16 results on '"Chandrasena, Gamini"'
Search Results
2. Fused thiazolyl alkynes as potent mGlu5 receptor positive allosteric modulators.
- Author
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Packiarajan M, Grenon M, Zorn S, Hopper AT, White AD, Chandrasena G, Pu X, Brodbeck RM, and Robichaud AJ
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- Allosteric Regulation, Amides chemical synthesis, Amides chemistry, Amides metabolism, Carbamates chemical synthesis, Carbamates chemistry, Carbamates metabolism, Humans, Protein Binding, Receptor, Metabotropic Glutamate 5 metabolism, Structure-Activity Relationship, Thiazoles chemical synthesis, Thiazoles metabolism, Alkynes chemistry, Receptor, Metabotropic Glutamate 5 chemistry, Thiazoles chemistry
- Abstract
A new series of potent fused thiazole mGlu5 receptor positive allosteric modulators (PAMs) (10, 11 and 27-31) are disclosed and details of the SAR and optimization are described. Optimization of alkynyl thiazole 9 (Lu AF11205) led to the identification of potent fused thiazole analogs 10b, 27a, 28j and 31d. In general, substituted cycloalkyl, aryl and heteroaryl carboxamides, and carbamate analogs are mGlu5PAMs, whereas smaller alkyl carboxamide, sulfonamide and sulfamide analogs tend to be mGlu5 negative allosteric modulators (NAMs)., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
3. Discovery and structure-activity relationship of 1,3-cyclohexyl amide derivatives as novel mGluR5 negative allosteric modulators.
- Author
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Zhou H, Topiol SW, Grenon M, Jimenez HN, Uberti MA, Smith DG, Brodbeck RM, Chandrasena G, Pedersen H, Madsen JC, Doller D, and Li G
- Subjects
- Allosteric Regulation, Amides chemical synthesis, Amides pharmacokinetics, Animals, Cyclohexanes chemical synthesis, Cyclohexanes pharmacokinetics, HEK293 Cells, Humans, Mice, Models, Molecular, Molecular Conformation, Receptor, Metabotropic Glutamate 5 metabolism, Structure-Activity Relationship, Amides chemistry, Amides pharmacology, Cyclohexanes chemistry, Cyclohexanes pharmacology, Receptor, Metabotropic Glutamate 5 chemistry
- Abstract
A novel series of trans-1,3-cyclohexyl diamides was discovered and characterized as mGluR5 negative allosteric modulators (NAMs) lacking an alkyne moiety. Conformational constraint of one of the amide bonds in the diamide template led to a spirooxazoline template. A representative compound (24d) showed good in vitro potency, high CNS penetration and, upon subcutaneous dosing, demonstrated efficacy in the mouse marble burying test, generally used as indicative of potential anxiolytic activity., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
4. Azetidinyl oxadiazoles as potent mGluR5 positive allosteric modulators.
- Author
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Packiarajan M, Ferreira CG, Hong SP, White AD, Chandrasena G, Pu X, Brodbeck RM, and Robichaud AJ
- Subjects
- Animals, Azetidines metabolism, Azetidines pharmacokinetics, Humans, Oxadiazoles metabolism, Oxadiazoles pharmacokinetics, Rats, Receptor, Metabotropic Glutamate 5, Structure-Activity Relationship, Allosteric Regulation drug effects, Azetidines chemistry, Azetidines pharmacology, Oxadiazoles chemistry, Oxadiazoles pharmacology, Receptors, Metabotropic Glutamate metabolism
- Abstract
A novel series of aryl azetidinyl oxadiazoles are identified as mGluR5 positive allosteric modulators (PAMs) with improved physico-chemical properties. N-substituted cyclohexyl and exo-norbornyl carboxamides, and carbamate analogs of azetidines are moderate to potent mGluR5 PAMs. The aryl, lower alkyl carboxamides analogs and sulfonamide analogs of azetidines are moderate mGluR5 negative allosteric modulators (NAMs). In the aryl oxadiazole moiety, substituents such as fluoro, chloro and methyl are well tolerated at the meta position while para substituents led to either inactive compounds or NAMs. A tight pharmacophore and subtle 'PAM to NAM switching' with close analogs makes the optimization of the series extremely challenging., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
