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Activity Relationships (activity + relationships)
Kinds of Activity Relationships Selected AbstractsCytotoxic Rhodium(III) Polypyridyl Complexes Containing the Tris(pyrazolyl)methane Coligand: Synthesis, DNA Binding Properties and Structure,Activity RelationshipsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 25 2009Ruth Bieda Abstract The RhIII complexes of the type [RhCl(pp)(tpm)]2+ [pp = bpy, bpm, phen, tap, dpq, dppz] 4,9 have been prepared by stepwise treatment of RhCl3·3H2O or mer,cis -[RhCl3(DMSO-,S)2(DMSO-,O)] with the appropriate polypyridyl ligand (pp) followed by the tripodal ligand tris(pyrazolyl)methane (tpm). Intermediates of the type [RhCl3(CH3OH)(pp)] 1,3 with pp = bpy, phen, dpq were also characterized but exhibit either low (3) or no (1, 2) cytotoxicity. X-ray structural analyses of [RhCl(bpy)(tpm)][PF6]24 and [RhCl(phen)(tpm)][PF6]26 were performed, and the interaction of complexes 4,9 with DNA was investigated by CD and UV/Vis spectroscopy and by gel electrophoresis. CD and viscosity studies confirm strong intercalation of dppz complex 9 into DNA. Complexes 8 and particularly 9 (IC50 = 0.43, 0.37 ,M) are potent cytotoxic agents towards the human cancer cell lines MCF-7 and HT-29, whereas respectively little (complex 6) or no activity (complexes 4, 5, 7) is observed for the other members of the series. Our findings indicate that the cytotoxicity is dependent on the hydrophobicity of both the polypyridyl and the facial coligand in these and other half-sandwich RhIII complexes. Irradiation of bpy compound 4 in the presence of plasmid pBR322 for 30 min at 311 nm at a molar ratio of r = 0.1 leads to total conversion of the supercoiled form into the nicked version. Although dppz complex 9 also functions as a photonuclease under these conditions, the degree of cleavage is much lower. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] QSAR of Human Steroid 5,-Reductase Inhibitors: Where are the differences between isoenzyme type 1 and 2?MOLECULAR INFORMATICS, Issue 6 2004Michael Abstract Quantitative Structure Activity Relationships have been established for inhibitors of human steroid 5,-reductase including 6-azasteroids and non-steroidal compounds. From the applied descriptors, those related to the molecular geometry, electronic properties, and the electrostatic surface were derived from semi-empirical AM1 calculations. A chemical reaction as part of the inhibitory action is indicated by the presence of the ionization potential in the descriptor space. Strong similarities between the variables for the prediction of the binding affinity to the type 1 and IC50 values for the type 2 isoform of the 5,-reductase were observed. The most pronounced differences in the linear regression QSAR equations were found for the descriptors accounting for the hydrogen-bonding interaction, suggesting a different hydrogen-bonding pattern in the binding pocket of both isoforms. Furthermore, the topological indices together with the surface related descriptors point towards a lower content of aromatic amino acids in the binding site of the type 2 isoenzyme. Consequences for the design of new inhibitors are discussed. [source] Ortho Effects in Quantitative Structure Activity Relationships for Lipase Inhibition by Aryl CarbamatesMOLECULAR INFORMATICS, Issue 8 2003Gialih Lin Abstract Ortho -substituted phenyl- N -butyl carbamates (1,11) are synthesized and evaluated for their inhibition effects on Pseudomonas species lipase. Carbamates 1,11 are characterized as pseudo-substrate inhibitors of the enzyme. The logarithms of dissociation constant (Ki), carbamylation constant (k2), and bimolecular inhibition constant (ki) multiply linearly correlate with Hammett substituent constant (,), Taft-Kutter-Hansch ortho steric constant (ES), and Swan-Lupton field constant (F). For ,logKi -, logk2 -, and logki -correlations, values of ,, ,, f, ,XR are 0.2, ,0.06, ,1.7, 0.8; 0.0, 0.0, 1.0, ,0.07; and ,1.8, 7, 0.6, 5; respectively. The enzyme inhibition mechanism is composed of four steps: 1) the first step which is protonation of carbamates 1,11, 2) the second step (Ki1) which involves in the proton 1,3-shift of protonated carbamates 1,11 then the pseudo- trans to cis conformational change, 3) the third step (Ki2) which is formation of a negative charged enzyme-inhibitor tetrahedral intermediate, and 4) the fourth step (k2) which is the carbamylation step. The former three steps are likely composed of the Ki step. There is little ortho steric enhancement effect in the Ki step. From cross-interaction correlations, distance between carbamate and phenyl