scholarly journals Structure-activity relationship study of steroidal 1,2,4,5-tetraoxane animalarials using computational procedures

2005 ◽  
Vol 70 (3) ◽  
pp. 329-345 ◽  
Author(s):  
Apurba Bhattacharjee ◽  
Keith Carvalho ◽  
Dejan Opsenica ◽  
Bogdan Solaja
Keyword(s):  
Hydrogen Bond ◽  
Antimalarial Activity ◽  
Three Dimensional ◽  
Pharmacophore Model ◽  
Plasmodium Falciparum Malaria ◽  
Multidrug Resistant ◽  
Heme Iron ◽  
Hydrogen Bond Acceptor ◽  
Computational Procedures

A three-dimensional QSAR pharmacophore model for antimalarial activity of steroidal 1,2,4,5-tetraoxanes was developed from a set of 17 substituted antimalarial derivatives out of 27 analogues that exhibited remarkable in vitro activity (below 100 ng/mL) against sensitive and multidrug-resistant Plasmodium falciparum malaria. The pharmacophore, which contains two hydrogen bond acceptors (lipid) and one hydrophobic (aliphatic) feature, was found to map well onto the potent analogues and many other well-known antimalarial trioxane drugs including artemisinin, arteether, artesunic acid, and tetraoxanes. The presence of at least one hydrogen bond acceptor in the trioxane or the tetraoxane moiety appears to be necessary for potent activity of this class of compounds. Docking calculations of some of these compounds with heme are consistent with the above observation as the proximity of the heme iron to the oxygen atom of the trioxane or the tetraoxane moiety favors potent activity of the compounds. Electron transfer from the oxygen of trioxane or the tetraoxane appears to be crucial for mechanism of action of the compounds. This information together with the pharmacophore should enable search for new peroxide containing antimalarial candidates from databases and custom designed synthesis of more efficacious and safer analogues.

scholarly journals Efficacy of Proton Pump Inhibitor Drugs against Plasmodium falciparum In Vitro and Their Probable Pharmacophores

2002 ◽  
Vol 46 (8) ◽  
pp. 2627-2632 ◽  
Author(s):  
Michael A. Riel ◽  
Dennis E. Kyle ◽  
Apurba K. Bhattacharjee ◽  
Wilbur K. Milhous
Keyword(s):  
Plasmodium Falciparum ◽  
Quantum Chemical ◽  
Three Dimensional ◽  
Pharmacophore Model ◽  
Multidrug Resistant ◽  
Computational Techniques ◽  
Chemical Methods ◽  
Hydrogen Bond Acceptor ◽  
Quantum Chemical Methods

ABSTRACT The substituted benzimidazoles omeprazole, lansoprazole, rabeprazole, and pantoprazole were found to have in vitro activity against three different isolates of Plasmodium falciparum: D6 (which is chloroquine and pyrimethamine sensitive), W2 (chloroquine and pyrimethamine resistant), and TM91C235 (multidrug resistant). Lansoprazole and rabeprazole were the most effective against all three isolates, with a 50% inhibitory concentration (IC50) range of 7 to 11 μM. Omeprazole showed intermediate activity against D6 and W2 isolates, with IC50s of 27 to 28 μM, but had poor activity against TM91C235, with an IC50 of 76 μM. Pantoprazole was the least effective, with IC50s of 73 μM against D6, 53 μM against W2, and 39 μM against TM91C235. A pharmacophore model describing the important features responsible for potent activity of the drugs was developed using computational techniques of semiempirical quantum chemical methods and the three-dimensional QSAR procedure of the CATALYST software. The important features of the pharmacophore, according to the findings based on the CATALYST procedures, are the hydrogen bond acceptor and donor sites at the benzimidine nitrogen atoms and the two aromatic hydrophobic sites in the molecules. AM1 quantum chemical calculations identified the electrostatic potential surface surrounding the sulfoxide atom as crucial for potent activity.

