Poly-Arginine Peptides R18 and R18D Improve Functional Outcomes After Endothelin-1-Induced Stroke in the Sprague Dawley Rat.

We have previously demonstrated that R18 and its d-enantiomer, R18D, are neuroprotective at 24 hours following intraluminal filament occlusion of the middle cerebral artery (MCAO) in the rat. This study examined R18 and R18D effectiveness in improving functional outcomes at up to 56 days poststroke following endothelin-1-induced MCAO. Peptides were administered intravenously at doses of 100, 300, or 1000 nmol/kg, 60 minutes after MCAO.

Bilateral ischaemic lesions of the medial prefrontal cortex are anxiogenic in the rat.

Objective: Stroke patients often suffer from delayed disturbances of mood and cognition. In rodents, the prefrontal cortex (PFC) is involved in both higher order cognition and emotion. Our objective was to determine if bilateral focal ischaemic lesions restricted to the medial prefrontal cortex (mPFC) could be used to model post-stroke anxiety and/or cognitive deficits.

Effects of endothelin-induced prefrontal cortical lesions on delay discounting in the rat.

Stroke is one of the most prominent causes of neurological disability, and the number of stroke cases worldwide is expected to grow due to increases in both average life span and population. As such, new methods for both acute treatment and poststroke rehabilitation will be increasingly necessary. Although a number of approaches to restoring motor function poststroke are in development, there are few methods to alleviate the cognitive deficits caused by this disease.

Prefrontal Ischemia in the Rat Leads to Secondary Damage and Inflammation in Remote Gray and White Matter Regions.

Secondary damage processes, such as inflammation and oxidative stress, can exacerbate an ischemic lesion and spread to adjacent brain regions. Yet, few studies investigate how regions remote from the infarct could also suffer from degeneration and inflammation in the aftermath of a stroke. To find out to what extent far-remote brain regions are affected after stroke, we used a bilateral endothelin-1-induced prefrontal infarct rat model.

Ischemic lesions localized to the medial prefrontal cortex produce selective deficits in measures of executive function in rats.

Ischemic stroke is one of the leading causes of neurological disability worldwide, and it has been estimated that about one quarter of stroke survivors experience some measurable long-term cognitive impairments. Many higher order cognitive deficits occur because of damage to the prefrontal cortex (PFC), which is one of the main areas of the brain responsible for executive functioning in mammals. Currently, there are few animal models that examine the effects of stroke on executive function.

Discovery of bicyclic pyrazoles as class III histone deacetylase SIRT1 and SIRT2 inhibitors.

A series of bicyclic pyrazole carboxamides was synthesized and tested for inhibitory activity against the class III deacetylase sirtuin enzymes. Moderate to low micromolar inhibitory activities were obtained against SIRT1 and SIRT2. These bicyclic pyrazole compounds represent a new class of sirtuin inhibitors with a preference for SIRT1 over SIRT2.

Identification of a novel series of potent RON receptor tyrosine kinase inhibitors.

A novel series of N-(3-fluoro-4-(2-substituted-thieno[3,2-b]pyridin-7-yloxy)phenyl)-1-phenyl-5-(trifluoromethyl)-1H-pyrazole-4-carboxamides targeting RON receptor tyrosine kinase was designed and synthesized. SAR study of the series allowed us to identify compounds possessing either inhibitory activity of RON kinase enzyme in the low nanomolar range with low residual activity against the closely related c-Met or potent dual inhibitory activity against RON and c-Met, with no significant activity against VEGFR2 in both cases.

N3-arylmalonamides: a new series of thieno[3,2-b]pyridine based inhibitors of c-Met and VEGFR2 tyrosine kinases.

A family of thieno[3,2-b]pyridine based small molecule inhibitors of c-Met and VEGFR2 were designed based on lead structure 2. These compounds were shown to have IC(50) values in the low nanomolar range in vitro and were efficacious in human tumor xenograft models in mice in vivo.

N-(4-(6,7-Disubstituted-quinolin-4-yloxy)-3-fluorophenyl)-2-oxo-3-phenylimidazolidine-1-carboxamides: a novel series of dual c-Met/VEGFR2 receptor tyrosine kinase inhibitors.

