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1.
摘要 目的:构建环氧合酶-2(Cyclooxygenase-2,COX-2)抑制剂分类模型,用以筛选和优化COX-2抑制剂。方法:基于八种机器学习算法构建模型,比较不同模型的预测性能,筛选出最优模型后利用Y随机验证法对其进行测试,最后运用SHAP(Shapley Additive eXplanation)算法对最优模型进行可解释性分析。结果:八种不同模型的性能比较结果显示,基于随机森林算法建立的模型最优,其预测准确率、平衡准确率、马修斯相关系数、特征曲线下面积和F1分数(分别为0.893、0.825、0.673、0.909和0.933)最高;Y随机验证结果表明最优模型的预测结果并非偶然;此外,通过SHAP算法挖掘出20个最有可能影响COX-2抑制剂活性的结构片段。结论:本研究为新型COX-2抑制剂的开发提供理论依据,可供本领域其他研究人员对先导化合物进行优化或设计更好的COX-2抑制剂。  相似文献   

2.
探索黄酮类化合物抗环氧合酶-2的分子机理,筛选鸡血藤中选择性抗环氧合酶-2的黄酮类化合物。本研究应用Autodock 4.2软件对环氧合酶和环氧合酶抑制剂进行分子对接研究,建立阳性抑制剂结合自由能与抑制活性关系模型,并筛选鸡血藤中选择性抗环氧合酶-2的黄酮类化合物。阳性抑制剂与环氧合酶的对接模型R2分别为0.96997和0.84171,建立了预测能力较好的对接模型,可用于指导环氧合酶抑制剂的筛选。筛选结果表明,3',4',7-三羟基黄酮、儿茶素、没食子儿茶素、表儿茶素具有较强的环氧合酶-2选择性抑制活性,可作为母体用于新型抗炎药物设计。  相似文献   

3.
探索黄酮类化合物抗环氧合酶-2的分子机理,筛选鸡血藤中选择性抗环氧合酶-2的黄酮类化合物。本研究应用Autodock 4.2软件对环氧合酶和环氧合酶抑制剂进行分子对接研究,建立阳性抑制剂结合自由能与抑制活性关系模型,并筛选鸡血藤中选择性抗环氧合酶-2的黄酮类化合物。阳性抑制剂与环氧合酶的对接模型R2分别为0.96997和0.84171,建立了预测能力较好的对接模型,可用于指导环氧合酶抑制剂的筛选。筛选结果表明,3',4',7-三羟基黄酮、儿茶素、没食子儿茶素、表儿茶素具有较强的环氧合酶-2选择性抑制活性,可作为母体用于新型抗炎药物设计。  相似文献   

4.
为研究COX-2与中药抗肿瘤多药耐药的相关性,通过体外酶反应筛选实验,测定姜黄素、青藤碱、牡荆素、芹菜素对环氧合酶-1(COX-1)、环氧合酶-2(COX-2)的活性抑制作用,使用选择性指数(COX-1的IC50/COX-2的IC50)评价其COX-2活性的选择性,该实验结果显示:这四种物质对COX-2选择性指数依次为:牡荆素128. 71、姜黄素16. 24、芹菜素8. 45、青藤碱3. 55。并首次用分子对接相关数据中对接分子的对接内能及其与分子酶结合能差异性大小比较,评价了这四种物质对COX-2选择性活性,所得分子选择性结果与体外酶反应实验结果相吻合。从抑制活性和对COX-2选择性指数综合评价,牡荆素为较优化合物,可作为新的对COX-2有更高选择性活性的先导化合物。  相似文献   

5.
为研究COX-2与中药抗肿瘤多药耐药的相关性,通过体外酶反应筛选实验,测定姜黄素、青藤碱、牡荆素、芹菜素对环氧合酶-1(COX-1)、环氧合酶-2(COX-2)的活性抑制作用,使用选择性指数(COX-1的IC50/COX-2的IC50)评价其COX-2活性的选择性,该实验结果显示:这四种物质对COX-2选择性指数依次为:牡荆素128. 71、姜黄素16. 24、芹菜素8. 45、青藤碱3. 55。并首次用分子对接相关数据中对接分子的对接内能及其与分子酶结合能差异性大小比较,评价了这四种物质对COX-2选择性活性,所得分子选择性结果与体外酶反应实验结果相吻合。从抑制活性和对COX-2选择性指数综合评价,牡荆素为较优化合物,可作为新的对COX-2有更高选择性活性的先导化合物。  相似文献   

