| 1. |
- Briggner, Lars-Erik, et al.
(författare)
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In Silico Solid State Perturbation for Solubility Improvement
- 2014
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Ingår i: ChemMedChem. - : Wiley. - 1860-7179 .- 1860-7187. ; 9:4, s. 724-726
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Tidskriftsartikel (refereegranskat)abstract
- Solubility is a frequently recurring issue within pharmaceutical industry, and new methods to proactively resolve this are of fundamental importance. Here, a novel methodology is reported for intrinsic solubility improvement, using insilico prediction of crystal structures, by perturbing key interactions in the crystalline solid state. The methodology was evaluated with a set of benzodiazepine molecules, using the two-dimensional molecular structure as the only a priori input. The overall trend in intrinsic solubility was correctly predicted for the entire set of benzodiazepines molecules. The results also indicate that, in drug compound series where the melting point is relatively high (i.e., brick dust compounds), the reported methodology should be very suitable for identifying strategically important molecular substitutions to improve solubility. As such, this approach could be a useful predictive tool for rational compound design in the early stages of drug development.
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| 2. |
- Erdelyi, Mate, 1975, et al.
(författare)
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The Binding Mode of Side Chain- and C3-Modified Epothilones to Tubulin
- 2010
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Ingår i: ChemMedChem. - : Wiley. - 1860-7179 .- 1860-7187. ; 5:6, s. 911-920
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Tidskriftsartikel (refereegranskat)abstract
- The tubulin-binding mode of C3- and C15-modified analogues of epothilone A (Epo A) was determined by NMR spectroscopy and computational methods and compared with the existing structural models of tubulin-bound natural Epo A. Only minor differences were observed in the conformation of the macrocycle between Epo A and the C3-modified analogues investigated. In particular, 3-deoxy- (compound 2) and 3-deoxy-2,3-didehydro-Epo A (3) were found to adopt similar conformations in the tubulin-binding cleft as Epo A, thus indicating that the 3-OH group is not essential for epothilones to assume their bioactive conformation. None of the available models of the tubulin-epothilone complex is able to fully recapitulate the differences in tubulin-polymerizing activity and microtubule-binding affinity between C20-modified epothilones 6 (C20-propyl), 7 (C20-butyl), and 8 (C20-hydroxypropyl). Based on the results of transferred NOE experiments in the presence of tubulin, the isomeric C15 quinoline-based Epo B analogues 4 and 5 show very similar orientations of the side chain, irrespective of the position of the nitrogen atom in the quinoline ring. The quinoline side chain stacks on the imidazole moiety of -His227 with equal efficiency in both cases, thus suggesting that the aromatic side chain moiety in epothilones contributes to tubulin binding through strong van der Waals interactions with the protein rather than hydrogen bonding involving the heteroaromatic nitrogen atom. These conclusions are in line with existing tubulin polymerization and microtubule-binding data for 4, 5, and Epo B.
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| 3. |
- Fritzson, Ingela, et al.
(författare)
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Inhibition of Human DHODH by 4-Hydroxycoumarins, Fenamic Acids, and N-(Alkylcarbonyl)anthranilic Acids Identified by Structure-Guided Fragment Selection
- 2010
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Ingår i: ChemMedChem. - : Wiley. - 1860-7187 .- 1860-7179. ; 5:4, s. 608-617
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Tidskriftsartikel (refereegranskat)abstract
- A strategy that combines virtual screening and structureguided selection of fragments was used to identify three unexplored classes of human DHODH inhibitor compounds: 4-hydroxycoumarins, fenamic acids, and N-(alkylcarbonyl)anthranilic acids. Structure-guided selection of fragments targeting the inner subsite of the DHODH ubiquinone binding site made these findings possible with screening of fewer than 300 fragments in a DHODH assay. Fragments from the three inhibitor classes identified were subsequently chemically expanded to target an additional subsite of hydrophobic character. All three classes were found to exhibit distinct structure–activity relationships upon expansion. The novel N-(alkylcarbonyl anthranilic acid class shows the most promising potency against human DHODH, with IC50 values in the low nanomolar range. The structure of human DHODH in complex with an inhibitor of this class is presented.
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| 4. |
- Gaugaz, Fabienne Z, et al.