A series of N-(4-(6,7-disubstituted-quinolin-4-yloxy)-3-fluorophenyl)-2-oxo-3-phenylimidazolidine-1-carboxamides targeting c-Met and VEGFR2 tyrosine kinases was designed and synthesized. The compounds were potent against these two enzymes with IC(50) values in the low nanomolar range in vitro, possessed favorable pharmacokinetic profiles and showed high efficacy in vivo in several human tumor xenograft models in mice.

Diphenylmethylene hydroxamic acids as selective class IIa histone deacetylase inhibitors.

We have identified a series of diphenylmethylene hydroxamic acids as novel and selective HDAC class IIa inhibitors. The original hit, N-hydroxy-2,2-diphenylacetamide (6), has sub-micromolar class IIa HDAC inhibitory activity, while the rigidified oxygen analogue, N-hydroxy-9H-xanthene-9-carboxamide (13), is slightly more selective for HDAC7 with an IC(50) of 0.05muM.

Synthesis and evaluation of lysine derived sulfamides as histone deacetylase inhibitors.

We have recently reported on a novel class of histone deacetylase (HDAC) inhibitors bearing a sulfamide group as the zinc-binding unit. Herein, we report on the synthesis of sulfamide based inhibitors designed around a lysine scaffold and their structure-activity relationships against HDAC1 and HDAC6 isotypes as well as 293T cells. Our efforts led us to an improvement of the originally disclosed lysine-based sulfamide, 2a to compound 12h which has equal potency in enzyme and cell-based assays as well as enhanced metabolic stability and PK profile.

N-(3-fluoro-4-(2-arylthieno[3,2-b]pyridin-7-yloxy)phenyl)-2-oxo-3-phenylimidazolidine-1-carboxamides: a novel series of dual c-Met/VEGFR2 receptor tyrosine kinase inhibitors.

A series of N-(3-fluoro-4-(2-arylthieno[3,2-b]pyridin-7-yloxy)phenyl)-2-oxo-3-phenylimidazolidine-1-carboxamides targeting c-Met and VEGFR2 tyrosine kinases was designed and synthesized. The compounds were potent against these two enzymes with IC(50) values in the low nanomolar range in vitro, possessed favorable pharmacokinetic profiles and showed high efficacy in vivo in several human tumor xenograft models in mice.

N-Benzyl-1-heteroaryl-3-(trifluoromethyl)-1H-pyrazole-5-carboxamides as inhibitors of co-activator associated arginine methyltransferase 1 (CARM1).

A series of N-benzyl-1-heteroaryl-3-(trifluoromethyl)-1H-pyrazole-5-carboxamides targeting co-activator associated arginine methyltransferase 1 (CARM1) have been designed and synthesized. The potency of these inhibitors was influenced by the nature of the heteroaryl fragment with the thiophene analogues being superior to thiazole, pyridine, isoindoline and benzofuran based inhibitors.

Novel HDAC6 isoform selective chiral small molecule histone deacetylase inhibitors.

In an effort to identify HDAC isoform selective inhibitors, we designed and synthesized novel, chiral 3,4-dihydroquinoxalin-2(1H)-one and piperazine-2,5-dione aryl hydroxamates showing selectivity (up to 40-fold) for human HDAC6 over other class I/IIa HDACs. The observed selectivity and potency (IC(50) values 10-200 nM against HDAC6) is markedly dependent on the absolute configuration of the chiral moiety, and suggests new possibilities for use of chiral compounds in selective HDAC isoform inhibition.

Sulfamides as novel histone deacetylase inhibitors.

The sulfamide moiety has been utilized to design novel HDAC inhibitors. The potency and selectivity of these inhibitors were influenced both by the nature of the scaffold, and the capping group. Linear long-chain-based analogs were primarily HDAC6-selective, while analogs based on the lysine scaffold resulted in potent HDAC1 and HDAC6 inhibitors.

Efficient parallel synthesis of macrocyclic peptidomimetics.

A new method for solid phase parallel synthesis of chemically and conformationally diverse macrocyclic peptidomimetics is reported. A key feature of the method is access to broad chemical and conformational diversity. Synthesis and mechanistic studies on the macrocyclization step are reported.

Discovery of a novel and potent series of thieno[3,2-b]pyridine-based inhibitors of c-Met and VEGFR2 tyrosine kinases.

A series of thieno[3,2-b]pyridine-based inhibitors of c-Met and VEGFR2 tyrosine kinases is described. The compounds demonstrated potency with IC(50) values in the low nanomolar range in vitro while the lead compound also showed in vivo activity against various human tumor xenograft models in mice. Further exploration of this class of compounds is underway.

