| 1. |
- Berggren, Kristina, 1971, et al.
(författare)
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3-Aminopiperidine Based Peptide Analogues as the First Selective Noncovalent Inhibitors of the Bacterial Cysteine Protease IdeS
- 2012
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 55:6, s. 2549-2560
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Tidskriftsartikel (refereegranskat)abstract
- A series of eight peptides corresponding to the amino acid sequence of the hinge region of IgG and 17 newly synthesized peptide analogues containing a piperidine moiety as a replacement of a glycine residue were tested as potential inhibitors of the bacterial IgG degrading enzyme of Streptococcus pyogenes, IdeS. None of the peptides showed any inhibitory activity of IdeS, but several piperidine-based analogues were identified as inhibitors. Two different analysis methods were used: an SDS-PAGE based assay to detect IgG cleavage products and a surface plasmon resonance spectroscopy based assay to quantify the degree of inhibition. To investigate the selectivity of the inhibitors for IdeS, all compounds were screened against two other related cysteine proteases (SpeB and papain). The selectivity results show that larger analogues that are active inhibitors of IdeS are even more potent as inhibitors of papain, whereas smaller analogues that are active inhibitors of IdeS inhibit neither SpeB nor papain. Two compounds were identified that exhibit high selectivity against IdeS and will be used for further studies.
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| 2. |
- Ankner, Tobias, 1976, et al.
(författare)
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KHMDS enhanced SmI(2)-mediated reformatsky type alpha-cyanation.
- 2010
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Ingår i: Organic letters. - : American Chemical Society (ACS). - 1523-7052 .- 1523-7060. ; 12:10, s. 2210-3
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Tidskriftsartikel (refereegranskat)abstract
- A novel combination of SmI(2), KHMDS, and TsCN can be utilized to introduce a cyano group into structurally diverse and highly sensitive 2-alkyl-chroman-4-ones. Subsequent oxidation allows the formed 2-alkyl-3-cyanochromones to be isolated in yields ranging from 49 to 77%. In addition, alpha-bromoketones and esters were found to undergo equally effective alpha-cyanation.
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| 3. |
- Artursson, Per, et al.
(författare)
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Caco-2 monolayers in experimental and theoretical predictions of drug transport
- 2012
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Ingår i: Advanced Drug Delivery Reviews. - : Elsevier BV. - 0169-409X .- 1872-8294. ; 64:S, s. 280-289
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Forskningsöversikt (refereegranskat)abstract
- This review examines the use of Caco-2 monolayers in the prediction of intestinal drug absorption. First, the different routes of drug transport in Caco-2 monolayers are compared with those seen in vivo. Second, the prediction of drug absorption in vivo from transport experiments in cell monolayers is discussed for different classes of drugs. Finally, the use of Caco-2 monolayers as a reference model in physico-chemical and theoretical predictions of drug absorption is discussed. We conclude that Caco-2 monolayers can be used to identify drugs with potential absorption problems, and possibly also to select drugs with optimal passive absorption characteristics from series of pharmacologically active molecules generated in drug discovery programs.
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| 4. |
- Delaine, Tamara, 1981, et al.
(författare)
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A structure activity relationship study of geranial derivatives
- 2012
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Ingår i: Contact Dermatitis 11th congress of the European society of contact dermatitis (ESCD) 13-16 june 2012, Malmö, Sweden. - : Wiley. ; 66:Suppl. 2
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Konferensbidrag (refereegranskat)abstract
- Background: Fragrances are common causes of contact allergy. Skin exposure to geranial is frequent since citral (mixture of geranial and neral) is commonly used in fragrances and flavors and is considered as a moderate allergen. Previous studies according to the local lymphnodeassay (LLNA)in micehaverevealed large variations in the sensitizing capacity of different geranial derivatives. Objectives: For a better understanding of these variations, a structure-activity relationship (SAR) study on a series of derivatives of geranial was carried out. Methods: The chemical reactivity of the compounds towards a model peptide was investigated using LC-MS. The adduct formation and the non-reacted peptide depletion were monitored. Adducts formed with model amino acids were investigated and structural determination was performed. Additional derivatives were synthesized and their sensitization potencies were evaluated in relation to their physicochemical and reactivity properties. Results: Most of the derivatives were shown to bind covalently to the cysteine residue of the model peptide. The percentage of depletion of the non-reacted peptide ranged from 0% to 100% after 24 hr, constant rate of depletion revealed a large difference between the fastest and lowest reacting derivatives. These resultswere congruent with the skin sensitization potencies obtained with the LLNA. Conclusions: A good correlation between the reactivity and the sensitizing potency was observed. Small changes in the chemical structure of geranial result in significant differences in sensitizing capacity and chemical reactivity. Conflicts of interest: The authors have declared no conflicts.