Pharmacophore-based screening for identification of Human Acyl-CoA cholesterol acyltransferase inhibitors: An in-silico study

2020 ◽  
Vol 18 ◽  
Author(s):  
Ankit Dhaundiyal ◽  
Puja Kumari ◽  
Shasta Kalra
Keyword(s):  
Hydrogen Bond ◽  
Cholesterol Acyltransferase ◽  
Three Dimensional ◽  
Pharmacophore Model ◽  
Fatty Acyl ◽  
Hydrogen Bond Donor ◽  
Data Set ◽  
Hydrogen Bond Acceptor ◽  
Discovery Studio ◽  
Acyltransferase Inhibitors

Abstract:: Human Acyl-CoA cholesterol acyltransferase (ACAT) plays an important role in catalysis of reaction which converts cholesterol into cholesteryl esters and long-chain fatty acyl coenzyme A. The inhibition of ACAT has therapeutically potential roles in hypercholestrolemia, atherosclerosis and coronary heart disease. For better understanding of essential chemical features for ACAT inhibition and identifying novel inhibitors, a three-dimensional (3D) chemical-feature-based quantitative QSAR pharmacophore model for available ACAT inhibitors have been developed for first time using Discovery Studio 2.5. The best model (Hypo1) having lowest total cost (84.14), highest cost difference (69.67), highest correlation coefficient (0.94), and lowest RMS (1.15Å), constitutes of one hydrogen bond acceptor, one hydrogen bond donor, two hydrophobic aromatic and one hydrophobic aliphatic feature. Validation of Hypo1 was further done using test set activity prediction, Fischer’s randomization method and decoy data set to check the reliability of the model. The validated Hypo1 was then used as a 3D search query for virtual screening to retrieve potential inhibitors from National cancer institute (NCI), ChemDiv and Specs databases. Finally, ADMET properties of selected compounds were calculated. The result shows the good potential of the newly found ACAT inhibitors. Finally, the two compounds have been obtained as novel hits to design the Novel ACAT inhibitors.

scholarly journals DESIGN AND SYNTHESIS OF SOME NEWER IMIDAZOLYL HETEROCYCLES AS POTENT BTK INHIBITORS FOR THE TREATMENT OF RHEUMATOID ARTHRITIS

2017 ◽  
Vol 9 (3) ◽  
pp. 80
Author(s):  
R. Priyadarsini ◽  
Anandhan Menaka
Keyword(s):  
Rheumatoid Arthritis ◽  
Hydrogen Bond ◽  
Molecular Docking ◽  
Tyrosine Kinase ◽  
Pharmacophore Model ◽  
Spectral Studies ◽  
Bruton’S Tyrosine Kinase ◽  
Bruton's Tyrosine Kinase ◽  
Hydrogen Bond Acceptor ◽  
Btk Inhibitors

Objective: The rheumatoid arthritis as a global health problem over the past few decades, Emphasizes the need for discovery of new therapeutic disease modifying anti-rheumatoid Arthritis drugs (DMARD’s). Bruton’s tyrosine kinase (BTK) is a cytoplasmic, non-receptor, tyrosine kinase which is expressed in most of the hematopoietic cells and plays an important role in the development, differentiation and proliferation of B-lineage cells, thus making BTK an efficient therapeutic target for the treatment of rheumatoid arthritis. This prompted us to synthesise a novel series of Imidazolyl Heterocycles as potent BTK (Bruton’s Tyrosine Kinase) inhibitors with alleged Anti-Rheumatoid Arthritis properties. Methods: Newer BTK inhibitors containing one hydrogen bond acceptor (HBA), one hydrogen bond donor (HBD) and three hydrophobic features based on that pharmacophore model for BTK were designed. The designed compounds were sorted by applying ADMET properties, Lipinski rule of five, molecular docking and Novelty prediction to refine the designed ligands. Finally, different five compounds containing Imidazole as the heterocyclic nucleus have been synthesized and characterized by different analytical methods like Chromatographic data, Elemental analysis and Spectral studies by IR, 1H NMR, 13C NMR, GC-MS. Molecular docking studies were performed against BTK using GLIDE 10.2. Results: Several important hydrogen bonds with BTK were revealed, which include the gatekeeper residue Glu475 and Met477 at the hinge region. Conclusion: Overall, this study suggests that the proposed ligands are found to be more effective BTK inhibitor as Anti-Rheumatoid arthritis agents.