(författare)
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The impact of cyclopropane configuration on the biological activity of cyclopropyl-epothilones
- 2014
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Ingår i: ChemMedChem. - : Wiley. - 1860-7179 .- 1860-7187. ; 9:10, s. 2227-2232
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Tidskriftsartikel (refereegranskat)abstract
- Two cis-12,13-cyclopropyl-epothilone B variants have been synthesized, differing only in the configuration of the stereocenters at C12 and C13. The syntheses were based on a common allylic alcohol intermediate that was converted into the corresponding diastereomeric hydroxymethyl-cyclopropanes by means of stereoselective Charette cyclopropanations. Macrocyclizations were accomplished through ring-closing metathesis (RCM). Substantial differences between the two compounds were found with regard to microtubule binding affinity, antiproliferative activity and their effects on the cellular microtubule network. While the analogue with the cyclopropane moiety oriented in a corresponding way to the epoxide configuration in natural epothilones was almost equipotent with epothilone A, the other was significantly less active. Based on these findings, natural epothilone-like activity of cis-fused 12,13-cyclopropyl-epothilone analogues is tightly linked to the natural orientation of the cyclopropane moiety.
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| 5. |
- Honarparvar, Bahareh, et al.
(författare)
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Pentacycloundecane-diol-Based HIV-1 Protease Inhibitors : Biological Screening, 2D NMR, and Molecular Simulation Studies
- 2012
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Ingår i: ChemMedChem. - : Wiley. - 1860-7179 .- 1860-7187. ; 7:6, s. 1009-1019
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Tidskriftsartikel (refereegranskat)abstract
- Novel compounds incorporating a pentacycloundecane (PCU) diol moiety were designed, synthesized, and evaluated as inhibitors of the wild-type C-South African (C-SA) HIV-1 protease. Seven compounds are reported herein, three of which displayed IC50 values in the 0.50.6 mu M range. The cytotoxicity of PCU cage peptides toward human MT-4 cells appears to be several orders of magnitude less toxic than the current antiviral medications ritonavir and lopinavir. NMR studies based on the observed through-space 1H,1H distances/contacts in the EASY-ROESY spectra of three of the considered PCU peptide inhibitors enabled us to describe their secondary solution structure. Conserved hydrogen bonding interactions were observed between the hydroxy group of the PCU diol inhibitors and the catalytic triad (Asp25, Ile26, Gly27) of HIV protease in docking and molecular dynamics simulations. The biological significance and possible mode of inhibition by PCU-based HIV protease inhibitors discussed herein facilitates a deeper understanding of this family of inhibitors and their potential application to a vast number of alternative diseases related to proteases.
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| 6. |
- Horvath, Dragos, et al.
(författare)
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Design of a general-purpose European compound screening library for EU-OPENSCREEN
- 2014
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Ingår i: ChemMedChem. - : Wiley. - 1860-7179 .- 1860-7187. ; 9:10, s. 2309-2326
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Tidskriftsartikel (refereegranskat)abstract
- This work describes a collaborative effort to define and apply a protocol for the rational selection of a general-purpose screening library, to be used by the screening platforms affiliated with the EU-OPENSCREEN initiative. It is designed as a standard source of compounds for primary screening against novel biological targets, at the request of research partners. Given the general nature of the potential applications of this compound collection, the focus of the selection strategy lies on ensuring chemical stability, absence of reactive compounds, screening-compliant physicochemical properties, loose compliance to drug-likeness criteria (as drug design is a major, but not exclusive application), and maximal diversity/coverage of chemical space, aimed at providing hits for a wide spectrum of drugable targets. Finally, practical availability/cost issues cannot be avoided. The main goal of this publication is to inform potential future users of this library about its conception, sources, and characteristics. The outline of the selection procedure, notably of the filtering rules designed by a large committee of European medicinal chemists and chemoinformaticians, may be of general methodological interest for the screening/medicinal chemistry community. The selection task of 200K molecules out of a pre-filtered set of 1.4M candidates was shared by five independent European research groups, each picking a subset of 40K compounds according to their own in-house methodology and expertise. An in-depth analysis of chemical space coverage of the library serves not only to characterize the collection, but also to compare the various chemoinformatics-driven selection procedures of maximal diversity sets. Compound selections contributed by various participating groups were mapped onto general-purpose self-organizing maps (SOMs) built on the basis of marketed drugs and bioactive reference molecules. In this way, the occupancy of chemical space by the EU-OPENSCREEN library could be directly compared with distributions of known bioactives of various classes. This mapping highlights the relevance of the selection and shows how the consensus reached by merging the five different 40K selections contributes to achieve this relevance. The approach also allows one to readily identify subsets of target-or target-class-oriented compounds from the EU-OPENSCREEN library to suit the needs of the diverse range of potential users. The final EU-OPENSCREEN library, assembled by merging five independent selections of 40K compounds from various expert groups, represents an excellent example of a Europe-wide collaborative effort toward the common objective of building best-in-class European open screening platforms.