6.
环氧合酶-2(Cyclooxygenase-2,COX-2)是前列腺素合成过程中一重要的限速酶,COX-2的过度表达及其前列腺素产物与多种肿瘤的发生、发展关系密切,COX-2抑制剂通过抑制肿瘤细胞增殖,诱导肿瘤细胞凋亡,阻断致癌物的代谢,减弱肿瘤介导的免疫抑制,调节抑制血管生成,抑制肿瘤细胞侵袭,环氧合酶非依赖抑癌途径,对原癌基因及抑癌基因的影响等途径影响肿瘤的发生发展,这方面的研究为针对COX-2的抗肿瘤策略打开新的视野,提供新的线索。  相似文献   

7.
环氧合酶-2(Cyclooxygenase-2,COX-2)是前列腺素合成过程中一重要的限速酶,COX-2的过度表达及其前列腺素产物与多种肿瘤的发生、发展关系密切,COX-2抑制剂通过抑制肿瘤细胞增殖,诱导肿瘤细胞凋亡,阻断致癌物的代谢,减弱肿瘤介导的免疫抑制,调节抑制血管生成,抑制肿瘤细胞侵袭,环氧合酶非依赖抑癌途径,对原癌基因及抑癌基因的影响等途径影响肿瘤的发生发展,这方面的研究为针对COX-2的抗肿瘤策略打开新的视野,提供新的线索。  相似文献   

8.
目的 从中药筛选具有潜在抑制严重急性呼吸综合征冠状病毒2 (SARS-CoV-2) 活性的成分,进一步从原子水平揭 示其抑制SARS-CoV-2 表面刺突蛋白(S 蛋白) 受体结合域(RBD) 与血管紧张素转化酶2 (ACE2) 结合的内在机制。 方法 检索新型冠状病毒(简称“新冠肺炎”) 治疗中药处方,构建“新冠肺炎中药候选活性成分数据库”。用具有ACE2 抑制活性的小分子化合物构建HipHop药效团模型,并对“新冠肺炎中药候选活性成分数据库”中活性成分筛选。采用分子 对接和分子动力学模拟方法研究候选活性成分与ACE2 的结合方式及其对SARS-CoV-2 S 蛋白与ACE2 识别的影响。 结果 本文通过中药处方挖掘和分子动力学模拟,从143 个新冠肺炎治疗中药处方中筛选出10 种可与SARS-CoV-2 S 蛋白/ 人源ACE2 识别位点结合的中药成分。其中,枇杷叶主要活性成分23-trans-p-coumaryhormentic acid 与ACE2 具有最高的亲和 力,且23-trans-p-coumaryhormentic acid 的结合可有效阻断SARS-CoV-2 S蛋白与宿主细胞ACE2 的结合。结论 本文通过虚 拟筛选发现了SARS-CoV-2 潜在抑制剂分子23-trans-p-coumaryhormentic acid,同时从原子水平预测了其抑制SARS-CoV-2 S 蛋白与ACE2 结合的内在机制,这将为SARS-CoV-2 特异性抗病毒药物的研发提供理论依据。  相似文献   

9.
罗成  杨叶  赵勤实 《生命科学》2008,20(1):76-80
本文回顾环氧化酶-2(COX-2)抑制剂的发展史和分析新的筛选方法:如平衡抑制剂对COX-1/COX-2的选择性,寻找双靶点或多靶点的抑制剂。在计算机辅助药物设计中结合更多的灵活的动力学原理,在天然分子的基础上设计新的药物分子,辅以脂质体包裹剂型实现药物靶向投递,以图研究出新一代更为安全的COX-2抑制剂来预防、控制癌症和其他疾病。  相似文献   

