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Selective Compounds (selective + compound)
Selected AbstractsA non-peptide radioiodinated high affinity melanocortin-4 receptor ligandJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 11 2003Felikss Mutulis Abstract 4-Cyclohexyl-4-[(1,2,4-triazol-1-yl)methyl]piperidine was introduced into stepwise peptide synthesis procedures using Boc chemistry and derivatives of D -4-iodophenylalanine and D -1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid. A halogen replacement analogue (I-Mex2) of a known high affinity melanocortin-4 receptor selective compound resulted. It showed a subnanomolar affinity when evaluated on the melanocortin-4 receptor in competition with the , -MSH peptide analogue 125I-NDP-MSH. By treatment with hexamethylditin and tetrakis(triphenylphosphine) palladium I-Mex2 was converted to the corresponding trimethylstannyl derivative. In the next step, Na125I was oxidized by an iodobead. Iododestannylation proceeded in the presence of 1 M phosphate buffer, pH 2.5, and the radio-active derivative 125I-Mex2 formed was separated by HPLC at 40% radiochemical yield. Preliminary investigation showed that 125I-Mex2 is useful as a radioligand for melanocortin-4 receptor binding studies. Copyright © 2003 John Wiley & Sons, Ltd. [source] Old Molecules for New Receptors: Trp(Nps) Dipeptide Derivatives as Vanilloid TRPV1 Channel BlockersCHEMMEDCHEM, Issue 4 2006Angeles Bonache Dr. Abstract The transient receptor potential vanilloid member 1 (TRPV1), an integrator of multiple pain-producing stimuli, is regarded nowadays as an important biological target for the discovery of novel analgesics. Here, we describe the first experimental evidence for the behavior of an old family of analgesic dipeptides, namely Xaa-Trp(Nps) and Trp(Nps)-Xaa (Xaa=Lys, Arg) derivatives, as potent TRPV1 channel blockers. We also report the synthesis and biological investigation of a series of new conformationally restricted Trp(Nps)-dipeptide derivatives with improved TRPV1/NMDA selectivity. Compound 15,b, which incorporates an N-terminal 2S -azetidine-derived Arg residue, was the most selective compound in this series. Collectively, a new family of TRPV1 channel blockers emerged from our results, although further modifications are required to fine-tune the potency/selectivity/toxicity balance. [source] Insect peptide hormones: a selective review of their physiology and potential application for pest controlPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 10 2003Gerd Gäde Abstract Our knowledge on primary structure, synthesis, release, receptor binding, structure,activity relationships, mode of action and degradation of, mainly, neuropeptides from insects has increased dramatically during the last 10 years or so. Here, five case studies are presented, which deal selectively with effects on: reproduction (trypsin modulating oostatic factor in mosquito); energy metabolism, locomotion and the immune system (adipokinetic hormones); water and ion balance, and feeding behaviour (diuretic hormones, kinins, sulfakinins); sex attraction (pheromone biosynthesis activating neuropeptide); and growth and development, and muscle activity (allatostatins). The literature is reviewed in the context of how the knowledge on neuropeptides has been and can be used for the design of novel, safe and selective compounds to control pest insects in the foreseeable future. Copyright © 2003 Society of Chemical Industry [source] Selective neuronal nitric oxide synthase inhibitors and the prevention of cerebral palsy,ANNALS OF NEUROLOGY, Issue 2 2009Haitao Ji PhD Objective To design a new class of selective neuronal nitric oxide synthase (NOS) inhibitors, and demonstrate that administration in a rabbit model for cerebral palsy (CP) prevents hypoxia-ischemia,induced deaths and reduces the number of newborn kits exhibiting signs of CP. Methods We used a novel computer-based drug design method called fragment hopping to identify new chemical entities, synthesized them, and conducted in vitro enzyme inhibition studies with the three isozymes of NOS and in vivo experiments to monitor cardiovascular effects on pregnant rabbit dams, NOS activity, and NOx (NO and NO2) concentration in fetal brain, and assess neurobehavioral effects on kits born to saline- and compound treated dams. Results The computer-based design led to the development of powerful and highly selective compounds for inhibition of neuronal NOS over the other isozymes. After maternal administration in a rabbit model of CP, these compounds were found to distribute to fetal brain, to be nontoxic, without cardiovascular effects, inhibit fetal brain NOS activity in vivo, reduce NO concentration in fetal brain, and dramatically ameliorate deaths and number of newborn kits exhibiting signs of CP. Interpretation This approach may lead to new preventive strategies for CP. Ann Neurol 2008 [source] Selective functional inhibition of JAK-3 is sufficient for efficacy in collagen-induced