scholarly journals Lead Optimization of Dehydroemetine for Repositioned Use in Malaria

2020 ◽  
Vol 64 (4) ◽  
Author(s):  
Priyanka Panwar ◽  
Kepa K. Burusco ◽  
Muna Abubaker ◽  
Holly Matthews ◽  
Andrey Gutnov ◽  
...  
Keyword(s):  
De Novo ◽  
Antimalarial Activity ◽  
Drug Repositioning ◽  
Multidrug Resistant ◽  
Cross Resistance ◽  
Synthetic Analogue ◽  
80S Ribosome ◽  
Content Type ◽  
Resistant Strains

ABSTRACT Drug repositioning offers an effective alternative to de novo drug design to tackle the urgent need for novel antimalarial treatments. The antiamoebic compound emetine dihydrochloride has been identified as a potent in vitro inhibitor of the multidrug-resistant strain K1 of Plasmodium falciparum (50% inhibitory concentration [IC50], 47 nM ± 2.1 nM [mean ± standard deviation]). Dehydroemetine, a synthetic analogue of emetine dihydrochloride, has been reported to have less-cardiotoxic effects than emetine. The structures of two diastereomers of dehydroemetine were modeled on the published emetine binding site on the cryo-electron microscopy (cryo-EM) structure with PDB code 3J7A (P. falciparum 80S ribosome in complex with emetine), and it was found that (−)-R,S-dehydroemetine mimicked the bound pose of emetine more closely than did (−)-S,S-dehydroisoemetine. (−)-R,S-dehydroemetine (IC50 71.03 ± 6.1 nM) was also found to be highly potent against the multidrug-resistant K1 strain of P. falciparum compared with (−)-S,S-dehydroisoemetine (IC50, 2.07 ± 0.26 μM), which loses its potency due to the change of configuration at C-1′. In addition to its effect on the asexual erythrocytic stages of P. falciparum, the compound exhibited gametocidal properties with no cross-resistance against any of the multidrug-resistant strains tested. Drug interaction studies showed (−)-R,S-dehydroemetine to have synergistic antimalarial activity with atovaquone and proguanil. Emetine dihydrochloride and (−)-R,S-dehydroemetine failed to show any inhibition of the hERG potassium channel and displayed activity affecting the mitochondrial membrane potential, indicating a possible multimodal mechanism of action.

scholarly journals The Characteristics of PD-L1 Inhibitors, from Peptides to Small Molecules

Molecules ◽  
2019 ◽  
Vol 24 (10) ◽  
pp. 1940 ◽  
Author(s):  
Yanwen Zhong ◽  
Xuanyi Li ◽  
Hequan Yao ◽  
Kejiang Lin
Keyword(s):  
Hydrogen Bond ◽  
Small Molecules ◽  
Pharmacophore Model ◽  
Amino Acid Residues ◽  
Tumor Treatment ◽  
Hydrogen Bond Donor ◽  
Treatment Results ◽  
Hydrogen Bond Acceptor ◽  
Checkpoint Pathway ◽  
Pharmacophore Models

The programmed cell death ligand protein 1 (PD-L1) is a member of the B7 protein family and consists of 290 amino acid residues. The blockade of the PD-1/PD-L1 immune checkpoint pathway is effective in tumor treatment. Results: Two pharmacophore models were generated based on peptides and small molecules. Hypo 1A consists of one hydrogen bond donor, one hydrogen bond acceptor, two hydrophobic points and one aromatic ring point. Hypo 1B consists of one hydrogen bond donor, three hydrophobic points and one positive ionizable point. Conclusions: The pharmacophore model consisting of a hydrogen bond donor, hydrophobic points and a positive ionizable point may be helpful for designing small-molecule inhibitors targeting PD-L1.