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| 5. |
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| 6. |
- Delaine, Tamara, 1981, et al.
(författare)
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Epoxyalcohols: bioactivation and conjugation required for skin sensitization.
- 2014
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Ingår i: Chemical research in toxicology. - : American Chemical Society (ACS). - 1520-5010 .- 0893-228X. ; 27:10, s. 1860-70
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Tidskriftsartikel (refereegranskat)abstract
- Allylic alcohols, such as geraniol 1, are easily oxidized by varying mechanisms, including the formation of both 2,3-epoxides and/or aldehydes. These epoxides, aldehydes, and epoxy-aldehydes can be interconverted to each other, and the reactivity of them all must be considered when considering the sensitization potential of the parent allylic alcohol. An in-depth study of the possible metabolites and autoxidation products of allylic alcohols is described, covering the formation, interconversion, reactivity, and sensitizing potential thereof, using a combination of in vivo, in vitro, in chemico, and in silico methods. This multimodal study, using the integration of diverse techniques to investigate the sensitization potential of a molecule, allows the identification of potential candidate(s) for the true culprit(s) in allergic responses to allylic alcohols. Overall, the sensitization potential of the investigated epoxyalcohols and unsaturated alcohols was found to derive from metabolic oxidation to the more potent aldehyde where possible. Where this is less likely, the compound remains weakly or nonsensitizing. Metabolic activation of a double bond to form a nonconjugated, nonterminal epoxide moiety is not enough to turn a nonsensitizing alcohol into a sensitizer, as such epoxides have low reactivity and low sensitizing potency. In addition, even an allylic 2,3-epoxide moiety is not necessarily a potent sensitizer, as shown for 2, where formation of the epoxide weakens the sensitization potential.
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| 7. |
- Delaine, Tamara, 1981, et al.
(författare)
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Skin Sensitization of Epoxyaldehydes: Importance of Conjugation.
- 2013
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Ingår i: Chemical research in toxicology. - : American Chemical Society (ACS). - 1520-5010 .- 0893-228X. ; 26:5, s. 674-684
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Tidskriftsartikel (refereegranskat)abstract
- Structure-activity relationship (SAR) models are important tools for predicting the skin sensitization potential of new compounds without animal testing. In compounds possessing a structural alert (aldehyde) and an activation alert (double bond), it is important to consider bioactivation/autoxidation (e.g., epoxidation). In the present study, we have explored a series of aldehydes with regard to contact allergy. The chemical reactivity of these 6 aldehydes toward a model hexapeptide was investigated, and their skin sensitization potencies were evaluated using the local lymph node assay (LLNA). Overall, we observed a similar trend for the in vitro reactivity and the in vivo sensitization potency for the structural analogues in this study. The highly reactive conjugated aldehydes (α,β-unsaturated aldehydes and 2,3-epoxyaldehydes) are sensitizing moieties, while nonconjugated aldehydes and nonterminal aliphatic epoxides show low reactivity and low sensitization potency. Our data show the importance of not only double bond conjugation to aldehyde but also epoxide-aldehyde conjugation. The observations indicate that the formation of nonconjugated epoxides by bioactivation or autoxidation is not sufficient to significantly increase the sensitization potency of weakly sensitizing parent compounds.
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| 8. |
- Delaine, Tamara, 1981, et al.
(författare)
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Structure-Activity Relationship between the in Vivo Skin Sensitizing Potency of Analogues of Phenyl Glycidyl Ether and the Induction of Nrf2-Dependent Luciferase Activity in the KeratinoSens in Vitro Assay.
