聚腺苷二磷酸核糖聚合酶-1抑制剂药效团模型的建立

建立聚腺苷二磷酸核糖聚合酶-1［poly(ADP-ribose)polymerase-1，PARP-1］抑制剂的药效团模型，探讨其与PARP-1的作用机制。利用Catalyst软件系统，选择具有较高体外抑制活性的8种结构类型的38个化合物作为训练集，经构象分析，分子叠合等过程构建出药效团模型。结合PARP-1的作用机制等因素，得到一个含有两个氢键接受体和两个芳香疏水性基团的PARP-1抑制剂药效团模型。本文建立的药效团模型的可靠性较高(RMS=0.46，Correl=0.91，Weight=2.06，Config=15.97)，不但给出了作用位点的相关信息，而且具有良好的活性预测能力，有助于新型结构的PARP-1抑制剂的设计。     

作用于秋水仙碱结合位点的微管蛋白抑制剂药效团的构建

目的:构建作用于秋水仙碱结合位点的微管蛋白抑制剂药效团模型;初步分析该类抑制剂与靶点的作用方式。方法:使用Discovery Studio软件中的HypoGen模块对训练集进行药效团模型的构建。结果:最佳药效团模型的线性回归相关系数最高(0.981),包含1个氢键给体和4个疏水中心,利用测试集验证了该药效团模型的活性预测能力;通过分子与活性位点的对接得到了活性最好的两个化合物与此结合位点的具体作用方式。结论:得到的药效团模型具有较好的预测能力,有利于设计和开发新型微管蛋白抑制剂。     

L-型钙离子通道抑制剂药效团模型的构建

目的构建L-型钙离子通道抑制剂的药效团模型,为从中药化学成分中发现具有钙离子通道抑制作用的成分提供了新的方法,同时为先导物改造成为活性较好的钙离子通道抑制剂提供思路。方法以来源于NCBI数据库中对新西兰兔心脏L-型钙离子通道具有抑制作用的12个化合物为研究对象,利用HipHop定性药效团模型构建方法,建立L-型钙离子通道拮抗剂的药效团模型,利用数据库搜索方法对药效团模型进行优劣评价。结果获得最优药效团模型具有以下几个特征:2个氢键受体和4个疏水基团,其综合评价指数CAI为2.78。结论构建的定性药效团具有一定的可靠性,可用于开展活性化合物筛选和指导先导化合物的结构改造,有助于指导发现中药中的L-型钙离子通道阻滞剂。     

小分子PB2蛋白抑制剂的虚拟筛选及初步活性研究

目的 通过药效团模型和分子对接筛选具有新型骨架的PB2蛋白抑制剂,并初步研究其活性.方法 利用HipHop程序建立PB2蛋白抑制剂的药效团模型,并利用该模型筛选Chemdiv数据库;对匹配较好的化合物利用CDOCKER进行筛选排序,挑选排序靠前的6个化合物,通过差示扫描量热法和Biacore体外活性测试方法进行生物活性...     

基于网络药理学、定量构效关系、分子对接探讨甘草黄酮抗痤疮的分子机制

目的 基于网络药理学、定量构效关系、分子对接探讨甘草黄酮抗痤疮可能的分子机制，为该成分透皮制剂的开发提供依据。方法 通过网络药理学筛选出甘草黄酮抗痤疮的关键活性成分与靶点，然后通过HipHop方法构建了甘草黄酮化合物活性的最佳QSAR药效团模型，并推测出该药效团可能起决定性治疗作用的药效基团，最后通过分子对接对该药效基团进行验证。结果 网络药理学研究表明7-羟基黄酮、甘草内酯、9S,13R-12-oxophytodienoic acid、柚皮素、4’-甲氧基黄酮等化合物是甘草黄酮中抗痤疮的关键活性成分，CYP19A1、ALOX5和ESR1是其抗痤疮的关键靶点。QSAR药效团模型研究表明，甘草黄酮的最优药效团由1个疏水基团，2个氢键受体基团组成。分子对接研究表明，通过网络药理学筛选的活性化合物和靶蛋白具有较好的亲和力，同时也发现通过QSAR构建的最优药效团模型可能是甘草黄酮抗痤疮中起决定性治疗作用的药效基团。结论 本研究成功建立了甘草黄酮的结构特性与其抗痤疮活性之间的构效关系，为中药透皮制剂的开发和临床应用提供了理论指导。     

