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1.
A series of ring-substituted ethyl- and heptyl-linked 4-aminoquinoline dimers were synthesized and evaluated for their affinities at the 3 human α1-adrenoceptor (α1-AR) subtypes and the human serotonin 5-HT1A-receptor (5-HT1A-R). We find that the structure-specificity profiles are different for the two series at the α1-AR subtypes, which suggests that homobivalent 4-aminoquinolines can be developed with α1-AR subtype selectivity. The 8-methyl (8-Me) ethyl-linked analogue has the highest affinity for the α1A-AR, 7 nM, and the greatest capacity for discriminating between α1A-AR and α1B-AR (6-fold), α1D-AR (68-fold), and the 5-HT1A-R (168-fold). α1B-AR selectivity was observed with the 6-methyl (6-Me) derivative of the ethyl- and heptyl-linked 4-aminoquinoline dimers and the 7-methoxy (7-OMe) derivative of the heptyl-linked analogue. These substitutions result in 4- to 80-fold selectivity for α1B-AR over α1A-AR, α1D-AR, and 5-HT1A-R. In contrast, 4-aminoquinoline dimers with selectivity for α1D-AR are more elusive, since none studied to date has greater affinity for the α1D-AR over the other two α1-ARs. The selectivity of the 8-Me ethyl-linked 4-aminoquinoline dimer for the α1A-AR, and 6-Me ethyl-linked, and the 6-Me and 7-OMe heptyl-linked 4-aminoquinoline dimers for the α1B-AR, makes them promising leads for drug development of α1A-AR or α1B-AR subtype selective ligands with reduced 5-HT1A-R affinity.  相似文献   

2.
A series of arylsulfonamide derivatives of (aryloxy)ethyl pyrrolidines and piperidines was synthesized to develop new α1-adrenoceptor antagonists with uroselective profile. Biological evaluation for α1- and α2-adrenorecepor showed that tested compounds 1337 displayed high-to-moderate affinity for the α1-adrenoceptor (Ki = 34–348 nM) and moderate selectivity over α2-receptor subtype. Compounds with highest affinity and selectivity for α1-adrenoceptor were evaluated in vitro for their intrinsic activity toward α1A- and α1B-adrenoceptor subtypes. All compounds behaved as antagonists at both α1-adrenoceptor subtypes, displaying 2- to 6-fold functional preference to α1A-subtype. Among them, N-{1-[2-(2-methoxyphenoxy)ethyl]piperidin-4-yl}isoquinoline-4-sulfonamide (25) and 3-chloro-2-fluoro-N-{[1-(2-(2-isopropoxyphenoxy)ethyl)piperidin-4-yl]methyl}benzene sulfonamide (34) displayed the highest preference to α1A-adrenoceptor. Finally, compounds 25 and 34 (2–5 mg/kg, iv), in contrast to tamsulosin (1–2 mg/kg, iv), did not significantly decrease systolic and diastolic blood pressure in normotensive anesthetized rats to determine their influence on blood pressure.  相似文献   

3.
Starting from compounds previously identified as α1-adrenoceptor antagonists that were also found to bind to the 5-HT1A receptor, in an attempt to separate the two activities, a new series of 5-HT1A receptor agonists was identified and shown to have high potency and/or high selectivity. Of these, compound 13, which combines high selectivity (5-HT1A1 = 151) and good agonist potency (pD2 = 7.82; Emax = 76), was found to be the most interesting.  相似文献   

4.
To identify potent dual 5-HT2B and 5-HT7 receptor antagonists, we synthesized a series of novel carbonyl guanidine derivatives and examined their structure–activity relationships. Among these compounds, N-(9-hydroxy-9H-fluorene-2-carbonyl)guanidine (10) had a good in vitro profile, that is, potent affinity for human 5-HT2B and 5-HT7 receptor subtypes (Ki = 1.8 nM and Ki = 17.6 nM, respectively) and high selectivity over 5-HT2A, 5-HT2C, α1, D2 and M1 receptors. Compound 10 also showed a suppressing effect on 5-HT-induced dural protein extravasation in guinea pigs when orally administered.  相似文献   