- 2011
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Ingår i: Chemical research in toxicology. - : American Chemical Society (ACS). - 1520-5010 .- 0893-228X. ; 24:8, s. 1312-8
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Tidskriftsartikel (refereegranskat)abstract
- Because of regulatory constraints and ethical considerations, research on alternatives to animal testing to predict the skin sensitization potential of novel chemicals has become a high priority. Ideally, these alternatives should not only predict the hazard of novel chemicals but also rate the potency of skin sensitizers. Currently, no alternative method gives reliable potency estimations for a wide range of chemicals in differing structural classes. Performing potency estimations within specific structural classes has thus been proposed. Detailed structure-activity studies for the in vivo sensitization capacity of a series of analogues of phenyl glycidyl ether (PGE) were recently published. These studies are part of an investigation regarding the allergenic activity of epoxy-resin monomers. Here we report data on the same chemicals in the KeratinoSens in vitro assay, which is based on a stable transgenic keratinocyte cell line with a luciferase gene under the control of an antioxidant response element. A strong correlation between the EC3 values in the local lymph node assay (LLNA) and both the luciferase-inducing concentrations and the cytotoxicity in the cell-based assay was established for six analogues of PGE. This correlation allowed the potency in the LLNA of two novel structurally closely related derivatives to be predicted by read-across with errors of 1.4- and 2.6-fold. However, the LLNA EC3 values of two structurally different bifunctional monomers were overpredicted on the basis of this data set, indicating that accurate potency estimation by read-across based on in vitro data might be restricted to a relatively narrow applicability domain.
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| 9. |
- Dyrager, Christine, 1975, et al.
(författare)
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Inhibitors and promoters of tubulin polymerization : Synthesis and biological evaluation of chalcones and related dienones as potential anticancer agents
- 2011
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Ingår i: Bioorganic & Medicinal Chemistry. - : Elsevier BV. - 0968-0896 .- 1464-3391. ; 19:8, s. 2659-2665
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Tidskriftsartikel (refereegranskat)abstract
- A series of dihalogenated chalcones and structurally related dienones were synthesized and evaluated for their antiproliferative activity in 10 different cancer cell lines and for their effect on microtubule assembly. All compounds showed cytotoxic activity, with IC50 values in the 5-280 mu M range depending on the chalcone structure and the cell line. Five of the compounds were found to be tubulin polymerization inhibitors. In contrast, one of the compounds was found to stabilize tubulin to the same extent as the anticancer drug docetaxel. Molecular modeling suggested that the tubulin inhibitors bind to the colchicine binding site of beta-tubulin while the novel tubulin stabilization agent seems to interact with the paclitaxel binding site.
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| 10. |
- Fridén-Saxin, Maria, 1979, et al.
(författare)
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Proline-mediated formation of novel chroman-4-one tetrahydropyrimidines
- 2012
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Ingår i: Tetrahedron. - : Elsevier BV. - 0040-4020. ; 68:35, s. 7035-7040
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Tidskriftsartikel (refereegranskat)abstract
- Novel tricyclic N-benzylated chroman-4-one tetrahydropyrimidine derivatives have been prepared through a multi-component reaction between various 2-substituted chroman-4-one derivatives, N-methylenebenzylamine and a catalytic amount of proline under mild reaction conditions. The tricyclic structure of 1a was determined by NMR spectroscopy and confirmed by X-ray crystallography. An additional product, 2a, was isolated from the reaction mixture and its structure and conformation were determined by a combination of theoretical (Monte Carlo conformational search) and NMR-based (NOE and (3)J(HH) couplings) conformational analysis. The NMR analysis revealed one preferred geometry for 1a and 2a in CHCl3 solution. (C) 2012 Elsevier Ltd. All rights reserved.
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| 11. |
- Fridén-Saxin, Maria, 1979, et al.
(författare)
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Synthesis and Evaluation of Substituted Chroman-4-one and Chromone Derivatives as Sirtuin 2-Selective Inhibitors
- 2012
-
Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 55:16, s. 7104-7113
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Tidskriftsartikel (refereegranskat)abstract
- A series of substituted chromone/chroman-4-one derivatives has been synthesized and evaluated as novel inhibitors of SIRT2, an enzyme involved in aging-related diseases, e.g., neurodegenerative disorders. The analogues were efficiently synthesized in a one-step procedure including a base-mediated aldol condensation using microwave irradiation. The most potent compounds, with inhibitory concentrations in the low micromolar range, were substituted in the 2-, 6-, and 8-positions. Larger, electron-withdrawing substituents in the 6- and 8-positions were favorable. The most potent inhibitor of SIRT2 was 6,8-dibromo-2-pentylchroman-4-one with an IC50 of 1.5 mu M. The synthesized compounds show high selectivity toward SIRT2 over SIRT1 and SIRT3 and represent an important starting point for the development of novel SIRT2 inhibitors.