10.
目的 有效结合分子对接预测和表面等离子体共振实验评价技术,获得亲和力更强、序列最短的最优适配体。方法 针对前期筛选出的靶向蓖麻毒素的3条80 nt单链DNA适配体(L14、P3、L7),在明确各自二维随机区茎环序列与靶蛋白结合能力的基础上,以H-DOCK分子对接为指导,分别确定蓖麻毒素适配体随机区的最短结合单元,从而构建两端延长步进序列群,以表面等离子体共振技术测定序列群序列的亲和力和动力学参数,明确适配体的结合关键结构,从而筛选得到最优适配体。结果 3条全长适配体的随机区适配体L14r、P3r、L7r均可形成一定的茎环结构,其中L14r较L14的亲和力增强9倍、L7r增强2倍、P3r基本不变。对随机区适配体和蓖麻毒素进行分子对接,结果显示,L14r、P3r、L7r的对接分数值皆优于阴性序列40T,结合关键氨基酸个数分别为11、8、9个,存在距离小于5 ?的预测结合位点分别为20、12、15个,具有良好的与蓖麻毒素的结合能力。进一步明确了蓖麻毒素活性口袋所容纳的适配体最短结合单元L14rm、P3rm、L7rm的序列构成,在此基础上构建出两端延长步进序列群。针对该步进群,基于结合关键氨基酸个数、结合位点个数、对接得分等参数的变化和表面等离子体共振测定结果筛选出最优适配体。所获得的最优适配体L14rm、L7rm-2亲和力继续增强了1~2倍。结论 随机区适配体能有效地与蓖麻毒素结合,较之全长适配体亲和力更强,分子对接结合步进序列群设计,仅使用17条序列,便有效获得了3条最优适配体并明确其结合作用。3条结合蓖麻毒素的最优适配体——L14rm、P3r、L7rm-2的KD值分别为(64±30)、(167±19)、(120±1)nmol/L,亲和力提高到全长适配体的14、1、4倍。  相似文献   

11.
Abstract

The oncogenic kinase PAK1 (p21-activated kinase 1) is involved in developing many diseases including cancers, neurofibromatosis, Alzheimer's disease, diabetes (type 2), and hypertension. Thus, it is thought to be a prominent therapeutic target, and its selective inhibitors have a huge market potential. Recently, herbal PAK1 inhibitors have gained immense interest over synthetic ones mainly due to their non-toxic effects. Till date, many herbal compounds have been suggested to inhibit PAK1, but their information on selectivity, bioavailability, ADMET (absorption, distribution, metabolism, excretion, and toxicity) properties, and molecular interactions with PAK1 has not been explored. Hence, this study was designed with computational approaches to explore and identify the best herbal PAK1-blockers showing good ADMET properties, druggable features and binding affinity with PAK1. Herbal inhibitors reported here were initially filtered with Lipinski’s rule of five (RO5). Then, molecular docking between these inhibitors and PAK1 catalytic sites was performed using AutoDock Vina and GOLD suite to determine the binding affinity and interactions. Finally, 200?ns molecular dynamics (MD) simulations on three top-ranked inhibitors including cucurbitacin I (C-I), nymphaeol A (NA), and staurosporine (SPN) were carried out. The binding free energies and interactions revealed that NA can strongly bind with the PAK1 catalytic cleft. PASS prediction and ADMET profiling supported that NA is appeared to be a more selective and safer inhibitor than C-I and SPN. These results conform to the previous experimental evidences, and therefore, NA from Okinawa propolis could be a promising inhibitor for treating PAK1-dependent illnesses.

Communicated by Ramaswamy H. Sarma  相似文献   

12.
Cyclooxygenase-2 (COX-2) is an important enzyme responsible for the formation of potent inflammatory mediators like prostaglandins, prostacyclin and thromboxane. Hence, inhibition of COX-2 is one of the best ways to control the inflammation. Non-steroidal anti-inflammatory drugs can control inflammation by inhibiting Cyclooxygenase. Selective inhibition of COX-2 is preferable over the inhibition of COX-1 because of the fewer adverse effects produced. Molecular modeling and docking of 134 selected indole compounds were done against COX-2. The pharmacophore-based in silico structural modifications of the best scored compounds were carried out in order to enhance the binding affinity and selectivity. The modification resulted in derivatives with better binding energies than that of known COX-2 inhibitors. The four best derivatives in terms of the binding energies were selected and their binding stabilities were studied by molecular dynamics simulation methods.  相似文献   