5.
(+)-Cyclazosin [(+)-1] is one of most selective antagonists of the α1B-adrenoceptor subtype (selectivity ratios, α1B1A?=?13, α1B1D?=?38–39). To improve the selectivity, we synthesized and pharmacologically studied the blocking activity against α1-adrenoceptors of several homochiral analogues of (+)-cyclazosin featuring different substituents on the carbonyl or amine groups, namely (?)-2, (+)-3, (?)-4(?)-8, (+)-9. Moreover, we studied the activity of some their opposite enantiomers, namely (?)-1, (?)-3, (+)-6, and (?)-9, to evaluate the influence of stereochemistry on selectivity. The benzyloxycarbonyl and methyl (4aS,8aR) analogues (+)-3 and (?)-6 improved in a significant way the α1B selectivity of the progenitor compound: 4 and 14 time vs. the α1D subtype and 35 and 77 times vs. the α1A subtype, respectively. The study confirmed the importance of the hydrophobic cis-octahydroquinoxaline moiety of these molecules for the establishment of interactions with the α1-adrenoceptors as well that of their (4aS,8aR) stereochemistry to grant selectivity for the α1B subtype. Hypotheses on the mode of interaction of these compounds were advanced on the basis of molecular modeling studies performed on compound (+)-3.  相似文献   

6.
The synthesis and in vitro preclinical profile of a series of 5-heteroaryl substituted analogs of the antipsychotic drug sertindole are presented. Compounds 1-(4-fluorophenyl)-3-(1-methylpiperidin-4-yl)-5-(pyrimidin-5-yl)-1H-indole (Lu AA27122, 3i) and 1-(4-fluorophenyl)-5-(1-methyl-1H-1,2,4-triazol-3-yl)-3-(1-methylpiperidin-4-yl)-1H-indole (3l) were identified as high affinity α1A-adrenoceptor ligands with Ki values of 0.52 and 0.16 nM, respectively, and with a >100-fold selectivity versus dopamine D2 receptors. Compound 3i showed almost equal affinity for α1B- (Ki = 1.9 nM) and α1D-adrenoceptors (Ki = 2.5 nM) as for α1A, as well as moderate affinity for 5-HT1B (Ki = 13 nM) and 5-HT6 (Ki = 16 nM) receptors, whereas 3l showed >40-fold selectivity toward all other targets tested. Based on in vitro assays for assessment of permeability rates and extent, it is predicted that both compounds enter the brain of rats, non-human primates, as well as humans, and as such are good candidates to be carried forward for further evaluation as positron emission tomography (PET) ligands.  相似文献   

7.
A series of 9-disubstituted N-(9H-fluorene-2-carbonyl)guanidine derivatives have been discovered as potent and orally active dual 5-HT2B and 5-HT7 receptor antagonists. Upon screening several compounds, N-(diaminomethylene)-4′,5′-dihydro-3′H-spiro[fluorene-9,2′-furan]-2-carboxamide (17) exhibited potent affinity for both 5-HT2B (Ki = 5.1 nM) and 5-HT7 (Ki = 1.7 nM) receptors with high selectivity over 5-HT2A, 5-HT2C, α1, D2 and M1 receptors. Optical resolution of the intermediate carboxylic acid 16 via the formation of diastereomeric salts using chiral alkaloids gave the optically pure compounds (R)-17 and (S)-17. Both enantiomers suppressed 5-HT-induced dural protein extravasation in guinea pigs in a dose-dependent manner and the amount of leaked protein was suppressed to near normal levels when orally administrated at 10 mg/kg. (R)-17 and (S)-17 were therefore selected as candidates for human clinical trials.  相似文献   

8.
Exploration of multiple regions of a bi-aryl amine template led to the identification of highly potent M3 muscarinic acetylcholine receptor antagonists such as 14 (pA2 = 11.0) possessing good sub-type selectivity for M3 over M2. The structure–activity relationships (SAR) and optimization of the bi-aryl amine series are described.  相似文献   