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| 12. |
- Garg, Gaurav, et al.
(författare)
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Variation in the MC4R Gene Is Associated with Bone Phenotypes in Elderly Swedish Women.
- 2014
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:2
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Tidskriftsartikel (refereegranskat)abstract
- Osteoporosis is characterized by reduced bone mineral density (BMD) and increased fracture risk. Fat mass is a determinant of bone strength and both phenotypes have a strong genetic component. In this study, we examined the association between obesity associated polymorphisms (SNPs) with body composition, BMD, Ultrasound (QUS), fracture and biomarkers (Homocysteine (Hcy), folate, Vitamin D and Vitamin B12) for obesity and osteoporosis. Five common variants: rs17782313 and rs1770633 (melanocortin 4 receptor (MC4R); rs7566605 (insulin induced gene 2 (INSIG2); rs9939609 and rs1121980 (fat mass and obesity associated (FTO) were genotyped in 2 cohorts of Swedish women: PEAK-25 (age 25, n = 1061) and OPRA (age 75, n = 1044). Body mass index (BMI), total body fat and lean mass were strongly positively correlated with QUS and BMD in both cohorts (r(2) = 0.2-0.6). MC4R rs17782313 was associated with QUS in the OPRA cohort and individuals with the minor C-allele had higher values compared to T-allele homozygotes (TT vs. CT vs.
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| 13. |
- Lagerholm, Sofia, et al.
(författare)
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Genetic loci for bone architecture determined by three-dimensional CT in crosses with the diabetic GK rat.
- 2010
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Ingår i: Bone. - : Elsevier BV. - 1873-2763 .- 8756-3282. ; 47, s. 1039-1047
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Tidskriftsartikel (refereegranskat)abstract
- The F344 rat carries alleles contributing to bone fragility while the GK rat spontaneously develops type-2 diabetes. These characteristics make F344xGK crosses well suited for the identification of genes related to bone size and allow for future investigation on the association with type-2 diabetes. The aim of this study was to identify quantitative trait loci (QTLs) for bone size phenotypes measured by a new application of three-dimensional computed tomography (3DCT) and to investigate the effects of sex- and reciprocal cross. Tibia from male and female GK and F344 rats, representing the parental, F1 and F2 generations, were examined with 3DCT and analyzed for: total and cortical volumetric BMD, straight and curved length, peri- and endosteal area at mid-shaft. F2 progeny (108 male and 98 female) were genotyped with 192 genome-wide microsatellite markers (average distance 10cM). Sex- and reciprocal cross-separated QTL analyses were performed for the identification of QTLs linked to 3DCT phenotypes and true interactions were confirmed by likelihood ratio analysis in all F2 animals. Several genome-wide significant QTLs were found in the sex- and reciprocal cross-separated progeny on chromosomes (chr) 1, 3, 4, 9, 10, 14, and 17. Overlapping QTLs for both males and females in the (GKxF344)F2 progeny were located on chr 1 (39-67cM). This region confirms previously reported pQCT QTLs and overlaps loci for fasting glucose. Sex separated linkage analysis confirmed a male specific QTL on chr 9 (67-82cM) for endosteal area at the fibula site. Analyses separating the F2 population both by sex and reciprocal cross identified cross specific QTLs on chr 14 (males) and chr 3 and 4 (females). Two loci, chr 4 and 6, are unique to 3DCT and separate from pQCT generated loci. The 3DCT method was highly reproducible and provided high precision measurements of bone size in the rat enabling identification of new sex- and cross-specific loci. The QTLs on chr 1 indicate potential genetic association between bone-related phenotypes and traits affecting type-2 diabetes. The results illustrate the complexity of the genetic architecture of bone size phenotypes and demonstrate the importance of complementary methods for bone analysis.
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| 14. |
- Lagerholm, Sofia, et al.
(författare)
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Identification of Candidate Gene Regions in the Rat by Co-Localization of QTLs for Bone Density, Size, Structure and Strength.