arthritis in miceARTHRITIS & RHEUMATISM, Issue 8 2010Tsung H. Lin Objective All ,-chain cytokines signal through JAK-3 and JAK-1 acting in tandem. We undertook this study to determine whether the JAK-3 selective inhibitor WYE-151650 would be sufficient to disrupt cytokine signaling and to ameliorate autoimmune disease pathology without inhibiting other pathways mediated by JAK-1, JAK-2, and Tyk-2. Methods JAK-3 kinase selective compounds were characterized by kinase assay and JAK-3,dependent (interleukin-2 [IL-2]) and ,independent (IL-6, granulocyte,macrophage colony-stimulating factor [GM-CSF]) cell-based assays measuring proliferation or STAT phosphorylation. In vivo, off-target signaling was measured by IL-22, and erythropoietin (EPO),mediated models, while on-target signaling was measured by IL-2,mediated signaling. Efficacy of JAK-3 inhibitors was determined using delayed-type hypersensitivity (DTH) and collagen-induced arthritis (CIA) models in mice. Results In vitro, WYE-151650 potently suppressed IL-2,induced STAT-5 phosphorylation and cell proliferation, while exhibiting 10,29-fold less activity against JAK-3,independent IL-6, or GM-CSF,induced STAT phosphorylation. Ex vivo, WYE-151650 suppressed IL-2,induced STAT phosphorylation, but not IL-6,induced STAT phosphorylation, as measured in whole blood. In vivo, WYE-151650 inhibited JAK-3,mediated IL-2,induced interferon-, production and decreased the natural killer cell population in mice, while not affecting IL-22,induced serum amyloid A production or EPO-induced reticulocytosis. WYE-151650 was efficacious in mouse DTH and CIA models. Conclusion In vitro, ex vivo, and in vivo assays demonstrate that WYE-151650 is efficacious in mouse CIA despite JAK-3 selectivity. These data question the need to broadly inhibit JAK-1,, JAK-2,, or Tyk-2,dependent cytokine pathways for efficacy. [source] The three-dimensional structure of MAP kinase p38,: different features of the ATP-binding site in p38, compared with p38,ACTA CRYSTALLOGRAPHICA SECTION D, Issue 8 2009Sangita B. Patel The p38 mitogen-activated protein kinases are activated in response to environmental stress and cytokines and play a significant role in transcriptional regulation and inflammatory responses. Of the four p38 isoforms known to date, two (p38, and p38,) have been identified as targets for cytokine-suppressive anti-inflammatory drugs. Recently, it was reported that specific inhibition of the p38, isoform is necessary and sufficient for anti-inflammatory efficacy in vivo, while further inhibition of p38, may not provide any additional benefit. In order to aid the development of p38,-selective compounds, the three-dimensional structure of p38, was determined. To do so, the C162S and C119S,C162S mutants of human MAP kinase p38, were cloned, expressed in Escherichia coli and purified. Initial screening hits in crystallization trials in the presence of an inhibitor led upon optimization to crystals that diffracted to 2.05,Å resolution and allowed structure determination (PDB codes 3gc8 and 3gc9 for the single and double mutant, respectively). The structure of the p38, C162S mutant in complex with the same inhibitor is also reported (PDB code 3gc7). A comparison between the structures of the two kinases showed that they are highly similar overall but that there are differences in the relative orientation of the N- and C-terminal domains that causes a reduction in the size of the ATP-binding pocket in p38,. This difference in size between the two pockets could be exploited in order to achieve selectivity. [source] Caged Protein Prenyltransferase Substrates: Tools for Understanding Protein PrenylationCHEMICAL BIOLOGY & DRUG DESIGN, Issue 3 2008Amanda J. DeGraw Originally designed to block the prenylation of oncogenic Ras, inhibitors of protein farnesyltransferase currently in preclinical and clinical trials are showing efficacy in cancers with normal Ras. Blocking protein prenylation has also shown promise in the treatment of malaria, Chagas disease and progeria syndrome. A better understanding of the mechanism, targets and in vivo consequences of protein prenylation are needed to elucidate the mode of action of current PFTase (Protein Farnesyltransferase) inhibitors and to create more potent and selective compounds. Caged enzyme substrates are useful tools for understanding enzyme mechanism and biological function. Reported here is the synthesis and characterization of caged substrates of PFTase. The caged isoprenoid diphosphates are poor substrates prior to photolysis. The caged CAAX peptide is a true catalytically caged substrate of PFTase in that it is to not a substrate, yet is able to bind to the enzyme as established by inhibition studies and X-ray crystallography. Irradiation of the caged molecules with 350 nm light readily releases their cognate substrate and their photolysis products are benign. These properties highlight the utility of those analogs towards a variety of in vitro and in vivo applications. [source] | |||||||||||||