9.
It has been shown that the sympathetic nervous system is activated in pulmonary arterial hypertension (PAH). Norepinephrine (NE) levels are increased by chemoreflex-dependent sympathetic overactivation and involved in pulmonary vascular remodeling. However, the underlying mechanisms of the remodeling induced by NE are poorly understood. In this study, we found that, in vivo, the expression of tyrosine hydroxylase and the concentration of plasma NE were increased in PAH rats compared with normal rats. Increases in ventricular hypertrophy and medial width of the pulmonary arteries were reversed by prazosin, α1-adrenoceptor (α1-AR) antagonists, in PAH rats. Elevated expression of α1D-AR was detected in PAH rats. In addition, prazosin reduced the increasing expression of PCNA, CyclinA and CyclinE induced by hypoxia. In vitro, MTT assay, flow cytometry, Western blotting and immunofluorescence were performed to investigate the effects of NE on proliferation of pulmonary artery smooth muscle cells (PASMCs). We revealed that NE promoted PASMCs viability, increased the expression of PCNA, CyclinA and CyclinE, made more cells from G0/G1 phase to G2/M + S phase and enhanced the microtubule formation. Above NE-induced changes could be suppressed by BMY 7378, an inhibitor of α1D-AR. Furthermore, ERK-1/2 pathway was activated by NE. U0126, a specific inhibitor for ERK-1/2, attenuated the NE-induced proliferation of PASMCs under normoxia and hypoxia. Taken together, our results suggest that NE which stimulates α1D-AR promotes proliferation of PASMCs and the effect is, at least in part, mediated via the ERK-1/2 pathway.  相似文献   

10.
The dopamine D4 receptor has been shown to play key roles in certain CNS pathologies including addiction to cigarette smoking. Thus, selective D4 ligands may be useful in treating some of these conditions. Previous studies in our laboratory have indicated that the piperazine analog of haloperidol exhibits selective and increased affinity to the DAD4 receptor subtype, in comparison to its piperidine analog. This led to further exploration of the piperazine moiety to identify new agents that are selective at the D4 receptor. Compound 27 (KiD4 = 0.84 nM) was the most potent of the compounds tested. However, it only had moderate selectivity for the D4 receptor. Compound 28 (KiD4 = 3.9 nM) while not as potent, was more discriminatory for the D4 receptor subtype. In fact, compound 28 has little or no binding affinity to any of the other four DA receptor subtypes. In addition, of the 23 CNS receptors evaluated, only two, 5HT1AR and 5HT2BR, have binding affinity constants better than 100 nM (Ki <100 nM). Compound 28 is a potentially useful D4-selective ligand for probing disease treatments involving the D4 receptor, such as assisting smoking cessation, reversing cognitive deficits in schizophrenia and treating erectile dysfunction. Thus, further optimization, functional characterization and evaluation in animal models may be warranted.  相似文献   

11.
The enantiomers of two analogs of Sazetidine-A as well as several other novel biosteric analogues were synthesized. Their binding affinities at three major nAChRs subtypes and selectivity profiles were determined. Though many (S)-enantiomers of Sazetidine-A analogs have high binding affinities and good subtype selectivities, it is not a general rule that (S)-enantiomers are better than their (R) counterparts. Compound 11, of which the ethynyl group was replaced by its’ bioisostere—the triazole via click chemistry, showed a high binding affinity to α4β2 subtype (Ki = 1.3 nM) and better selectivity to the α4β2 subtype over α3β4 subtype with that of Sazetidine-A. The azide compound 15, a potential photoaffinity label, showed improved high selectivity and similar binding property profile with that of Sazetidine-A. The biaryl analog 17 exhibited a much lower affinity as compared to Sazetidine-A indicating the importance of a ‘long tail’ side chain for α4β2 nAChR binding.  相似文献   

12.
A series of N-(2-methoxyphenyl)homopiperazine analogs was prepared and their affinities for dopamine D2, D3, and D4 receptors were measured using competitive radioligand binding assays. Several ligands exhibited high binding affinity and selectivity for the D3 dopamine receptor compared to the D2 receptor subtype. Compounds 11a, 11b, 11c, 11f, 11j and 11k had Ki values ranging from 0.7 to 3.9 nM for the D3 receptor with 30- to 170-fold selectivity for the D3 versus D2 receptor. Calculated log P values (log P = 2.6–3.6) are within the desired range for passive transport across the blood–brain barrier. When the binding and the intrinsic efficacy of these phenylhomopiperazines was compared to those of previously published phenylpiperazine analogues, it was found that (a) affinity at D2 and D3 dopamine receptors generally decreased, (b) the D3 receptor binding selectivity (D2:D3 Ki value ratio) decreased and, (c) the intrinsic efficacy, measured using a forskolin-dependent adenylyl cyclase inhibition assay, generally increased.  相似文献   