5. N-Aryl pyrrolidinonyl oxadiazoles as potent mGluR5 positive allosteric modulators.
- Author
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Packiarajan M, Mazza Ferreira CG, Hong SP, White AD, Chandrasena G, Pu X, Brodbeck RM, and Robichaud AJ
- Subjects
- Allosteric Regulation, Animals, Cell Line, Humans, Oxadiazoles pharmacokinetics, Pyrrolidines pharmacokinetics, Rats, Receptor, Metabotropic Glutamate 5, Structure-Activity Relationship, Oxadiazoles chemistry, Oxadiazoles pharmacology, Pyrrolidines chemistry, Pyrrolidines pharmacology, Receptors, Metabotropic Glutamate agonists, Receptors, Metabotropic Glutamate metabolism
- Abstract
A novel series of N-aryl pyrrolidinonyl oxadiazoles were identified as mGluR5 positive allosteric modulators (PAMs). Optimization of the initial lead compound 6a led to the identification of the 12c (-) enantiomer as a potent compound with acceptable in vitro clearance, CYP, hERG and PK properties. Para substituted N-aryl pyrrolidinonyl oxadiazoles are mGluR5 PAMs while the meta and ortho substituted N-aryl pyrrolidinonyl oxadiazoles are negative allosteric modulators (NAMs). Para fluoro substitution on the N-aryl group and meta chloro or methyl substituents on the aryl oxadiazole moiety are optimal for mGluR5 PAM efficacy. The existence of an exquisitely sensitive 'PAM to NAM switch' within this chemotype making it challenging for simultaneous optimization of potency and drug-like properties., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
6. Indolyl and dihydroindolyl N-glycinamides as potent and in vivo active NPY5 antagonists.
- Author
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Wu L, Lu K, Packiarajan M, Jubian V, Chandrasena G, Wolinsky TC, and Walker MW
- Subjects
- Amides pharmacokinetics, Amides pharmacology, Animals, Appetite Stimulants chemical synthesis, Appetite Stimulants pharmacokinetics, Appetite Stimulants pharmacology, Brain drug effects, Cell Line, Eating drug effects, Glycine pharmacokinetics, Glycine pharmacology, Humans, Indoles pharmacokinetics, Indoles pharmacology, Kinetics, Male, Molecular Structure, Permeability, Rats, Rats, Sprague-Dawley, Receptors, Neuropeptide Y agonists, Receptors, Neuropeptide Y chemistry, Structure-Activity Relationship, Amides chemical synthesis, Glycine analogs & derivatives, Glycine chemical synthesis, Indoles chemical synthesis, Receptors, Neuropeptide Y antagonists & inhibitors
- Abstract
A novel series of indolyl and dihydroindolyl glycinamides were identified as potent NPY5 antagonists with in vivo activity from screen hit 1. The dihydroindolyl glycinamide 10a significantly inhibits NPY5 agonist induced feeding at a dose of 0.1 mg/kg. The indolyl glycinamide 12c also inhibits NPY5 agonist induced feeding at a dose of 1 mg/kg. Both compounds 10a and 12c represent potential tools for further investigation into the biology of the NPY5 receptor., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
7. 5-(2'-Pyridyl)-2-aminothiazoles: alkyl amino sulfonamides and sulfamides as potent NPY(5) antagonists.
- Author
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Packiarajan M, Coate H, Desai M, Jimenez HN, Reinhard EJ, Jubian VJ, Marzabadi MR, Chandrasena G, Wolinski TC, Walker MW, and Andersen K
- Subjects
- Animals, Feeding Behavior drug effects, Humans, Injections, Intraventricular, Rats, Solubility, Sulfonamides administration & dosage, Sulfonamides chemistry, Receptors, Neuropeptide Y antagonists & inhibitors, Sulfonamides pharmacology
- Abstract
Synthesis, SAR and physico-chemical properties of an alkyl aminothiazole series 8 and 16 are described. 2-Pyridylaminothiazole based compounds such as 8c and 16a exhibit high affinity at the NPY(5) receptor with desirable cLogPs and solubilities. However, they also suffer from high in vitro and in vivo clearance. Compound 16a partially inhibits the feeding behavior elicited by i.c.v. injection of the selective NPY(5) agonist [cPP(1-7), NPY(19-23), Ala(31), Aib(32), Gln(34)]-human pancreatic polypeptide polypeptide (cPP)., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