Sulfur as hydrogen-bond acceptor in cocrystals of 2-thio-modified thymine

2018 ◽  
Vol 74 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Wilhelm Maximilian Hützler ◽  
Michael Bolte
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Crystal Engineering ◽  
Rational Design ◽  
Three Dimensional ◽  
Good Reliability ◽  
Hydrogen Bond Acceptor ◽  
Hydrogen Bonding Interactions ◽  
Hydrogen Bonding Site ◽  
Hydrogen Bonded

Doubly and triply hydrogen-bonded supramolecular synthons are of particular interest for the rational design of crystal and cocrystal structures in crystal engineering since they show a high robustness due to their high stability and good reliability. The compound 5-methyl-2-thiouracil (2-thiothymine) contains an ADA hydrogen-bonding site (A = acceptor and D = donor) if the S atom is considered as an acceptor. We report herein the results of cocrystallization experiments with the coformers 2,4-diaminopyrimidine, 2,4-diamino-6-phenyl-1,3,5-triazine, 6-amino-3H-isocytosine and melamine, which contain complementary DAD hydrogen-bonding sites and, therefore, should be capable of forming a mixed ADA–DAD N—H...S/N—H...N/N—H...O synthon (denoted synthon 3s N·S;N·N;N·O), consisting of three different hydrogen bonds with 5-methyl-2-thiouracil. The experiments yielded one cocrystal and five solvated cocrystals, namely 5-methyl-2-thiouracil–2,4-diaminopyrimidine (1/2), C5H6N2OS·2C4H6N4, (I), 5-methyl-2-thiouracil–2,4-diaminopyrimidine–N,N-dimethylformamide (2/2/1), 2C5H6N2OS·2C4H6N4·C3H7NO, (II), 5-methyl-2-thiouracil–2,4-diamino-6-phenyl-1,3,5-triazine–N,N-dimethylformamide (2/2/1), 2C5H6N2OS·2C9H9N5·C3H7NO, (III), 5-methyl-2-thiouracil–6-amino-3H-isocytosine–N,N-dimethylformamide (2/2/1), (IV), 2C5H6N2OS·2C4H6N4O·C3H7NO, (IV), 5-methyl-2-thiouracil–6-amino-3H-isocytosine–N,N-dimethylacetamide (2/2/1), 2C5H6N2OS·2C4H6N4O·C4H9NO, (V), and 5-methyl-2-thiouracil–melamine (3/2), 3C5H6N2OS·2C3H6N6, (VI). Synthon 3s N·S;N·N;N·O was formed in three structures in which two-dimensional hydrogen-bonded networks are observed, while doubly hydrogen-bonded interactions were formed instead in the remaining three cocrystals whereby three-dimensional networks are preferred. As desired, the S atoms are involved in hydrogen-bonding interactions in all six structures, thus illustrating the ability of sulfur to act as a hydrogen-bond acceptor and, therefore, its value for application in crystal engineering.

Two cadmium(II) fluorous coordination compounds tuned by different bipyridines

2017 ◽  
Vol 73 (5) ◽  
pp. 424-429 ◽  
Author(s):  
Ya-Jie Kong ◽  
Peng Li ◽  
Li-Juan Han ◽  
Lu-Tong Fan ◽  
Peng-Peng Li ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Coordination Compounds ◽  
Linear Chain ◽  
Three Dimensional ◽  
Chain Structure ◽  
Water Molecules ◽  
Hydrogen Bond Acceptor ◽  
Small Surface ◽  
One Dimensional ◽  
Coordinated Water