13.
Fenpropimorph (1) is considered a “super high-affinity” σ1 receptor ligand (Ki = 0.005 nM for guinea pig σ1 receptors). Here, we examine the binding of 1 and several of its deconstructed analogs at human σ1 (hσ1) receptors. We monitored their subtype selectivity by determining the binding affinity at σ2 receptors. In addition, we validated an existing pharmacophore model at the molecular level by conducting 3D molecular modeling studies, using the crystal structure of hσ1 receptors, and Hydrophatic INTeractions (HINT) analysis. Our structure affinity relationship studies showed that 1 binds with lower affinity at hσ1 receptors (Ki = 17.3 nM) compared to guinea pig; moreover, we found that none of the fenpropimorph methyl groups is important for its binding at hσ1 receptors, nor is stereochemistry. For example, removal of all methyl groups as seen in 4 resulted in an almost 5-fold higher affinity at hσ1 receptors compared to 1 and 350-fold selectivity versus σ2 receptors. In addition, although the O atom of the morpholine ring does not contribute to affinity at hσ1 receptors (and might even detract from it), it plays role in subtype (σ1 versus σ2 receptor) selectivity.  相似文献   

14.
α1-Adrenoceptor (α1-AR) antagonists are considered to be the most effective monotherapy agents for lower urinary tract symptoms associated with benign prostatic hyperplasia (LUTS/BPH). In this study, we synthesized compounds 217, which are novel piperazine derivatives that contain methyl phenylacetate. We then evaluated the vasodilatory activities of these compounds. Among them, we found that compounds 2, 7, 12, which contain 2-OCH3, 2-CH3 or 2, 5-CH3, respectively, exhibited potent α1-blocking activity similar to protype drug naftopidil (1). The antagonistic effects of 2, 7, and 12 on the (?)-noradrenaline-induced contractile response of isolated rat prostatic vas deferens (α1A), spleen (α1B) and thoracic aorta (α1D) were further characterized to assess the sub receptor selectivity. Compared with naftopidil (1) and terazosin, compound 12 showed the most desirable α1D/1A subtype selectivity, especially improved α1A subtype selectivity, and the ratios pA2 (α1D)/pA2 (α1B) and pA2 (α1A)/pA2 (α1B) were 17.0- and 19.5-fold, respectively, indicating less cardiovascular side effects when used to treat LUTS/BPH. Finally, we investigated the chiral pharmacology of 12. We found, however, that the activity of enantiomers (R)-12 and (S)-12 are not significantly different from that of rac-12.  相似文献   

15.
The aim of the present study was to determine drug-α1D adrenergic receptor (AR) affinity by frontal analysis of cell-membrane chromatography (CMC). The cell-membrane stationary phase (CMSP) was prepared by immobilizing rat aorta cell membranes on porous silica, and the resulting CMSP was used to determine drug binding affinity to α1D-AR by frontal analysis. The CMSP of rat aorta was stable and reproducible. Relative binding affinities (dissociation constant, Kd) were determined by frontal chromatography for prazosin (166.13 ± 18.36 nmol), BMY7378 (537.40 ± 30.84 nmol), phentolamine (646.92 ± 23.17 nmol), 5-methylurapidil (725.66 ± 25.48 nmol), oxymetazoline (910.56 ± 40.62 nmol) and methoxamine (1299.27 ± 51.73 nmol). These results were consistent with the affinity rank order and showed a good correlation with the affinity of the same compounds for the cloned α1D-AR subtype obtained from radioligand-binding assay. The study demonstrates that frontal analysis of CMC may be used for direct determination of drug–receptor binding interactions, and that CMC is an alternative reliable method to quantitatively study ligand–receptor interactions.  相似文献   