13.
Abstract

Drug discovery for a vigorous and feasible lead candidate is a challenging scientific mission as it requires expertise, experience, and huge investment. Natural products and their derivatives having structural diversity are renowned source of therapeutic agents since many years. Tyrosol (a natural phenylethanoid) has been extracted from olive oil, and its structure was confirmed by elemental analysis, FT-IR, FT-NMR, and single crystal X-ray crystallography. The conformational analysis for tyrosol geometry was performed by Gaussian 09 in terms of density functional theory. Validation of bond lengths and bond angles obtained experimentally as well as theoretically were performed with the help of curve fitting analysis, and values of correlation coefficient (R) obtained as 0.988 and 0.984, respectively. The charge transfer within the tyrosol molecule was confirmed by analysis of HOMO→LUMO molecular orbitals. In molecular docking with COX-2 (PDB ID: 5F1A), tyrosol was found to possess satisfactory binding affinity as compared to other NSAIDs (Aspirin, Ibuprofen, and Naproxen) and a COX-2 selective drug (Celecoxib). ADMET prediction, drug-likeness and bioactivity score altogether confirm the lead/drug like potential of tyrosol. Further investigation of simulation quality plot, RMSD and RMSF plots, ligands behavior plot as well as post simulation analysis manifest the consistency of 5F1A-tyrosol complex throughout the 20?ns molecular simulation process that signifies its compactness and stability within the receptor pocket. Abbreviations ADMET Absorption, Distribution, Metabolism, Excretion and Toxicity

Å Angstrom

COX-2 Cyclooxygenase-2

DFT Density Functional Theory

DMF Dimethylformamide

FMO Frontier Molecular Orbital

FT-IR Fourier-transform Infrared Spectroscopy

FT-NMR Nuclear Magnetic Resonance Spectroscopy

HOMO Highest Occupied Molecular Orbital

LUMO Lowest Unoccupied Molecular Orbital

MD Molecular Dynamics

NS Nanosecond

NSAIDs Non-steroidal anti-inflammatory drugs

OPE Osiris Property Explorer

RMSD Root-Mean-Square Deviation

RMSF Root Sean Square Fluctuation

Communicated by Ramaswamy H. Sarma  相似文献   

14.
Natural products acquire massive structural and chemical diversity, which cannot be coordinated by any synthetic libraries for small molecules and they are continuing to inspire novel discoveries in health sciences. We have performed the computational calculations for geometry optimization and prediction of electronic and structural properties of some plant phenolic compounds through Gaussian 09 program. Energies of molecular orbitals were computed, to mimic out the stabilities arising from charge delocalization and intramolecular interactions. This process indicated the eventual charge transfer within the molecules. The molecular docking and ADMET properties of these compounds with a novel anticancer (HER2) and anti-inflammatory (COX-2) targets revealed that two molecules were capable of inhibiting both the targets, and could be used as multi target inhibitors. Furthermore, molecular dynamics simulation studies were performed to elucidate the binding mechanism and the comparison of inhibitor’s binding mode with diverse biological activities as anticancer and anti-inflammatory agents. A high-quality association was reported among quantum chemical, ADMET, docking, dynamics and MMGBSA results.

Communicated By Ramaswamy H. Sarma  相似文献   


15.
We recently reported that the hydroxyiminoethanone derivative, (E)-OXM, behaves as a highly selective COX-1 inhibitor (COX-1 SI = 833), and also an interesting scaffold with unique characteristics. In the current study, a comprehensive crystallographic and computational study was performed to elucidate its conformational stability and pharmacological activity. Its conformational energy was studied at the B3LYP/6-311G** level of theory and compared to the single-crystal X-ray diffraction data. In addition, computational studies of three structurally different stilbenoid derivatives used as selective COX-1 or COX-2 inhibitors were undertaken to predict their COX selectivity potentials. Flexible docking was performed for all compounds at the active site of both COX-1 and COX-2 enzymes by considering some of the key residues as flexible during the docking operation. In the next step, molecular dynamic simulation and binding free energy calculations were performed by MM-PBSA. Final results were found to be highly dependent on the atomic charges of the inhibitors and the choice of force field used to calculate the atomic charges. The binding conformation of the hydroxyiminoethanone derivative is highly correlated with the type of COX isoform inhibited. Our predictive approach can truly predict the cyclooxygenase inhibition selectivity of stilbenoid inhibitors.  相似文献   