Fluorine is the most electronegative element and can be used as an excellent hydrogen-bond acceptor. Fluorous coordination compounds exhibit several advantageous properties, such as enhanced high thermal and oxidative stability, low polarity, weak intermolecular interactions and a small surface tension compared to hydrocarbons. C—H...F—C interactions, although weak, play a significant role in regulating the arrangement of the organic molecules in the crystalline state and stabilizing the secondary structure. Two cadmium(II) fluorous coordination compounds formed from 2,2′-bipyridine, 4,4′-bipyridine and pentafluorobenzoate ligands, namely catena-poly[[aqua(2,2′-bipyridine-κ2 N,N′)(2,3,4,5,6-pentafluorobenzoato-κO)cadmium(II)]-μ-2,3,4,5,6-pentafluorobenzoato-κ2 O:O′], [Cd(C7F5O2)2(C10H8N2)(H2O)] n , (1), and catena-poly[[diaquabis(2,3,4,5,6-pentafluorobenzoato-κO)cadmium(II)]-μ-4,4′-bipyridine-κ2 N:N′], [Cd(C7F5O2)2(C10H8N2)(H2O)2] n , (2), have been synthesized solvothermally and structurally characterized. Compound (1) shows a one-dimensional chain structure composed of Cd—O coordination bonds and is stabilized by π–π stacking and O—H...O hydrogen-bond interactions. Compound (2) displays a one-dimensional linear chain structure formed by Cd—N coordination interactions involving the 4,4′-bipyridine ligand. Adjacent one-dimensional chains are extended into two-dimensional sheets by O—H...O hydrogen bonds between the coordinated water molecules and adjacent carboxylate groups. Moreover, the chains are further linked by C—H...F—C interactions to afford a three-dimensional network. In both structures, hydrogen bonding involving the coordinated water molecules is a primary driving force in the formation of the supramolecular structures.

Sub-Pharmacophore Generation of JNK3 Inhibitors

2013 ◽  
Vol 444-445 ◽  
pp. 1756-1760 ◽  
Author(s):  
Yan Ling Zhang ◽  
Yuan Ming Wang ◽  
Yan Jiang Qiao
Keyword(s):  
Hydrogen Bond ◽  
Pharmacophore Model ◽  
High Specificity ◽  
Data Bank ◽  
Chinese Herbs ◽  
Mitogen Activated Protein Kinase ◽  
Specific Class ◽  
Hydrogen Bond Donor ◽  
Hydrogen Bond Acceptor ◽  
Appraisal Index

The structure-based pharmacophore (SBP) model is consisted by the complementarity of the chemical features and space of the interaction between the ligand and receptor. The SBP models always have a high specificity which can only represent the specific class of the ligand. To simplify the models, sub-pharmacophore was then proposed in present study, and was expected to have and only have the most important or the common chemical features which play the major role in the interaction of ligand and receptor. Sub-pharmacophore should contain 4-6 features, the higher specificity with more features, and vice versa. The sub-pharmacophore was generated by the random combination of features from the structure-based models. With the MDL Drug Data Report database used as the testing database, a new metric CAI (comprehensive appraisal index), which integrated the metrics of E and A%, was defined and used to determine the best sub-pharmacophore model. C-Jun N-terminal kinase (JNKs) is one of the mitogen-activated protein kinase family, and widely involved in immune response and inflammatory response, and other pathological processes. JNK3 is mainly distributed in the brain and nervous system. In present study, twenty-five initial SBP models of JNK3 inhibitors were directly constructed from the Protein Data Bank (PDB) complexes by the LigandScout software. Then, 1018 sub-pharmacophore models were obtained from the 25 initial models. Finally, the best sub-pharmacophore was determined which was simplified from the initial model generated from the 3FI2 complex, and included four features: one hydrogen bond donor, one hydrogen bond acceptor, and two hydrophobic groups. The metrics of E, A% and CAI value of the best sub-pharmacophore model are 17.47, 31.15 and 5.44, respectively. The potential JNK3 inhibitors were then identified from Chinese herbs with the best sub-pharmacophore model, and 286 compounds were obtained.