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| 7. |
- Malo, Marcus, et al.
(författare)
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Investigation of D1 receptor-agonist interactions and D1/D2 agonist selectivity using a combination of pharmacophore and receptor homology modelling
- 2012
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Ingår i: ChemMedChem. - : Wiley. - 1860-7179 .- 1860-7187. ; 7:3, s. 483-494
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to use a combined structure and pharmacophore modeling approach to extract information regarding dopamine D1 receptor agonism and D1/D2 agonist selectivity. A 3D structure model of the D1 receptor in its agonist-bound state was constructed with a full D1 agonist present in the binding site. Two different binding modes were identified using (+)-doxanthrine or SKF89626 in the modeling procedure. The 3D model was further compared with a selective D1 agonist pharmacophore model. The pharmacophore feature arrangement was found to be in good agreement with the binding site composition of the receptor model, but the excluded volumes did not fully reflect the shape of the agonist binding pocket. A new receptor-based pharmacophore model was developed with forbidden volumes centered on atom positions of amino acids in the binding site. The new pharmacophore model showed a similar ability to discriminate as the previous model. A comparison of the 3D structures and pharmacophore models of D1 and D2 receptors revealed differences in shape and ligand-interacting features that determine selectivity of D1 and D2 receptor agonists. A hydrogen bond pharmacophoric feature (Ser-TM5) was shown to contribute most to the selectivity. Non-conserved residues in the binding pocket that strongly contribute to D1/D2 receptor agonist selectivity were also identified; those were Ser/Cys3.36, Tyr/Phe5.38, Ser/Tyr5.41, and Asn/His6.55 in the transmembrane (TM) helix region, together with Ser/Ile and Leu/Asn in the second extracellular loop (EC2). This work provides useful information for the design of new selective D1 and D2 agonists. The combined receptor structure and pharmacophore modeling approach is considered to be general, and could therefore be applied to other ligand–protein interactions for which experimental information is limited.
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| 8. |
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| 9. |
- Malo, Marcus, et al.
(författare)
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Selective pharmacophore models of dopamine D(1) and D(2) full agonists based on extended pharmacophore features.
- 2010
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Ingår i: ChemMedChem. - : Wiley. - 1860-7187 .- 1860-7179. ; 5:2, s. 232-46
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Tidskriftsartikel (refereegranskat)abstract
- This study is focused on the identification of structural features that determine the selectivity of dopamine receptor agonists toward D(1) and D(2) receptors. Selective pharmacophore models were developed for both receptors. The models were built by using projected pharmacophoric features that represent the main agonist interaction sites in the receptor (the Ser residues in TM5 and the Asp in TM3), a directional aromatic feature in the ligand, a feature with large positional tolerance representing the positively charged nitrogen in the ligand, and sets of excluded volumes reflecting the shapes of the receptors. The sets of D(1) and D(2) ligands used for modeling were carefully selected from published sources and consist of structurally diverse, conformationally rigid full agonists as active ligands together with structurally related inactives. The robustness of the models in discriminating actives from inactives was tested against four ensembles of conformations generated by using different established methods and different force fields. The reasons for the selectivity can be attributed to both geometrical differences in the arrangement of the features, e.g., different tilt angels of the pi system, as well as shape differences covered by the different sets of excluded volumes. This work provides useful information for the design of new D(1) and D(2) agonists and also for comparative homology modeling of D(1) and D(2) receptors. The approach is general and could therefore be applied to other ligand-protein interactions for which no experimental protein structure is available.
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| 10. |
- Sehgelmeble, Fernando, et al.
(författare)
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Sulfonimidamides as Sulfonamides Bioisosteres : Rational Evaluation through Synthetic, in Vitro, and in Vivo Studies with γ-Secretase Inhibitors
- 2012
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Ingår i: ChemMedChem. - : Wiley. - 1860-7179 .- 1860-7187. ; 7:3, s. 396-399
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Tidskriftsartikel (refereegranskat)abstract
- The proof of the pudding: A proof-of-concept study using γ-secretase inhibitors as a model has shown that sulfonimidamides act as bioisosteres for sulfonamides. Detailed in vitro and in vivo profiling reveal that the sulfonimidamide motif imparts desirable properties such as decreased lipophilicity and plasma protein binding, accompanied by increased solubility. Our data support a wider use of this unique functional group in the design of new pharmacologically active agents.
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