16.
We previously reported that the novel dual 5-HT2B and 5-HT7 receptor antagonist N-(9-hydroxy-9H-fluorene-2-carbonyl)guanidine (4) exerted a suppressing effect on 5-HT-induced dural protein extravasation in guinea pigs. To develop a synthetic strategy, we performed docking studies of lead compound 4 bound to 5-HT2B and 5-HT7 receptors, and observed that the carbonyl guanidine group forms a tight interaction network with an active center Asp (D135:5-HT2B, D162:5-HT7), Tyr (Y370:5-HT2B, Y374:5-HT7) and aromatic residue (W131:5-HT2B, F158:5-HT7). Based on molecular modeling results, we optimized the substituents at the 5- to 8-position and 9-position of the fluorene ring and identified N-(diaminomethylene)-9-hydroxy-9-methyl-9H-fluorene-2-carboxamide (24a) exhibits potent affinity for 5-HT2B (Ki = 4.3 nM) and 5-HT7 receptor (Ki = 4.3 nM) with high selectivity over 5-HT2A, 5-HT2C, α1, D2 and M1 receptors. Compound 24a reversed the hypothermic effect of 5-carboxamidotryptamine (5-CT) in mice and also showed a suppressing effect on 5-HT-induced dural protein extravasation in guinea pigs when orally administered at 30 mg/kg. Compound 24a is therefore a promising candidate for a novel class of anti-migraine agent without any adverse effects.  相似文献   

17.
A series of novel 3-substituted-indole derivatives with a benzyl tertiary amino moiety were designed, synthesized and evaluated as H3 receptor antagonists and free radical scavengers for Alzheimer’s disease therapy. Most of these synthesized compounds exhibited moderate to potent antagonistic activities in CREs driven luciferase assay. In particular, compound 2d demonstrated the most favorable H3 receptor antagonistic activity with the IC50 value of 0.049 μM. Besides, it also displayed high binding affinity to H3 receptor (Ki = 4.26 ± 2.55 nM) and high selectivity over other three histamine receptors. Moreover, 2d and other two 3-substituted indole derivatives 1d and 3d exerted potent ABTS radical cation scavenging capacities similar to melatonin. Above results illustrate that 2d is an interesting lead for extensive optimization to explore new drug candidate for AD therapy.  相似文献   

18.
A number of 1,3-dialkyl-9-deazaxanthines (9-dAXs), bearing a variety of N-substituted benzyloxycarbonylamino substituents at position 8, were prepared and evaluated for their binding affinity to the recombinant human adenosine receptors (hARs), chiefly to the hA2B and hA2A AR subtypes. Several ligands endowed with excellent binding affinity to the hA2B receptors, but low selectivity versus hA2A and hA1 were identified. Among these, 1,3-dimethyl-N-3′-thienyl carbamate 15 resulted as the most potent ligand at hA2B (Ki = 0.8 nM), with a low selectivity versus hA2A (hA2A/hA2B = 12.6) and hA1 (hA1/hA2B = 12.5) and a higher selectivity versus hA3 (hA3/hA2B = 454). When tested in functional assays in vitro, compound 15 exhibited high antagonist activities and efficacies versus both the A2A and A2B receptor subtypes, with pA2 values close to the corresponding pKis. A comparative analysis of structure–affinity and structure–selectivity relationships of the similar analogues 8-N-substituted benzyloxycarbonylamino- and 8-N-substituted phenoxyacetamido-9-dAXs suggested that their binding modes at the hA2B and hA2A ARs may strongly differ. Computational studies help to clarify this striking difference arising from a simple, albeit crucial, structural change, from CH2OCON to OCH2CON, in the para-position of the 8-phenyl ring.  相似文献   

19.
20.
(Piperazin-1-yl-phenyl)-arylsulfonamides were synthesized and identified to show high affinities for both 5-HT2C and 5-HT6 receptors. Among them, naphthalene-2-sulfonic acid isopropyl-[3-(4-methyl-piperazin-1-yl)-phenyl]-amide (6b) exhibits the highest affinity towards both 5-HT2C (IC50 = 4 nM) and 5-HT6 receptors (IC50 = 3 nM) with good selectivity over other serotonin (5-HT1A, 5-HT2A, and 5-HT7) and dopamine (D2–D4) receptor subtypes. In 5-HT2C and 5-HT6 receptor functional assays, this compound showed considerable antagonistic activity for both receptors.  相似文献   

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