采用药效团模型和分子对接方法筛选新型的组蛋白甲基转移酶G9a抑制剂

目的利用药效团模型和分子对接方法对商业化合物库ChemDiv中的G9afocused-libraries进行筛选,希望发现新骨架结构的G9a抑制剂。方法首先,使用Discovery studio 3.1软件分别构建基于配体的药效团模型和基于配体-受体复合物的药效团模型,并根据构建的2个模型再重新定义2个新的药效团模型。然后,构建测试集并测试药效团模型的预测能力。最后,选取最优药效团模型对G9afocused-libraries进行筛选,对筛选出的化合物使用CDOCKER分子对接进行分析与评价。结果测试结果显示,所构建的药效团模型具有一定的预测能力,通过该药效团筛选得到了2个结构新颖的潜在的G9a抑制剂。结论所构建的药效团模型具有一定的可靠性,虚拟筛选发现的G9a抑制剂还需进一步的实验证明。     

甲状旁腺素受体激动剂3D药效团模型的构建与应用

甲状旁腺素能增加人体骨密度和骨强度,是治疗骨质疏松症最有效的多肽类药物之一,但至今缺乏具有相应功能的小分子药物。根据计算机辅助药物设计原理,采用Discovery Studio 2.5软件包,以14个甲状旁腺素(PTH)受体激动剂及其突变类似物为训练集,利用活性构象限制的方法,采用HypoGen算法构建出具有活性预测功能的3D药效团模型。其中最好的药效团模型含有1个阳离子基团(PI),3个疏水中心(H)和1个氢键供体(HBD)。同时应用该模型成功预测出16个测试集分子的活性,经交叉验证表明该模型达到95%的置信水平,具有良好的活性预测能力。该药效团可以用于后续抗骨质疏松症小分子药物的筛选,指导相应的药物优化,同时所采用的限制构象的药效团生产方法为基于多肽的药物设计提供了一个新的思路。     

设定5—羟色胺能5—HT2a受体模型

不同化学结构类别的５－ＨＴ２ａ拮抗剂和激动剂，能符合一般药效基团模型。利用所研究药效基因模型设定片段氨基酸模型可反映结构的键合性质和亲和度，被推荐片段模型叠合在５－ＨＴ２ａ拮抗剂和激动剂，能符合一般药效基团模型。利用所研究药效基团模型设定片段氨基酸模型可反映结构的键合性质和亲和度，被推荐片段模型叠合在５－ＨＴ２ａ受体的透膜部位。研究是以结构明确的细菌紫质螺旋配体为模型，设计高亲和性５－ＨＴ２ａ的新     

基于Hypogen药效团模型发现潜在的PTP1B抑制剂

目的 采用计算机辅助药物设计的方法发现潜在的PTP1B抑制剂。方法 应用3D-QSAR药效团模型中的Hypogen模块构建药效团模型，成本分析、测试集预测和Fisher检验3种方法来验证该模型可用于预测化合物的生物活性的能力。运用该药效团模型对ZINC数据库进行虚拟筛选，得到Fit value值较高的先导化合物ZINC35671983。根据药效团的特征对ZINC35671983进行结构改造得到相应化合物。将化合物用ADMET进行成药预测。结果 ZINC35671983进行结构改造筛选获得92个化合物，筛出对接得分高于ZINC3567198的8个化合物。结论 发现8个潜在的PTP1B抑制剂，这有助于发现新的PTP1B先导化合物。     