8. N-Heteroaryl glycinamides and glycinamines as potent NPY5 antagonists.
- Author
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Wu L, Lu K, Desai M, Packiarajan M, Joshi A, Marzabadi MR, Jubian V, Andersen K, Chandrasena G, Boyle NJ, and Walker MW
- Subjects
- Amines blood, Amines chemistry, Animals, Dose-Response Relationship, Drug, Glycine blood, Glycine chemistry, Glycine pharmacology, Heterocyclic Compounds blood, Heterocyclic Compounds chemistry, Humans, Male, Molecular Structure, Rats, Rats, Sprague-Dawley, Stereoisomerism, Structure-Activity Relationship, Amines pharmacology, Glycine analogs & derivatives, Heterocyclic Compounds pharmacology, Receptors, Neuropeptide Y antagonists & inhibitors
- Abstract
Subtype specific ligands are needed to evaluate the therapeutic potential of modulating the brain's neuropeptide Y system. The benzothiazepine glycinamide 1a was identified as an NPY5 antagonist lead. While having acceptable solubility, the compound was found to suffer from high clearance and poor exposure. Optimization efforts are described targeting improvements in potency, microsomal stability, and PK properties. The low microsomal stability and poor PK properties were addressed through the optimization of the sulfonyl urea and replacement of the benzothiazepinone with other N-heteroaryl glycinamides. For example, the analogous benzoxazine glycinamide 2e has improvements in both affinity (human Y5 K(i) 4 nM vs 1a 27 nM) and microsomal stability (human CL(int) 2.5 L/min vs 1a 35L/min). However the brain penetration (B/P 43/430 nM at 10 mg/kg PO) remained an unresolved issue. Further optimization by decreasing the hydrogen bond donating properties and PSA provided potent and brain penetrant NPY5 antagonists such as 5f (human Y5 K(i) 9 nM, B/P 520/840 nM 10 mg/kg PO)., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
9. Strategies to lower the Pgp efflux liability in a series of potent indole azetidine MCHR1 antagonists.
- Author
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Lu K, Jiang Y, Chen B, Eldemenky EM, Ma G, Packiarajan M, Chandrasena G, White AD, Jones KA, Li B, and Hong SP
- Subjects
- ATP Binding Cassette Transporter, Subfamily B, Member 1 deficiency, Animals, Azetidines chemical synthesis, Azetidines chemistry, Hydrogen Bonding, Indoles chemical synthesis, Indoles chemistry, Mice, Mice, Knockout, Molecular Structure, Rats, Receptors, Somatostatin metabolism, Stereoisomerism, ATP Binding Cassette Transporter, Subfamily B, Member 1 metabolism, Azetidines pharmacology, Indoles pharmacology, Receptors, Somatostatin antagonists & inhibitors
- Abstract
A series of potent indolyl azetidine rMCHR1 antagonists were found to show poor CNS penetration due to Pgp efflux. We envisioned a strategy which included: lowering basicity; changing the conformational flexibility motif; and removal of a hydrogen bond donor, in an attempt to optimize this property while maintaining target receptor efficacy. This work resulted in mitigation of Pgp efflux, and led us to identify 1-dihydroindolyl azetidine derivatives with CNS penetration and excellent rMCHR1 binding affinity., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
10. Discovery of Lu AA33810: a highly selective and potent NPY5 antagonist with in vivo efficacy in a model of mood disorder.
- Author
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Packiarajan M, Marzabadi MR, Desai M, Lu Y, Noble SA, Wong WC, Jubian V, Chandrasena G, Wolinsky TD, Zhong H, Walker MW, Wiborg O, and Andersen K
- Subjects
- Animals, Benzothiepins chemical synthesis, Benzothiepins chemistry, Biological Availability, Disease Models, Animal, Dose-Response Relationship, Drug, Drug Evaluation, Preclinical, Mice, Molecular Structure, Mood Disorders metabolism, Rats, Stereoisomerism, Structure-Activity Relationship, Sulfonamides chemical synthesis, Sulfonamides chemistry, Benzothiepins pharmacology, Drug Discovery, Mood Disorders drug therapy, Receptors, Neuropeptide Y antagonists & inhibitors, Sulfonamides pharmacology
- Abstract
The structure-activity relationship of a series of tricyclic-sulfonamide compounds 11-32 culminating in the discovery of N-[trans-4-(4,5-dihydro-3,6-dithia-1-aza-benzo[e]azulen-2-ylamino)-cyclohexylmethyl]-methanesulfonamide (15, Lu AA33810) is reported. Compound 15 was identified as a selective and high affinity NPY5 antagonist with good oral bioavailability in mice (42%) and rats (92%). Dose dependent inhibition of feeding was observed after i.c.v. injection of the selective NPY5 agonist ([cPP(1-7),NPY(19-23),Ala(31),Aib(32),Gln(34)]-hPP). In addition, ip administration of Lu AA33810 (10 mg/kg) produced antidepressant-like effects in a rat model of chronic mild stress., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
11. Design and synthesis of 4-arylpiperidinyl amide and N-arylpiperdin-3-yl-cyclopropane carboxamide derivatives as novel melatonin receptor ligands.
