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Old Molecules, New Concepts: [Ru(bpy)3]2+ as a Molecular Encoder,Decoder,ANGEWANDTE CHEMIE, Issue 45 2009
Paola Ceroni Prof.
Völlig logisch: Der bekannte Komplex [Ru(bpy)3]2+ (bpy=2,2,-Bipyridin) kann auf Grundlage einer Kombination elektronischer und photonischer Ein- und Ausgaben als 4-zu-2-Kodierer wie auch als 2-zu-4-Dekodierer arbeiten (siehe Bild; grau C, blau N, rot Ru). Das System lässt sich in situ ohne Zugabe chemischer Reagentien zurücksetzen und bietet einen alternativen Weg zur Herstellung molekularer Festkörperelektroniken und chemischer Computer. [source]
Old Molecules for New Receptors: Trp(Nps) Dipeptide Derivatives as Vanilloid TRPV1 Channel BlockersCHEMMEDCHEM, Issue 4 2006
Angeles 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]
Liver heparan sulfate proteoglycans: Old molecules provide new insights on lipoprotein metabolism,HEPATOLOGY, Issue 4 2007
Ph.D., Víctor Cortés M.D.
No abstract is available for this article. [source]
New tricks of an old molecule: lifespan regulation by p53AGING CELL, Issue 5 2006
Johannes H. Bauer
Summary As guardian of the genome the tumor suppressor p53 controls a crucial point in protection from cellular damage and response to stressors. Activation of p53 can have beneficial (DNA repair) or detrimental (apoptosis) consequences for individual cells. In either case activation of p53 is thought to safeguard the organism at large from the deleterious effects of various stresses. Recent data suggest that the function of p53 might also play a role in the regulation of organismal lifespan. Increased p53 activity leads to lifespan shortening in mice, while apparent reduction of p53 activity in flies leads to lifespan extension. Although the mechanism by which p53 regulates lifespan remains to be determined, these findings highlight the possibility that careful manipulation of p53 activity during adult life may result in beneficial effects on healthy lifespan. [source]
Accurate prediction of the blood,brain partitioning of a large set of solutes using ab initio calculations and genetic neural network modelingJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 11 2006
Abstract A genetic algorithm-based artificial neural network model has been developed for the accurate prediction of the blood,brain barrier partitioning (in logBB scale) of chemicals. A data set of 123 logBB (115 old molecules and 8 new molecules) of a diverse set of chemicals was chosen in this study. The optimum 3D geometry of the molecules was estimated by the ab initio calculations at the level of RHF/STO-3G, and consequently, different electronic descriptors were calculated for each molecule. Indeed, logP as a measure of hydrophobicity and different topological indices were also calculated. A three-layered artificial neural network with backpropagation of an error-learning algorithm was employed to process the nonlinear relationship between the calculated descriptors and logBB data. Genetic algorithm was used as a feature selection method to select the most relevant set of descriptors as the input of the network. Modeling of the logBB data by the only quantum descriptors produced a 5:4:1 ANN structure with RMS error of validation and crossvalidation equal to 0.224 and 0.227, respectively. Better nonlinear model (RMSV and RMSCV equals to 0.097 and 0.099, respectively) was obtained by the incorporation of the logP and the principal components of the topological indices to electronic descriptors. The ultimate performances of the models were obtained by the application of the models to predict the logBB of 23 molecules that did not have contribution in the steps of model development. The best model produced RMS error of prediction 0.140, and could predict about 98% of variances in the logBB data. © 2006 Wiley Periodicals, Inc. J Comput Chem 27: 1125,1135, 2006 [source]
Enamel matrix proteins; old molecules for new applicationsORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 3 2009
Structured Abstract Authors,,, Lyngstadaas SP, Wohlfahrt JC, Brookes SJ, Paine ML, Snead ML, Reseland JE Emdogain® (enamel matrix derivative, EMD) is well recognized in periodontology, where it is used as a local adjunct to periodontal surgery to stimulate regeneration of periodontal tissues lost to periodontal disease. The biological effect of EMD is through stimulation of local growth factor secretion and cytokine expression in the treated tissues, inducing a regenerative process that mimics odontogenesis. The major (>95%) component of EMD is Amelogenins (Amel). No other active components have so far been isolated from EMD, and several studies have shown that purified amelogenins can induce the same effect as the complete EMD. Amelogenins comprise a family of highly conserved extracellular matrix proteins derived from one gene. Amelogenin structure and function is evolutionary well conserved, suggesting a profound role in biomineralization and hard tissue formation. A special feature of amelogenins is that under physiological conditions the proteins self-assembles into nanospheres that constitute an extracellular matrix. In the body, this matrix is slowly digested by specific extracellular proteolytic enzymes (matrix metalloproteinase) in a controlled process, releasing bioactive peptides to the surrounding tissues for weeks after application. Based on clinical and experimental observations in periodontology indicating that amelogenins can have a significant positive influence on wound healing, bone formation and root resorption, several new applications for amelogenins have been suggested. New experiments now confirm that amelogenins have potential for being used also in the fields of endodontics, bone regeneration, implantology, traumatology, and wound care. [source]