| 1. |
- Gustafsson, Sofia S., et al.
(författare)
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Quantification of interactions between drug leads and serum proteins by use of "binding efficiency"
- 2011
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Ingår i: Analytical Biochemistry. - : Elsevier BV. - 0003-2697 .- 1096-0309. ; 409:2, s. 163-175
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Tidskriftsartikel (refereegranskat)abstract
- To develop efficient and reliable methods for prediction of serum protein binding of drug leads, the kinetic characteristics for the interactions between selected compounds and human serum albumin and α(1)-acid glycoprotein have been explored using a surface plasmon resonance biosensor. Conventional methods for quantification of interactions (i.e., using rate constants or affinities determined on the basis of a reasonable mechanistic model) were applicable for only a few of the compounds. The affinity of a primary interaction and the contribution of lower affinity secondary interactions could be estimated for some compounds, but the affinity of many compounds could not be quantified by either of these methods. To have a quantification method that could be used for all compounds, independent of affinity and complexity of interaction mechanisms, the concept of "binding efficiency," analogous to "catalytic efficiency" used for enzymes, was developed. It allowed the quantification of the binding of compounds interacting with weak affinity and for which saturation is not reached within a concentration range where the compound is soluble or when the influence of interactions with secondary sites makes interpretations difficult. In addition, compounds with large fractional binding can be identified by this strategy and simply quantified relative to reference compounds. This approach will enable ranking and identification of structure-activity relationships of compounds with respect to their serum protein binding profile.
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| 2. |
- Nilsson, Magnus, et al.
(författare)
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Discovery of 4 '-azido-2 '-deoxy-2 '-C-methyl cytidine and prodrugs thereof : A potent inhibitor of Hepatitis C virus replication
- 2012
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Ingår i: Bioorganic & Medicinal Chemistry Letters. - : Elsevier BV. - 0960-894X .- 1464-3405. ; 22:9, s. 3265-3268
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Tidskriftsartikel (refereegranskat)abstract
- 4'-Azido-2'-deoxy-2'-methylcytidine (14) is a potent nucleoside inhibitor of the HCV NS5B RNA-dependent RNA polymerase, displaying an EC50 value of 1.2 mu M and showing moderate in vivo bioavailability in rat (F = 14%). Here we describe the synthesis and biological evaluation of 4'-azido-2'-deoxy-2'-methylcytidine and prodrug derivatives thereof. (C) 2012 Elsevier Ltd. All rights reserved.
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| 3. |
- Nilsson, Magnus, et al.
(författare)
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Synthesis and SAR of potent inhibitors of the Hepatitis C virus NS3/4A protease : Exploration of P2 quinazoline substituents
- 2010
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Ingår i: Bioorganic & Medicinal Chemistry Letters. - : Elsevier BV. - 0960-894X .- 1464-3405. ; 20:14, s. 4004-4011
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Tidskriftsartikel (refereegranskat)abstract
- Novel NS3/4A protease inhibitors comprising quinazoline derivatives as P2 substituent were synthesized. High potency inhibitors displaying advantageous PK properties have been obtained through the optimization of quinazoline P2 substituents in three series exhibiting macrocyclic P2 cyclopentane dicarboxylic acid and P2 proline urea motifs. For the quinazoline moiety it was found that 8-methyl substitution in the P2 cyclopentane dicarboxylic acid series improved on the metabolic stability in human liver microsomes. By comparison, the proline urea series displayed advantageous Caco-2 permeability over the cyclopentane series. Pharmacokinetic properties in vivo were assessed in rat on selected compounds, where excellent exposure and liver-to-plasma ratios were demonstrated for a member of the 14-membered quinazoline substituted P2 proline urea series. (C) 2010 Elsevier Ltd. All rights reserved.
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| 4. |
- Sallam, Hatem, et al.
