecticidal activities against lepidopteran pests, such as Plutella xylostella, Mythimna separate, Heliothis armigera, and Ostrinia nubilalis. Some title compounds also elicited broad-spectrum insecticidal activities against dipterous insects including Culex pipiens pallens after altering the amide position. Similar to pyrazole-5-carboxamide analogues, compounds 6b and 6e showed 100% insecticidal activity against P. xylostella, C. pipiens pallens, and M. separate at concentrations of 200, 2, and 200 mg/m L, respectively.This finding suggested that 5-(trifluoromethyl)-1H-pyrazole-4-carboxamide derivatives are potential alternative insecticides for management of agriculture pests.     

Nonpeptide arginine vasopressin antagonists for both V1A and V2 receptors: synthesis and pharmacological properties of 4-(1,4,5,6-tetrahydroimidazo[4,5-d][1]benzoazepine-6-carbonyl)benzanili de derivatives and 4'-(5,6-dihydro-4H-thiazolo[5,4-d][1]benzoazepine-6-carbonyl)benzanilid e derivatives

Arginine vasopressin (AVP) has a dual action mainly in the periphery, i.e., vasoconstriction and water reabsorption via V1A and V2 receptors; it may play a role in a number of diseases, including congestive heart failure (CHF), hypertension, renal disease, edema, and hyponatremia. We have attempted to develop a new series of orally active AVP antagonists for both V1A and V2 receptors based on the hypothesis that the blockade of both V1A and V2 receptors might be beneficial to CHF patients. In this report, a series of compounds structurally related to 4'-(1,4,5,6-tetrahydroimidazo[4,5-d][1]benzoazepine-6- carbonyl)benzanilide and 4'-(5,6-dihydro-4H- thiazolo[5,4-d][1]benzoazepine-6-carbonyl)benzanilide were synthesized and examined for AVP antagonist activity for both V1A and V2 receptors. As a result, it was found that the 4'-(1,4,5,6-tetrahydroimidazo[4,5-d][1]benzoazepine-6-carbon yl)-2- phenylbenzanilide derivatives showed potent binding affinity for both V1A and V2 receptors. Especially, 4'-(2-methyl-1,4,5,6- tetrahydroimidazo[4,5-d][1]benzoazepine-6-carbonyl)-2-phe nylbenzanilide monohydrochloride (18, YM087 = conivaptan hydrochloride) exhibited potent binding affinity and AVP antagonist activity, after intravenous administration, for both V1A and V2 receptors. Furthermore, YM087 exhibited the most potent oral activity for the V2 receptor. Details of the synthesis and pharmacological properties of this series are presented.     

Preparation of highly potent and selective non-peptide antagonists of the arginine vasopressin V1A receptor by introduction of a 2-ethyl-1H-1-imidazolyl group

To find a new series of arginine vasopressin (AVP) V1A receptor antagonists, the influence of the 2-phenyl group of 2-phenyl-4'-[(2,3,4,5-tetrahydro-1H-1-benzazepin-1-yl)carbonyl]benzanilide (7) was investigated. Replacement of the 2-phenyl group by a 2-ethyl-1H-imidazol-1-yl group was effective in yielding a V1A-selective compound. Moreover, this imidazolyl group was introduced in the same position in YM-35471 (6), and further studies of these compounds were performed. Consequently, we found that the (Z)-4'-({4,4-difluoro-5-[(N-cyclopropylcarbamoyl)methylene]-2,3,4,5-tetrahydro-1H-1-benzazepin-1-yl}carbonyl)-2-(2-ethyl-1H-1-imidazol-1-yl)benzanilide (9f) exhibited highly potent affinity and selectivity, and was the most potent antagonist for the V1A receptor among our compounds. The synthesis and pharmacological evaluation of these compounds are described in this paper.     

Synthesis and Biological Activity Evaluation of Coumarin-3-Carboxamide Derivatives

A series of novel coumarin-3-carboxamide derivatives were designed and synthesized to evaluate their biological activities. The compounds showed little to no activity against gram-positive and gram-negative bacteria but specifically showed potential to inhibit the growth of cancer cells. In particular, among the tested compounds, 4-fluoro and 2,5-difluoro benzamide derivatives (14b and 14e, respectively) were found to be the most potent derivatives against HepG2 cancer cell lines (IC₅₀ = 2.62–4.85 μM) and HeLa cancer cell lines (IC₅₀ = 0.39–0.75 μM). The activities of these two compounds were comparable to that of the positive control doxorubicin; especially, 4-flurobenzamide derivative (14b) exhibited low cytotoxic activity against LLC-MK2 normal cell lines, with IC₅₀ more than 100 μM. The molecular docking study of the synthesized compounds revealed the binding to the active site of the CK2 enzyme, indicating that the presence of the benzamide functionality is an important feature for anticancer activity.     

Structure-activity relationships of 1,3-benzoxazole-4-carbonitriles as novel antifungal agents with potent in vivo efficacy

A series of 1,3-benzoxazole-4-carbonitriles was synthesized and evaluated for its antifungal activity, solubility, and metabolic stability. Among those compounds, 4-cyano-N,N,5-trimethyl-7-[(3S)-3-methyl-3-(methylamino)pyrrolidin-1-yl]-6-phenyl-1,3-benzoxazole-2-carboxamide (16b) exhibited potent in vitro activity against Candida species, higher water solubility, and improved metabolic stability compared to lead compound 1. Compound 16b showed potent in vivo efficacy against mice Candida infection models and good bioavailability in rats.     

Synthesis and pharmacology of 3,4-dihydro-3-oxo-1,4-benzoxazine-8-carboxamide derivatives, a new class of potent serotonin-3 (5-HT3) receptor antagonists.

A series of 3,4-dihydro-3-oxo-1,4-benzoxazine-8-carboxamide derivatives was synthesized and evaluated for serotonin-3 (5-HT3) receptor antagonistic activity assessed by their ability to antagonize the von Bezold-Jarish (BJ) effect in rats. Derivatives bearing 1-azabicyclo[2.2.2]oct-3-yl moiety as a basic function attached to the carboxamide at position 8 showed more potent antagonistic activity than those bearing the other three basic moieties. Structure-activity relationships of this series showed that methyl and chloro groups were more effective as substituents at positions 4 and 6, respectively. The representative compound 15 (Y-25130) in this series showed potent antagonistic activity on the BJ effect (ED50 = 1.3 micrograms/kg i.v.), high affinity for 5-HT3 receptor (Ki = 2.9 nM) and complete protection against cisplatin-induced emesis in dogs at a dose of 0.1 mg/kg i.v.