对药远志-天麻中GABA-AT靶点抑制活性物质的虚拟筛选

目的 对对药远志-天麻中潜在作用于GABA转氨酶(GABA aminotransferase, GABA-AT)靶点的抗癫痫活性物质进行研究,阐明其药效物质基础。方法 收集文献中具有抑制GABA-AT活性的化合物信息,建立基于GABA-AT配体的HipHop药效团模型,收集文献中远志与天麻中的成分并建立化合物库,对远志与天麻中的成分与药效团进行匹配,采用柔性对接手段对匹配到的小分子化合物与GABA-AT靶点(PDB ID:1OHW)进行对接并评估其相互作用,采用体外酶活力法初步评价筛选到单体的GABA-AT的抑制活性。结果 通过文献检索共得到远志与天麻中化学成分26种,通过测试集验证选出优选药效团3用于对远志与天麻化合物库的虚拟筛选,匹配后得到10种远志与天麻中潜在的GABA-AT抑制成分。通过分子模拟对接分析了10种化合物对GABA-AT的作用情况,对其中4种单体进行了酶活力抑制能力评估。结论 基于药效团及分子模拟对接手段探讨远志与天麻中GABA-AT抑制成分具有一定的准确性。     

基于报告基因检测的β3肾上腺素受体激动剂筛选模型的建立与应用

目的：建立基于双荧光素酶报告基因检测的β3肾上腺素受体（β3-AR）激动剂筛选模型,并用于β3-AR激动剂的筛选。方法：应用免疫细胞化学法鉴定β3-AR在β3-CHO细胞上的稳定表达,并将pCRE-luc质粒与pRL-TK质粒共同瞬时转染β3-CHO细胞,建立一种基于双荧光素酶报告基因检测的β3-AR激动剂筛选模型。通过检测报告基因萤火虫荧光素酶与海肾荧光素酶活性的比值,来间接反映配体对β3-AR的激动活性。并以β-AR激动剂异丙肾上腺素刺激对模型的有效性进行验证,在此基础上以此模型对20种新化合物的β3-AR激动活性进行筛选。结果：β3-CHO细胞经免疫细胞化学法鉴定有特异性受体蛋白表达。通过将两个报告基因质粒转染该细胞后,与加入溶剂对照相比,加入异丙肾上腺素可显著促进荧光素酶报告基因的表达,表明该模型有效、可靠。以此模型从20个化合物中初筛出8个活性较强的β3-AR激动剂。结论：本研究建立了基于双荧光素酶报告基因检测的β3-AR激动剂筛选模型,并以此模型筛选发现了几个活性较强的β3-AR激动剂。     

GABA受体激动剂对氧-葡萄糖剥夺诱导皮层神经元死亡的保护作用

目的:研究GABA受体激动剂对氧-葡萄糖剥夺诱导皮层神经元死亡的保护作用。方法:培养12d的皮层神经元更换为Earle's平衡盐溶液(Earle's balanced salts,EBSS)后置于37℃三气缺氧(N2:CO2:O2=94%:5%:1%)培养箱内培养,4h后恢复正常条件培养,同时在培养液内加入GABA A受体和B受体激动剂作用24h,用Hoechst33342/PI的染色方法检测其死亡情况。结果:GABA A受体激动剂(musci mol)和GABA B受体激动剂(baclofen)均分别能显著降低神经细胞死亡率49.9%和35.3%。结论:GA-BA A受体激动剂和B受体激动剂对氧-葡萄糖剥夺诱导的皮层神经元死亡均有显著的保护作用。     

Synthesis and biological characterization of 1-methyl-1,2,5,6-tetrahydropyridyl-1,2,5-thiadiazole derivatives as muscarinic agonists for the treatment of neurological disorders

Muscarinic agonists might be useful in the treatment of neurological disorders, including Alzheimer's disease, schizophrenia, chronic pain, and drug abuse. Previous studies identified a series of bis-1,2,5-thiadiazole derivatives of 1,2,5,6-tetrahydropyridine with high activity and selectivity for muscarinic receptors. To develop compounds with improved central nervous system penetration, several new derivatives were synthesized and characterized for muscarinic receptor binding and activity. One ligand (11) exhibited agonist activity at M(1), M(2), and M(4) receptors, a selectivity profile suggesting potential utility in the treatment of schizophrenia.     

Functional comparison of muscarinic partial agonists at muscarinic receptor subtypes hM1, hM2, hM3, hM4 and hM5 using microphysiometry.