16.
Cyclooxygenase-2 (COX-2) produces prostaglandins in inflamed tissues and hence has been considered as an important target for the development of anti-inflammatory drugs since long. Administration of traditional non-steroidal anti-inflammatory drugs (NSAIDs) and other COX-2 selective inhibitors (COXIBS) for the treat of inflammation has been found to be associated with side effects, which mainly includes gastro-intestinal (GI) toxicity. The present study involves developing a virtual library of novel molecules with high druglikeliness using structure-based de novo drug designing and 2D fingerprinting approach. A library of 2657 drug like molecules was generated. 2D fingerprinting based screening of the designed library gave a unique set of compounds. Molecular docking approach was then used to identify two compounds highly specific for COX-2 isoform. Molecular dynamics simulations of protein-ligand complexes revealed that the candidate ligands were dynamically stable within the cyclooxygenase binding site of COX-2. The ligands were further analyzed for their druglikeliness, ADMET properties and synthetic accessibility using knowledge based set of rules. The results revealed that the molecules are predicted to selectively bind to COX-2 enzyme thereby potentially overcoming the limitations posed by the drugs in clinical use.  相似文献   

17.
Designed multi-target ligand (DML) is an emerging strategy for the development of new drugs and involves the engagement of multiple targets with the same moiety. In the context of NSAIDs it has been suggested that targeting the thromboxane prostanoid (TP) receptor along with cyclooxygenase-2 (COX-2) may help to overcome cardiovascular (CVS) complications associated with COXIBs. In the present work, azaisoflavones were studied for their COX-2 and TP receptor binding activities using structure based drug design (SBDD) techniques. Flavonoids were selected as a starting point based on their known COX-2 inhibitory and TP receptor antagonist activity. Iterative design and docking studies resulted in the evolution of a new class scaffold replacing the benzopyran-4-one ring of flavonoids with quinolin-4-one. The docking and binding parameters of these new compounds are found to be promising in comparison to those of selective COX-2 inhibitors, such as SC-558 and celecoxib. Owing to the lack of structural information, a model for the TP receptor was generated using a threading base alignment method with loop optimization performed using an ab initio method. The model generated was validated against known antagonists for TP receptor using docking/MMGBSA. Finally, the molecules that were designed for selective COX-2 inhibition were docked into the active site of the TP receptor. Iterative structural modifications and docking on these molecules generated a series which displays optimum docking scores and binding interaction for both targets. Molecular dynamics studies on a known TP receptor antagonist and a designed molecule show that both molecules remain in contact with protein throughout the simulation and interact in similar binding modes.
Graphical abstract ?
  相似文献   