- Author
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Li G, Zhou H, Jiang Y, Keim H, Topiol SW, Poda SB, Ren Y, Chandrasena G, and Doller D
- Subjects
- Amides chemical synthesis, Amides pharmacology, Animals, Cyclopropanes chemistry, Cyclopropanes pharmacology, Drug Design, Humans, Ligands, Microsomes metabolism, Piperidines chemistry, Piperidines pharmacology, Rats, Receptor, Melatonin, MT1 metabolism, Receptor, Melatonin, MT2 metabolism, Structure-Activity Relationship, Amides chemistry, Cyclopropanes chemical synthesis, Piperidines chemical synthesis, Receptor, Melatonin, MT1 agonists, Receptor, Melatonin, MT2 agonists
- Abstract
Two series of 4-arylpiperidinyl amide and N-arylpiperdin-3-yl-cyclopropane carboxamide derivatives exhibiting diverse functionality at rat MT(1) and MT(2) receptors are reported. Compounds 11f and 18b (MT(1)/MT(2) agonist) have human microsomal intrinsic clearance comparable to ramelteon., (Copyright © 2010 Elsevier Ltd. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
12. Identification and optimization of a novel series of [2.2.1]-oxabicyclo imide-based androgen receptor antagonists.
- Author
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Salvati ME, Balog A, Shan W, Rampulla R, Giese S, Mitt T, Furch JA, Vite GD, Attar RM, Jure-Kunkel M, Geng J, Rizzo CA, Gottardis MM, Krystek SR, Gougoutas J, Galella MA, Obermeier M, Fura A, and Chandrasena G
- Subjects
- Administration, Oral, Androgen Antagonists pharmacology, Anilides pharmacology, Animals, Bridged Bicyclo Compounds, Heterocyclic chemical synthesis, Bridged Bicyclo Compounds, Heterocyclic pharmacokinetics, Chromatography, High Pressure Liquid, Drug Design, Humans, Isoindoles chemical synthesis, Isoindoles pharmacokinetics, Male, Mice, Mice, Inbred BALB C, Models, Molecular, Molecular Structure, Nitriles pharmacology, Prostatic Neoplasms blood, Prostatic Neoplasms pathology, Protein Binding, Receptors, Androgen metabolism, Structure-Activity Relationship, Tosyl Compounds pharmacology, Tumor Cells, Cultured, Androgen Receptor Antagonists, Bridged Bicyclo Compounds, Heterocyclic pharmacology, Isoindoles pharmacology, Prostatic Neoplasms drug therapy
- Abstract
A novel series of [2.2.1]-oxabicyclo imide-based compounds were identified as potent antagonists of the androgen receptor. Molecular modeling and iterative drug design were applied to optimize this series. The lead compound [3aS-(3aalpha,4beta,5beta,7beta,7aalpha)]-4-(octahydro-5-hydroxy-4,7-dimethyl-1,3-dioxo-4,7-epoxy-2H-isoindol-2-yl)-2-iodobenzonitrile was shown to have potent in vivo efficacy after oral dosing in the CWR22 human prostate tumor xenograph model.
- Published
- 2008
- Full Text
- View/download PDF
13. Discovery of tertiary aminoacids as dual PPARalpha/gamma agonists-I.
- Author
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Devasthale PV, Chen S, Jeon Y, Qu F, Ryono DE, Wang W, Zhang H, Cheng L, Farrelly D, Golla R, Grover G, Ma Z, Moore L, Seethala R, Sun W, Doweyko AM, Chandrasena G, Sleph P, Hariharan N, and Cheng PT
- Subjects
- Amino Acids chemistry, Amino Acids pharmacology, Animals, Blood Glucose drug effects, Hypoglycemic Agents chemistry, Hypoglycemic Agents pharmacology, Hypolipidemic Agents chemistry, Hypolipidemic Agents pharmacology, Mice, Mice, Inbred Strains, Structure-Activity Relationship, Glycine analogs & derivatives, Glycine pharmacology, PPAR alpha agonists, PPAR gamma agonists
- Abstract
A novel series of potent dual agonists of PPARalpha and PPARgamma, the alkoxybenzylglycines, was identified and explored using a solution-phase library approach. The synthesis and structure-activity relationships of this series of dual PPARalpha/gamma agonists are described.