1. This study describes the pharmacological comparison of the muscarinic partial agonists sabcomeline, xanomeline and milameline at human cloned muscarinic receptor subtypes (hM1-5). 2. Radioligand binding studies at the hM1-5 muscarinic receptor subtypes were compared with functional studies using microphysiometry using carbachol as the standard full agonist. 3. In binding assays none of the compounds studied displayed preferential affinity for the M1,3,4 or M5 subtypes although carbachol was less potent at hM1 than hM3,4,5. 4. In functional studies, all of the compounds studied displayed similar levels of efficacy across the muscarinic receptors with the exception of M3, where there was a large apparent receptor reserve and the compounds behaved essentially as full agonists. 5. Sabcomeline was the most potent agonist in functional studies but also showed the lowest efficacy. In terms of potency, xanomeline showed some selectivity for M1 over M2 receptors and milameline showed some selectivity for M2 over M1 receptors. 6. These results show the value of microphysiometry in being able to compare receptor pharmacology across subtypes irrespective of the signal transduction pathway. 7. None of the partial agonists showed functional selectivity for M1 receptors, or indeed any muscarinic receptor, in the present study.     

新型免疫抑制剂鞘氨醇-1-磷酸受体激动剂研究进展

免疫抑制剂在器官移植和自身免疫系统疾病的治疗方面疗效显著,但多种不良反应限制了其广泛应用。在寻找高活性、低不良反应的新型免疫抑制剂的过程中发现,鞘氨醇-1-磷酸（S1P）受体激动剂通过使淋巴细胞聚集在淋巴结、脾等次级淋巴器官中,导致血液和胸腺的淋巴细胞减少,同时抑制淋巴细胞进入移植器官中,减少移植排斥反应。因此,通过激动S1P受体阻断淋巴细胞循环可以用于治疗免疫系统疾病。本文主要综述新型免疫抑制剂S1P受体全激动剂和选择性激动剂的特点、作用机制及研究进展。     

Estimation of relative microscopic affinity constants of agonists for the active state of the receptor in functional studies on M2 and M3 muscarinic receptors

In prior work, we have shown that it is possible to estimate the product of observed affinity and intrinsic efficacy of an agonist expressed relative to that of a standard agonist simply through the analysis of their respective concentration-response curves. In this report, we show analytically and through mathematical modeling that this product, termed intrinsic relative activity (RA(i)), is equivalent to the ratio of microscopic affinity constants of the agonists for the active state of the receptor. We also compared the RA(i) estimates of selected muscarinic agonists with a relative estimate of the product of observed affinity and intrinsic efficacy determined independently through the method of partial receptor inactivation. There was good agreement between these two estimates when agonist-mediated inhibition of forskolin-stimulated cAMP accumulation was measured in Chinese hamster ovary cells stably expressing the human M(2) muscarinic receptor. Likewise, there was good agreement between the two estimates when agonist activity was measured on the ileum from M(2) muscarinic receptor knockout mice, a convenient assay for M(3) receptor activity. The RA(i) estimates of agonists in the mouse ileum were similar to those estimated at the human M(3) receptor with the exception of 4-(m-chlorophenyl-carbamoyloxy)-2-butynyltrimethylammonium (McN-A-343), which is known to be an M(1)- and M(4)-selective muscarinic agonist. Additional experiments showed that the response to McN-A-343 in the mouse ileum included a non-M(3) muscarinic receptor component. Our results show that the RA(i) estimate is a useful receptor-dependent measure of agonist activity and ligand-directed signaling.     

Muscarinic subtype affinity and functional activity profile of 1-methyl-2-(2-methyl-1,3-dioxolan-4-yl)pyrrolidine and 1-methyl-2-(2-methyl-1,3-oxathiolan-5-yl)pyrrolidine derivatives