- 2011
-
Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:7
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Tidskriftsartikel (refereegranskat)abstract
- Susceptibility to osteoporotic fracture is influenced by genetic factors that can be dissected by whole-genome linkage analysis in experimental animal crosses. The aim of this study was to characterize quantitative trait loci (QTLs) for biomechanical and two-dimensional dual-energy X-ray absorptiometry (DXA) phenotypes in reciprocal F2 crosses between diabetic GK and normo-glycemic F344 rat strains and to identify possible co-localization with previously reported QTLs for bone size and structure. The biomechanical measurements of rat tibia included ultimate force, stiffness and work to failure while DXA was used to characterize tibial area, bone mineral content (BMC) and areal bone mineral density (aBMD). F2 progeny (108 males, 98 females) were genotyped with 192 genome-wide markers followed by sex- and reciprocal cross-separated whole-genome QTL analyses. Significant QTLs were identified on chromosome 8 (tibial area; logarithm of odds (LOD) = 4.7 and BMC; LOD = 4.1) in males and on chromosome 1 (stiffness; LOD = 5.5) in females. No QTLs showed significant sex-specific interactions. In contrast, significant cross-specific interactions were identified on chromosome 2 (aBMD; LOD = 4.7) and chromosome 6 (BMC; LOD = 4.8) for males carrying F344mtDNA, and on chromosome 15 (ultimate force; LOD = 3.9) for males carrying GKmtDNA, confirming the effect of reciprocal cross on osteoporosis-related phenotypes. By combining identified QTLs for biomechanical-, size- and qualitative phenotypes (pQCT and 3D CT) from the same population, overlapping regions were detected on chromosomes 1, 3, 4, 6, 8 and 10. These are strong candidate regions in the search for genetic risk factors for osteoporosis.
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| 15. |
- Lehmann, Fredrik, 1976, et al.
(författare)
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Optimization of isochromanone based urotensin II receptor agonists.
- 2010
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Ingår i: Bioorganic & medicinal chemistry. - : Elsevier BV. - 1464-3391 .- 0968-0896. ; 18:13, s. 4844-4854
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Tidskriftsartikel (refereegranskat)abstract
- A series of novel isochromanone based urotensin II receptor agonists have been synthesized and evaluated for their activity using a functional cell based assay (R-SAT). Several potent and efficacious derivatives were identified with 3-(3,4-dichlorophenyl)-6,7-dimethyl-3-(2-dimethylaminoethyl)isochroman-1-one (28) being the most potent compound showing an EC(50)-value of 51nM, thereby being the most potent compound so far within the isochromanone series. In addition, two other heterocyclic systems (isochromanes and tetrahydroisoquinolinones) were investigated and these derivatives were found to be both potent and efficacious. The activity of the isochromane derivatives implies that the carbonyl group of the isochromanone is not necessary for activity. Furthermore it was found that the geometry of the heterocycles was more important for receptor interaction than the composition of the heteroatoms present.
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| 16. |
- Malo, Marcus, et al.
(författare)
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Development of 7TM receptor-ligand complex models using ligand-biased, semi-empirical helix-bundle repacking in torsion space: application to the agonist interaction of the human dopamine D-2 receptor
- 2013
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Ingår i: Journal of Computer-Aided Molecular Design. - : Springer Science and Business Media LLC. - 0920-654X .- 1573-4951. ; 27:3, s. 277-291
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Tidskriftsartikel (refereegranskat)abstract
- Prediction of 3D structures of membrane proteins, and of G-protein coupled receptors (GPCRs) in particular, is motivated by their importance in biological systems and the difficulties associated with experimental structure determination. In the present study, a novel method for the prediction of 3D structures of the membrane-embedded region of helical membrane proteins is presented. A large pool of candidate models are produced by repacking of the helices of a homology model using Monte Carlo sampling in torsion space, followed by ranking based on their geometric and ligand-binding properties. The trajectory is directed by weak initial restraints to orient helices towards the original model to improve computation efficiency, and by a ligand to guide the receptor towards a chosen conformational state. The method was validated by construction of the β1 adrenergic receptor model in complex with (S)-cyanopindolol using bovine rhodopsin as template. In addition, models of the dopamine D2 receptor were produced with the selective and rigid agonist (R)-N-propylapomorphine ((R)-NPA) present. A second quality assessment was implemented by evaluating the results from docking of a library of 29 ligands with known activity, which further discriminated between receptor models. Agonist binding and recognition by the dopamine D2 receptor is interpreted using the 3D structure model resulting from the approach. This method has a potential for modeling of all types of helical transmembrane proteins for which a structural template with sequence homology sufficient for homology modeling is not available or is in an incorrect conformational state, but for which sufficient empirical information is accessible.