scholarly journals Antimalarial phytochemicals as inhibitors against COVID-19 ACE2 receptor: Computational screening

2021 ◽  
Vol 13 (2) ◽  
pp. 10835
Author(s):  
Ouided BENSLAMA ◽  
Nedjwa MANSOURI ◽  
Rabah ARHAB
Keyword(s):  
Hydrogen Bond ◽  
In Silico ◽  
Pharmacophore Model ◽  
In Silico Analysis ◽  
Active Site Residues ◽  
Hydrophobic Region ◽  
Hydrogen Bond Acceptor ◽  
Computational Screening ◽  
Docking Approach ◽  
Therapeutic Molecules

Quinine, artemisinin, febrifugine, brusatol, chaparrin tehranolide, glaucarubin, sergeoliden, and yingzhaosu A, nine antimalarial phytochemicals, were the focus of an in-silico analysis aimed at discovering new therapeutic molecules against COVID-19 infection. The screening of these molecules included a molecular docking approach within the Angiotensin-converting enzyme-2 (ACE2) receptor. In addition, drug-likeness, ADMET analysis and pharmacophore mapping have been performed. The result of the docking process was based on the energy binding values as well as the number and type of interactions established with the receptor active site residues, which were compared with those of co-crystallized ligand and chloroquine. Febrifugine showed the most interesting energetic and interactive activities that were closer to the reference molecule and better than those of chloroquine. Whereas artemisinin has produced results that are the closest to those of chloroquine. Similarly, drug-likeness and ADMET analysis have shown that febrifugine and artemisinin check most of the filters and pharmacokinetic properties required for the choice of an effective therapeutic molecule. A pharmacophore model was designed on the basis of a training set consisting of the most relevant molecules; it has one metal ligator cum hydrophobic region cum hydrogen bond acceptor, one hydrogen bond acceptor cum metal ligator and one hydrophobic aromatic ring. This model is proposed to be used for the in-silico discovery of new therapeutic molecules against coronavirus.

E-pharmacophore hypothesis strategy to discover potent inhibitor for influenza treatment

2019 ◽  
Vol 18 (04) ◽  
pp. 1950021
Author(s):  
K. Rohini ◽  
Roosha Roy ◽  
K. Ramanathan ◽  
V. Shanthi
Keyword(s):  
Hydrogen Bond ◽  
Influenza A ◽  
Influenza Infection ◽  
Critical Role ◽  
Three Dimensional ◽  
Surface Protein ◽  
Enrichment Analysis ◽  
Hydrogen Bond Acceptor ◽  
Pharmacophore Hypothesis ◽  
Approved Drugs

The surface protein of Influenza virus, Neuraminidase (NA), is believed to play a critical role in the release of new viral particle and thus spreads infection. It has been recognized as a valid drug target for anti-influenza therapy. Despite the number of available approved drugs for the influenza infection treatment, the emergence of resistant variants with novel mutations are the foremost challenges for the currently used NA inhibitors. Thus, the current investigation was carried out to ascertain potent inhibitors using computational strategies such as e-pharmacophore based virtual screening and docking approach. A three-dimensional e-pharmacophore hypothesis was generated based on the chemical features of complexes of the drugs and NA protein using PHASE module of Schrödinger suite. The generated hypothesis consisted of one hydrogen bond acceptor (A), two hydrogen bond donors (D), one negatively charged group (N) and one aromatic ring (R), ADDNR. The hypothesis was further evaluated for its integrity using enrichment analysis and used to filter out molecules with similar pharmacophoric features from approved, investigational and experimental subsets of DrugBank and ZINC database. In addition, ligand filtration was performed to curb down the molecules to an efficient collection of hit molecules by using Lipinski “rule of five and ADME analysis by using Qikprop module. Overall, the results from our analysis suggest that compound lisinopril and formoterol could serve as potent antiviral compounds for the treatment of influenza A virus infection. It is worth mentioning that the results correlate well with literature evidences.

Sign in / Sign up

Export Citation Format

Share Document