18.
BackgroundCyclooxygenase-2 (COX-2) is an important enzyme with numerous biological functions. Overexpression of COX-2 has been associated with various inflammatory-related diseases and therefore, projected as an important pharmacological target.PurposeWe aimed to investigate the inhibitory potential of isolated bioactive compounds, 3-caffeoyl-4-dihydrocaffeoyl quinic acid (CDQ) and isorhamnetin 3-O-β-d-glucopyranoside (IDG), from Salicornia herbacea against COX-2 using both computational and in vitro approaches.MethodsComputational analysis, including molecular docking, molecular dynamics (MD) simulations, and post-simulations analysis, were employed to estimate the binding affinity and stability of CDQ and IDG in the catalytic pocket of COX-2 against Celecoxib as positive control. These predictions were further evaluated using in vitro enzyme inhibition as well as gene expression mediation in macrophages cells.ResultsMolecular docking analysis revealed substantial binding energy of CDQ (-6.1 kcal/mol) and IDG (-5.9 kcal/mol) with COX-2, which are lower than Celecoxib (-8.1 kcal/mol). MD simulations (100 ns) and post simulation analysis exhibited the substantial stability and binding affinity of docked CDQ and IDG compounds with COX-2. In vitro assays indicated significant COX-2 inhibition by CDQ (IC50 = 76.91 ± 2.33 μM) and IDG (IC50 = 126.06 ± 9.44 μM). This result supported the inhibitory potential of isolated bioactive compounds against COX-2. Also, a cellular level study revealed a downregulation of COX-2 expression in tumor necrosis factor-alpha stimulated RAW 264.7 macrophages treated with CDQ and IDG.ConclusionComputational and experimental analysis of CDQ and IDG from S. herbacea established their potential in the inhibition and mediation of COX-2. Hence, CDQ and IDG can be considered for therapeutic development against COX-2 linked disorders, such as inflammation and cancer. Furthermore, CDQ and IDG structures can be served as a lead compound for the development of advanced novel anti-inflammatory drugs.  相似文献   

19.
Wee1-like protein kinase (Wee1) is a tyrosine kinase that regulates the G2 checkpoint and prevents entry into mitosis in response to DNA damage. Based on a series of signaling pathways initiated by Wee1, Wee1 has been recognized as a potential target for cancer therapy. To discover potent Wee1 inhibitors with novel scaffolds, ligand-based pharmacophore model has been built based on 101 known Wee1 inhibitors. Then the best pharmacophore model, AADRRR.340, with good partial least square (PLS) statistics (R2?=?0.9212, Q2?=?0.7457), was selected and validated. The validated model was used as a three-dimensional (3D) search query for databases virtual screening. The filtered molecules were further analyzed and refined by Lipinski’s rule of 5, multiple docking procedures (high throughput virtual screening (HTVS), standard precision (SP), genetic optimization for ligand docking (GOLD), extra precision (XP), and unique quantum polarized ligand docking (QPLD)); absorption, distribution, metabolism, excretion, and toxicity (ADMET) screening; and the Prime/molecular mechanics generalized born surface area (MM-GBSA) method binding free energy calculations. Eight leads were identified as potential Wee1 inhibitors, and a 50?ns molecular dynamics (MD) simulation was carried out for top four inhibitors to predict the stability of ligand–protein complex. Molecular mechanics Poisson–Boltzmann surface area (MM-PBSA) based on MD simulation and the energy contribution per residue to the binding energy were calculated. In the end, three hits with good stabilization and affinity to protein were identified.

Communicated by Ramaswamy H. Sarma  相似文献   


20.
Matrix metalloproteinase-9 (MMP-9) has been considered as an attractive target involving cancer therapy. In this study, the 3D QSAR pharmacophore model of MMP-9 inhibitors is built, and its reliability is subsequently validated based on different methods. The built pharmacophore model consists of the four chemical features, including two hydrogen bond acceptors (HBA), one hydrophobic (HY), and one ring aromatic (RA). Among them, both HY and RA are found to be especially important features because they involve the interactions of inhibitors with the S1′ pocket of MMP-9, which determines the selectivity of MMP-9 inhibitors. By combining pharmacophore model with molecular docking, the virtual screening is carried out to identify the selective MMP-9 inhibitors from natural products. The four potential selective MMP-9 inhibitors of natural products are found. One of them was used to carry out the bioassay experiment inhibiting MMP-9, and the estimated IC50 value of only 26.94 µM clearly shows its strongly inhibitory activity; besides, both the hybrid quantum mechanics/molecular mechanics (QM/MM) calculation and the molecular dynamics simulation are performed to examine the reliability regarding the binding mode of this inhibitor with MMP-9 active sites predicted by molecular docking. All the screened four natural products are found to well bind with the MMP-9 active sites by different kinds of interactions. Finally, the ADMET properties of screened four natural products are assessed. These screened MMP-9 inhibitors of natural products could be used as the lead compounds to perform structural modifications and optimizations in the future work.

Communicated by Ramaswamy H. Sarma  相似文献   


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