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| 17. |
- 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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| 18. |
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| 19. |
- 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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| 20. |
- Meinander, K., et al.
(författare)
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Pseudopeptides with a centrally positioned alkene-based disulphide bridge mimetic stimulate kallikrein-related peptidase 3 activity
- 2013
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Ingår i: Medchemcomm. - : Royal Society of Chemistry (RSC). - 2040-2503 .- 2040-2511. ; 4:3, s. 549-553
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Tidskriftsartikel (refereegranskat)abstract
- Pseudopeptides based on the kallikrein-related peptidase 3 (KLK3) activating bicyclic peptide “C-4” comprising hydrocarbon-based disulphide bridge mimetics have been synthesized. After investigating different synthetic approaches, the pseudopeptides were successfully cyclized from two L-allylglycine side chains via an alkene ring-closing metathesis reaction during the peptide synthesis. The alkene-linker was formed in a 1 : 1 E/Z isomer ratio. The resulting pseudopeptides were almost as potent as the parent peptide, increasing the activity of KLK3 over four-fold at 200 μg ml−1 (130–140 μM) concentrations.
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| 21. |
- Niklasson, Ida B, 1982, et al.
(författare)
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Bioactivation of Cinnamic Alcohol Forms Several Strong Skin Sensitizers
- 2014
-
Ingår i: Chemical Research in Toxicology. - : American Chemical Society (ACS). - 0893-228X .- 1520-5010. ; 27:4, s. 568-575
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Tidskriftsartikel (refereegranskat)abstract
- Cinnamic alcohol is a frequent contact allergen, causing allergic contact dermatitis (ACD) in a substantial number of individuals sensitized from contacts with fragrances. Hence, cinnamic alcohol is one of the constituents in fragrance mix I (FM I) used for screening contact allergy in dermatitis patients. Cinnamic alcohol lacks structural alerts for protein reactivity and must therefore be activated by either air oxidation or bioactivation to be able to act as a sensitizer. In the present study, we explored the bioactivation of cinnamic alcohol using human liver microsomes (HLM), and the potential pathways for these reactions were modeled by in silico (DFT) techniques. Subsequently, the reactivity of cinnamic alcohol and its metabolites toward a model hexapeptide were investigated. In addition to cinnamic aldehyde and cinnamic acid, two highly sensitizing epoiddes previously unobserved in studies of bioactivation were detected in the incubations with HLMs. Formation of epoxy cinnamic aldehyde was shown (both by the liver microsomal experiments, in which no depletion of epoxy cinnamic alcohol was observed after initial formation, and by the very high activation energy found for the oxidation thereof by calculations) to proceed via cinnamic aldehyde and not epoxy cinnamic alcohol.
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| 22. |
- Niklasson, Ida B, 1982, et al.
(författare)
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Cinnamyl alcohol oxidizes rapidly upon air exposure
- 2013
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Ingår i: Contact Dermatitis. - : Wiley. - 0105-1873 .- 1600-0536. ; 68:3, s. 129-138
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Tidskriftsartikel (refereegranskat)abstract
- Background. Cinnamyl alcohol and cinnamal are frequent fragrance contact allergens. Both are included in the European baseline fragrance mix I, which is used for screening of contact allergy in dermatitis patients. Objectives. The aim of this study was to investigate the autoxidation of cinnamyl alcoholandtoidentifytheoxidationproductsformedonairexposure.Wealsowantedto evaluate the effect of autoxidation on the sensitization potency of cinnamyl alcohol. Methods. Samples of commercially available cinnamyl alcohol with and without purificationwereexposedtoair,andtheautoxidationwasfollowedbychemicalanalysis. Theanalysiswasperformedwithmassspectrometry(LC/MS/MS).Sensitizationpotencies ofcompoundsweredeterminedwiththemurinelocallymphnodeassay(LLNA)inmice. Results. Chemical analysis showed that the concentration of cinnamyl alcohol in the air-exposed samples decreased rapidly over time, and that autoxidation products were formed. Cinnamal, epoxy cinnamyl alcohol and cinnamic acid were identified as oxidation products. According to our study, cinnamal and epoxy cinnamyl alcohol were thefirstautoxidation productsformed. Theepoxy cinnamyl alcohol wasshowntobethe oxidation product with the highest sensitization potency. The analysis of our samples of commercially available cinnamyl alcohol showed that there was already a content of 1.5% cinnamal at the start of the autoxidation experiments. Conclusion. Cinnamylalcoholreadilyautoxidizesuponairexposure,andformsstrong sensitizers as determined by the LLNA. Cinnamal was formed in the largest amounts, showingthatcinnamalisnotonlyformedviabioactivation,ashaspreviouslybeenshown. A highly sensitizing epoxide was also identified and quantified in the oxidation mixture.