Starting from two previously studied muscarinic full agonists, characterized by a 1,3-dioxolane ((+)-1) and a 1,3-oxathiolane ((+)-2) cycle, two new series of muscarinic ligands were designed, obtained by the steric complication of the parent compounds produced by freezing the aminoalkyl chain into a pyrrolidine ring. Both tertiary amines and the corresponding iodomethyl derivatives were synthesised and studied, and several compounds of the series which behaved as muscarinic agonists have been selected, on the basis of preliminary binding experiments on rat cortex homogenates, for the present work. Results are presented obtained from testing the affinity of the selected compounds against cloned human muscarinic receptors expressed in CHO cells, in order to evaluate subtype selectivity. Their functional activity on classical models of M1-M4 receptors, in guinea pig and rabbit tissues is also reported. With respect to parent compounds, the new molecules present some selectivity toward hm2 receptors; fair M2 selectivity is also evident in functional studies, where these compounds behave as partial agonists. Among the other compounds of the series (2S, 4'R, 2'S)-1,1-dimethyl-2-(2-methyl-1,3-dioxolan-4-yl)pyrrolidinium iodide (-)-3 and (2R, 5'S, 2'S)-1-methyl-2-(2-methyl-1,3-oxathiolan-5-yl)pyrrolidine (+)-5 present a promising pharmacological profile. Compound (-)-3 shows modest hm2 selectivity in binding experiments but a clearcut M2 selectivity in functional tests, where it behaves as a weak antagonist on M1 and M4 subtypes, as a weak full agonist on the M3 subtype and as a potent partial agonist on M2 subtype. Tertiary amine (+)-5 presents a quite similar profile but appears more interesting since, lacking a permanent charge on the nitrogen atom, it may represent an interesting tool to study CNS muscarinic receptors. Our results confirm that sterical complication of parent compounds (+)-1 and (+)-2 produces more selective muscarinic agonists.     

Novel functional M1 selective muscarinic agonists. 2. Synthesis and structure-activity relationships of 3-pyrazinyl-1,2,5,6-tetrahydro-1-methylpyridines. Construction of a molecular model for the M1 pharmacophore.

A series of 3-(3-substituted-pyrazinyl)-1,2,5,6-tetrahydro-1-methylpyridines were synthesized and found to have high affinity for central muscarinic receptors. The ability of some of these compounds to inhibit the electrically stimulated twitch of the guinea pig vas deferens indicated that the compounds were M1 agonists. M1 agonist activity was related to the length of the side chain attached to the pyrazine ring, with maximal activity being obtained with the hexyloxy side chain. The (hexyloxy)pyrazine 3f lacked M2 agonist activity as it failed to affect the guinea pig atria and was also relatively devoid of M3 agonist activity as determined by its lack of tremorogenic and sialogogic effects in mice. A comparison of the M1 agonist efficacy of these pyrazines and related 1,2,5-thiadiazoles and 1,2,5-oxadiazoles suggested that M1 efficacy was related to the magnitude of electrostatic potential located over the nitrogens of the respective heterocycles. The heteroatom directly attached to the 3 position of the pyrazine or 1,2,5-thiadiazole heterocycle markedly influenced the M1 efficacy of the compounds by determining the energetically favorably conformers for rotation about the bond connecting the tetrahydropyridyl ring and the heterocycle. A three-dimensional model for the M1-activating pharmacophore was proposed based on computational studies and the model of the muscarinic pharmacophore proposed by Schulman.     

1-aryl-3-(4-pyridine-2-ylpiperazin-1-yl)propan-1-one oximes as potent dopamine D4 receptor agonists for the treatment of erectile dysfunction

A new series of dopamine D4 receptor agonists, 1-aryl-3-(4-pyridinepiperazin-1-yl)propanone oximes, was designed through the modification of known dopamine D4 receptor agonist PD 168077. Replacement of the amide group with a methylene-oxime moiety produced compounds with improved stability and efficacy. Structure-activity relationsips (SAR) of the aromatic ring linked to the N-4-piperazine ring confirmed the superiority of 2-pyridine as a core for D4 agonist activity. A two-methylene linker between the oxime group and the N-1-piperazine ring displayed the best profile. New dopamine D4 receptor agonists, exemplified by (E)-1-(4-chlorophenyl)-3-(4-pyridin-2-ylpiperazin-1-yl)propan-1-one O-methyloxime (59a) and (E)-1-(3-chloro-4-fluorophenyl)-3-(4-pyridin-2-ylpiperazin-1-yl)propan-1-one O-methyloxime (64a), exhibited favorable pharmacokinetic profiles and showed oral bioavailability in rat and dog. Subsequent evaluation of 59a in the rat penile erection model revealed in vivo activity, comparable in efficacy to apomorphine. Our results suggest that the oximes provide a novel structural linker for 4-arylpiperazine-based D4 agonists, possessing leadlike quality and with potential to develop a new class of potent and selective dopamine D4 receptor agonists.