- Published
- 2007
- Full Text
- View/download PDF
14. Synthesis and biological activity of 5-aryl-4-(4-(5-methyl-1H-imidazol-4-yl)piperidin-1-yl)pyrimidine analogs as potent, highly selective, and orally bioavailable NHE-1 inhibitors.
- Author
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Atwal KS, O'Neil SV, Ahmad S, Doweyko L, Kirby M, Dorso CR, Chandrasena G, Chen BC, Zhao R, and Zahler R
- Subjects
- Administration, Oral, Animals, Biological Availability, Inhibitory Concentration 50, Molecular Structure, Piperidines chemical synthesis, Piperidines pharmacokinetics, Pyrimidines chemical synthesis, Pyrimidines pharmacokinetics, Rats, Sodium-Hydrogen Exchangers metabolism, Structure-Activity Relationship, Piperidines chemistry, Piperidines pharmacology, Pyrimidines chemistry, Pyrimidines pharmacology, Sodium-Hydrogen Exchangers antagonists & inhibitors
- Abstract
A series of potent inhibitors of the sodium hydrogen exchanger-1 (NHE-1) is described. Structure-activity relationships identified the 3-methyl-4-fluoro analog 9t as a highly potent (IC50 = 0.0065 microM) and selective (NHE-2/NHE-1=1400) non-acylguanidine NHE-1 inhibitor. Pharmacokinetic studies showed that compound 9t has an oral bioavailability of 52% and a plasma half life of 1.5 h in rats. Because of its promising potency, selectivity, and a good pharmacokinetic profile, compound 9t was selected for further studies.
- Published
- 2006
- Full Text
- View/download PDF
15. A 3D-QSAR model for CYP2D6 inhibition in the aryloxypropanolamine series.
- Author
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Vaz RJ, Nayeem A, Santone K, Chandrasena G, and Gavai AV
- Subjects
- Animals, Humans, Inhibitory Concentration 50, Models, Molecular, Propanolamines pharmacology, Substrate Specificity, Cytochrome P-450 CYP2D6 Inhibitors, Propanolamines chemistry, Quantitative Structure-Activity Relationship
- Abstract
A comparative molecular similarity index analysis (CoMSiA) has been performed for cytochrome P450 2D6 inhibition on a series of aryloxypropanolamines to determine the factors contributing to this activity. The model is in agreement with a CYP2D6 homology model constructed on the basis of the mammalian CYP2C5 crystal structure. The energy minimized conformations were generated using the systematic search methodology in Sybyl 6.7. The model not only elucidated the relationship between structure and biological activity but, more importantly, provided useful strategies to modulate CYP2D6 affinity in the aryloxypropanolamine series.
- Published
- 2005
- Full Text
- View/download PDF
16. Aminoimidazoles as bioisosteres of acylguanidines: novel, potent, selective and orally bioavailable inhibitors of the sodium hydrogen exchanger isoform-1.
- Author
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Ahmad S, Ngu K, Combs DW, Wu SC, Weinstein DS, Liu W, Chen BC, Chandrasena G, Dorso CR, Kirby M, and Atwal KS
- Subjects
- Administration, Oral, Biological Availability, Cation Transport Proteins metabolism, Cell Line, Guanidines chemistry, Guanidines pharmacokinetics, Humans, Imidazoles chemistry, Imidazoles pharmacokinetics, Membrane Proteins metabolism, Protein Isoforms antagonists & inhibitors, Protein Isoforms metabolism, Sodium-Hydrogen Exchanger 1, Sodium-Hydrogen Exchangers metabolism, Stereoisomerism, Cation Transport Proteins antagonists & inhibitors, Guanidines administration & dosage, Imidazoles administration & dosage, Membrane Proteins antagonists & inhibitors, Sodium-Hydrogen Exchangers antagonists & inhibitors
- Abstract
Inhibition of the sodium hydrogen exchanger isoform-1 (NHE-1) has been shown to limit damage to the myocardium under ischemic conditions in animals. While most known NHE-1 inhibitors are acylguanidines, this report describes the design and synthesis of a series of heterocyclic inhibitors of NHE-1 including aminoimidazoles with undiminished in vitro activity and oral bioavailability.
- Published
- 2004
- Full Text
- View/download PDF
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