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| 23. |
- Niklasson, Ida B, 1982, et al.
(författare)
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Impact of a Heteroatom in a Structure-Activity Relationship Study on Analogues of Phenyl Glycidyl Ether (PGE) from Epoxy Resin Systems.
- 2011
-
Ingår i: Chemical research in toxicology. - : American Chemical Society (ACS). - 1520-5010 .- 0893-228X. ; 24:4, s. 542-8
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Tidskriftsartikel (refereegranskat)abstract
- Epoxy resins are among the most common causes of occupational contact dermatitis. They are normally used in so-called epoxy resin systems (ERS). These commercial products are combinations of epoxy resins, curing agents, modifiers, and reactive diluents. The most frequently used resins are diglycidyl ethers based on bisphenol A (DGEBA) and bisphenol F (DGEBF). In this study, we have investigated the contact allergenic properties of a series of analogues to the reactive diluent phenyl glycidyl ether (PGE), all with similar basic structures but with varying heteroatoms or with no heteroatom present. The chemical reactivity of the compounds in the test series toward the hexapeptide H-Pro-His-Cys-Lys-Arg-Met-OH was investigated. All epoxides were shown to bind covalently to both cysteine and proline residues. The percent depletion of nonreacted peptide was also studied resulting in ca. 60% depletion when using either PGE, phenyl 2,3-epoxypropyl sulfide (2), or N-(2,3-epoxypropyl)aniline (3), and only 15% when using 1,2-epoxy-4-phenylbutane (4) at the same time point. The skin sensitization potencies of the epoxides using the murine local lymph node assay (LLNA) were evaluated in relation to the observed physicochemical and reactivity properties. To enable determination of statistical significance between structurally closely related compounds, a nonpooled LLNA was performed. It was found that all investigated compounds containing a heteroatom in the α-position to the epoxide were strong sensitizers, congruent with the reactivity data, indicating that the impact of a heteroatom is crucial for the sensitizing capacity for this type of epoxides.
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| 24. |
- Nystedt, Björn, et al.
(författare)
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The Norway spruce genome sequence and conifer genome evolution
- 2013
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Ingår i: Nature. - : Nature Publishing Group. - 0028-0836 .- 1476-4687. ; 497:7451, s. 579-584
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Tidskriftsartikel (refereegranskat)abstract
- Conifers have dominated forests for more than 200 million years and are of huge ecological and economic importance. Here we present the draft assembly of the 20-gigabase genome of Norway spruce (Picea abies), the first available for any gymnosperm. The number of well-supported genes (28,354) is similar to the >100 times smaller genome of Arabidopsis thaliana, and there is no evidence of a recent whole-genome duplication in the gymnosperm lineage. Instead, the large genome size seems to result from the slow and steady accumulation of a diverse set of long-terminal repeat transposable elements, possibly owing to the lack of an efficient elimination mechanism. Comparative sequencing of Pinus sylvestris, Abies sibirica, Juniperus communis, Taxus baccata and Gnetum gnemon reveals that the transposable element diversity is shared among extant conifers. Expression of 24-nucleotide small RNAs, previously implicated in transposable element silencing, is tissue-specific and much lower than in other plants. We further identify numerous long (>10,000 base pairs) introns, gene-like fragments, uncharacterized long non-coding RNAs and short RNAs. This opens up new genomic avenues for conifer forestry and breeding.
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| 25. |
- O'Boyle, Niamh M, et al.