Potent macrocyclic antagonists to the motilin receptor presenting novel unnatural amino acids.

Novel, potent small molecule motilin receptor antagonists are described. These peptidomimetic macrocycles are composed of a tripeptide cyclized backbone-to-backbone with a nonpeptidic tether and bear new unnatural amino acids containing basic side chains.

Optimization and determination of the absolute configuration of a series of potent inhibitors of human papillomavirus type-11 E1-E2 protein-protein interaction: a combined medicinal chemistry, NMR and computational chemistry approach.

We have previously reported the discovery and initial SAR optimization of the first series of inhibitors of the human papillomavirus type-11 (HPV11) E1-E2 protein-protein interaction. These inhibitors featured an indandione system spiro-fused onto an all syn substituted tetrahydrofuran ring. In this paper, we report new SAR efforts which have led to the identification of the first low nanomolar inhibitor of the HPV11 E1-E2 protein-protein interaction.

Discovery of a new class of macrocyclic antagonists to the human motilin receptor.

A novel class of macrocyclic peptidomimetics was identified and optimized as potent antagonists to the human motilin receptor (hMOT-R). Well-defined structure-activity relationships allowed for rapid optimization of potency that eventually led to high affinity antagonists to hMOT-R. Potency and antagonist functional activity were confirmed both in functional and cell-based assays, as well as on isolated rabbit intestinal smooth muscle strips.

Novel 8-substituted dipyridodiazepinone inhibitors with a broad-spectrum of activity against HIV-1 strains resistant to non-nucleoside reverse transcriptase inhibitors.

A series of novel 8-substituted dipyridodiazepinone-based inhibitors were investigated for their antiviral activity against wild type human immunodeficiency virus (HIV-1) and the clinically prevalent K103N/Y181C mutant virus. Our efforts have resulted in a series of benzoic acid analogues that are potent inhibitors of HIV-1 replication against a panel of HIV-1 strains resistant to non-nucleoside reverse transcriptase inhibitors (NNRTIs). Furthermore, the combination of good antiviral potency, a broad spectrum of activity, and an excellent pharmacokinetic profile provides strong justification for the further development of compound (7) as a potential treatment for wild type and NNRTI-resistant HIV-1 infection.

Novel nevirapine-like inhibitors with improved activity against NNRTI-resistant HIV: 8-heteroarylthiomethyldipyridodiazepinone derivatives.

A series of 8-heteroarylthiomethyldipyridodiazepinone derivatives were prepared and evaluated for their antiviral profile against wild type virus and the important K103N/Y181C mutant as an indicator for broad activity. 2,6-Dimethylpyridine derivative 16 was found to have a good pharmacokinetic profile in spite of poor metabolic stability in rat liver microsomes.

A rational approach towards successful crystallization and crystal treatment of human cytomegalovirus protease and its inhibitor complex.

The crystallization and subsequent crystal treatment of both free human cytomegalovirus (hCMV) protease and its inhibitor complexes are reported. For free-enzyme crystals, diffraction was greatly improved by optimizing the crystallization conditions, raising the precipitant concentration in the reservoir and soaking the crystals in artificial mother liquors. Each of the six components in the final crystallization formula (16% PEG 4000, 0.

Synthesis and antiviral activity of monobactams inhibiting the human cytomegalovirus protease.

A series of monobactam inhibitors of HCMV (N(o)) protease bearing a heterocycle linked by a methylene group at C-4 is described. Inhibitors containing a heterocycle such as a 2-furyl, 2-thiophenyl, 4-methyl-2-tetrazole and 2-benzothiazole were found to be active in a plaque reduction assay. Furthermore, 2-benzothiazole derivatives were shown to inhibit the HCMV protease activity inside cells by using a cell transfection assay, indicating that their antiviral activity in the plaque reduction assay could be attributed to protease inhibition.

Potent beta-lactam inhibitors of human cytomegalovirus protease.

A series of novel monobactam inhibitors of human cytomegalovirus (HCMV) protease has been described that possess a heterocyclic thiomethyl side chain at C-4. Changes to the heterocycle did not significantly change the inhibitory activity of these compounds in an enzymatic assay, although improvements in solubility and cell culture activity were noted. A number of permutations between C-4 substitutions and N-1 derivatives led to the identification of several beta-lactams with antiviral activity in a plaque reduction assay.