(författare)
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The effect of circadian rhythm on pharmacokinetics and metabolism of the Cdk inhibitor, roscovitine, in tumor mice model
- 2015
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Ingår i: Chronobiology International. - Abingdon, Oxfordshire, United Kingdom : Taylor & Francis. - 0742-0528 .- 1525-6073. ; 32:5, s. 608-614
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Tidskriftsartikel (refereegranskat)abstract
- Roscovitine is a selective Cdk-inhibitor that is under investigation in phase II clinical trials under several conditions, including chemotherapy. Tumor growth inhibition has been previously shown to be affected by the dosing time of roscovitine in a Glasgow osteosarcoma xenograft mouse model. In the current study, we examined the effect of dose timing on the pharmacokinetics, biodistribution and metabolism of this drug in different organs in B6D2F1 mice. The drug was orally administered at resting (ZT3) or activity time of the mice (ZT19) at a dose of 300 mg/kg. Plasma and organs were removed at serial time points (10, 20 and 30 min; 1, 2, 4, 6, 8, 12 and 24 h) after the administration. Roscovitine and its carboxylic metabolite concentrations were analyzed using HPLC-UV, and pharmacokinetic parameters were calculated in different organs. We found that systemic exposure to roscovitine was 38% higher when dosing at ZT3, and elimination half-life was double compared to when dosing at ZT19. Higher organ concentrations expressed as (organ/plasma) ratio were observed when dosing at ZT3 in the kidney (180%), adipose tissue (188%), testis (132%) and lungs (112%), while the liver exposure to roscovitine was 120% higher after dosing at ZT19. The metabolic ratio was approximately 23% higher at ZT19, while the intrinsic clearance (CLint) was approximately 67% higher at ZT19, indicating faster and more efficient metabolism. These differences may be caused by circadian differences in the absorption, distribution, metabolism and excretion processes governing roscovitine disposition in the mice. In this article, we describe for the first time the chronobiodistribution of roscovitine in the mouse and the contribution of the dosing time to the variability of its metabolism. Our results may help in designing better dosing schedules of roscovitine in clinical trials.
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| 5. |
- Sohlenius-Sternbeck, Anna-Karin, et al.
(författare)
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Evaluation of ADMET Predictor in Early Discovery Drug Metabolism and Pharmacokinetics Project Work
- 2022
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Ingår i: Drug Metabolism And Disposition. - : American Society for Pharmacology and Experimental Therapy. - 0090-9556 .- 1521-009X. ; 50:2, s. 95-104
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Tidskriftsartikel (refereegranskat)abstract
- A dataset consisting of measured values for LogD, solubility, metabolic stability in human liver microsomes (HLMs), and Caco-2 permeability was used to evaluate the prediction models for lipophilicity (S+LogD), water solubility (S+Sw_pH), metabolic stability in HLM (CYP_HLM_Clint), intestinal permeability (S+Peff), and P-glycoprotein (P-gp) substrate identification (P-gp substrate) in the software ADMET Predictor (AP) from Simulations Plus. The dataset consisted of a total of 4, 794 compounds, with at least data from metabolic stability determinations in HLM, from multiple discovery projects at Medivir. Our evaluation shows that the global AP models can be used for categorization of high and low values based on predicted results for metabolic stability in HLM and intestinal permeability, and to give good predictions of LogD (R25 0.79), guiding the synthesis of new compounds and for prioritizing in vitro ADME experiments. The model seems to overpredict solubility for the Medivir compounds, however. We also used the in-house datasets to build local models for LogD, solubility, metabolic stability, and permeability by using artificial neural network (ANN) models in the optional Modeler module of AP. Predictions of the test sets were performed with both the global and the local models, and the R2 values for linear regression for predicted versus measured HLM in vitro intrinsic clearance (CLint) based on logarithmic data were 0.72 for the in-house model and 0.53 for the AP model. The improved predictions with the local models are likely explained both by the specific chemical space of the Medivir dataset and laboratory-specific assay conditions for parameters that require biologic assay systems. .
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