(författare)
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Analogues of the epoxy resin monomer diglycidyl ether of Bisphenol F: effects on contact allergenic potency and cytotoxicity
- 2012
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Ingår i: Chemical Research in Toxicology. - : American Chemical Society (ACS). - 0893-228X .- 1520-5010. ; 25:11, s. 2469-2478
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Tidskriftsartikel (refereegranskat)abstract
- Diglycidyl ethers of bisphenol A (DGEBA) and bisphenol F (DGEBF) are widely used as components in epoxy resin thermosetting products. They are known to cause occupational and nonoccupational allergic contact dermatitis. The aim of this study is to investigate analogues of DGEBF with regard to contact allergy and cytotoxicity. A comprehensive knowledge of the structural features that contribute to the allergenic and cytotoxic effects of DGEBF will guide the development of future novel epoxy resin systems with reduced health hazards for those coming into contact with them. It was found that the allergenic effects of DGEBF were dependent on its terminal epoxide groups. In contrast, it was found that the cytotoxicity in monolayer cell culture was dependent not only on the presence of epoxide groups but also on other structural features.
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| 26. |
- O'Boyle, Niamh M, et al.
(författare)
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Epoxy Resin Monomers with Reduced Skin Sensitizing Potency
- 2014
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Ingår i: Chemical Research in Toxicology. - : American Chemical Society (ACS). - 0893-228X .- 1520-5010. ; 27:6, s. 1002-1010
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Tidskriftsartikel (refereegranskat)abstract
- Epoxy resin monomers (ERMs), especially diglycidyl ethers of bisphenol A and F (DGEBA and DGEBF), are extensively used as building blocks for thermosetting polymers. However, they are known to commonly cause skin allergy. This research describes a number of alternative ERMs, designed with the aim of reducing the skin sensitizing potency while maintaining the ability to form thermosetting polymers. The compounds were designed, synthesized, and assessed for sensitizing potency using the in vivo murine local lymph node assay (LLNA). All six epoxy resin monomers had decreased sensitizing potencies compared to those of DGEBA and DGEBF. With respect to the LLNA EC3 value, the best of the alternative monomers had a value approximately 2.5 times higher than those of DGEBA and DGEBF. The diepoxides were reacted with triethylenetetramine, and the polymers formed were tested for technical applicability using thermogravimetric analysis and differential scanning calorimetry. Four out of the six alternative ERMs gave polymers with a thermal stability comparable to that obtained with DGEBA and DGEBF. The use of improved epoxy resin monomers with less skin sensitizing effects is a direct way to tackle the problem of contact allergy to epoxy resin systems, particularly in occupational settings, resulting in a reduction in the incidence of allergic contact dermatitis.
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| 27. |
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| 28. |
- Seifert, Tina, 1985, et al.
(författare)
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Chroman-4-one- and Chromone-based Sirtuin 2 Inhibitors with Antiproliferative Properties in Cancer Cells
- 2014
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 57:23, s. 9870-9888
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Tidskriftsartikel (refereegranskat)abstract
- Sirtuins (SIRTs) catalyze the NAD+-dependent deacetylation of Nε-acetyl lysines on various protein substrates. SIRTs are interesting drug targets as they are considered to be related to important pathologies such as inflammation and aging-associated diseases. We have previously shown that chroman-4-ones act as potent and selective inhibitors of SIRT2. Herein we report novel chroman-4-one and chromone-based SIRT2 inhibitors containing various heterofunctionalities to improve pharmacokinetic properties. The compounds retained both high SIRT2 selectivity and potent inhibitory activity. Two compounds were tested for their antiproliferative effects in breast cancer (MCF-7) and lung carcinoma (A549) cell lines. Both compounds showed antiproliferative effects correlating with their SIRT2 inhibition potency. They also increased the acetylation level of α-tubulin, indicating that SIRT2 is likely to be the target in cancer cells. A binding mode of the inhibitors that is consistent with the SAR data was proposed based on a homology model of SIRT2.
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| 29. |
- Tadd, AC, et al.
(författare)
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Synthesis of Orthogonally Protected Disulfide Bridge Mimetics
- 2011
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Ingår i: Journal of organic chemistry. - 0022-3263. ; 76:2, s. 673-675
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Tidskriftsartikel (refereegranskat)abstract
- Concise routes to four orthogonally protected, enantiopure disulfide bridge mimetics are reported. These four dicarba analogues possess an alkyne, an (E)-alkene, a (Z)-alkene, and an alkane as substitutes for the disulfide bridge. Selective deprotection of one of these mimetics is also illustrated.
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