substituents in transition state for the Ki step is relatively short due to a large ,XR value of 7. The k2 step is insensitive to ortho steric effect. The k2 step involves in departure of leaving group, substituted phenol in which is protonated from the proton 1,3-shift but not from the active site histidine of the enzyme. From cross-interaction correlations, the distance between carbamate and phenyl substituents in transition state for the k2 step is relatively long due to a small ,XR value of 0.6. [source] Improving Opportunities for Regulatory Acceptance of QSARs: The Importance of Model Domain, Uncertainty, Validity and PredictabilityMOLECULAR INFORMATICS, Issue 3 2003Abstract For Quantitative Structure Activity Relationships (QSARs) to be accepted by the regulated and regulatory communities, their scope for use needs to be agreed upon by government and industry. This paper discusses the importance of model domain, uncertainty, validity and predictability assessment in promoting the regulatory acceptance of QSARs. [source] Structure,Activity Relationships through Sequencing (StARTS) Defines Optimal and Suboptimal RNA Motif Targets for Small Molecules,ANGEWANDTE CHEMIE, Issue 22 2010Pradeep Velagapudi Genau ins Schwarze: Ein kombinierter Computer- und experimenteller Ansatz identifiziert optimale (und suboptimale) RNA-Motive als Angriffsziele niedermolekularer Verbindungen mithilfe eines zweidimensionalen kombinatorischen Screenings. Die als ,Struktur-Aktivitäts-Beziehungen durch Sequenzierung" (StARTS) bezeichnete Methode nutzt Sequenzinformationen der gewählten RNA-Motive für die Bindung eines Liganden. [source] Insights into Sequence,Activity Relationships amongst Baeyer,Villiger Monooxygenases as Revealed by the Intragenomic Complement of Enzymes from Rhodococcus jostii RHA1CHEMBIOCHEM, Issue 7 2009Claudia Szolkowy Abstract TheRhodococcus jostiiRHA1 genome encodes a number of enzymes that can be exploited as biocatalysts. Study of the substrate spectrum and enantioselectivity of Baeyer,Villiger monooxygenases from R. jostii allowed the identification of short amino acid sequences specific to groups displaying certain catalytic characteristics. The gel illustrates the substrate acceptance spectra and selectivities of the different proteins. Microbial genome sequences are providing a wealth of information on new enzymes that have considerable potential as biocatalysts. The recently sequenced genome of Rhodococcus jostii RHA1, for example, has revealed an impressive array of catabolic enzymes, including many putative Baeyer,Villiger monooxygenases (BVMOs). We have cloned 23 target BVMO sequences from the genome of R. jostii RHA1 and heterologously expressed 13 of these as soluble proteins to unearth new substrate specificities and selectivities. Whole-cell biocatalysts expressing the genes were screened against seven different test substrates. Each of these catalysts displayed activity toward at least three ketones. We observed a remarkable diversity of both regio- and enantioselectivity among the BVMOs from R. jostii RHA1 for the transformation of two chiral substrates, with some enzymes displaying high enantioselectivity for the isomers of 2-methylcyclopentanone. With the notable exception of the product of gene ro03437, named MO14, the biocatalysts' sequences correlated well with their respective activities and selectivities. This correlation allowed the identification of sequence motifs specific to subgroups of the BVMOs from R. jostii and other organisms. Overall, the data improve predictive models of BVMO activity from sequence and suggest new avenues to pursue in engineering these enzymes. [source] An Approach towards the Quantitative Structure,Activity Relationships of Caffeic Acid and its DerivativesCHEMBIOCHEM, Issue 9 2004Rajeshwar P. Verma Dr. Abstract Caffeic acid and its derivatives are already known to possess a wide range of biological activities. We have developed quantitative structure,activity relationships (QSARs) for different series of caffeic acid derivatives (including caffeic acid) in order to understand the chemical,biological interactions governing antitumor activity against six different tumor cell lines, nitric oxide production, anti-HIV and enzymatic activities, and binding affinity to the lck domain. QSAR results have shown that the different activities of caffeic acid and its derivatives are largely dependent on their hydrophobicity or molar refractivity, with a bilinear correlation being the most important. [source] ChemInform Abstract: Structure,Activity Relationships and Mechanism of Action of Antitumor Bis 8-Hydroxyquinoline Substituted Benzylamines.CHEMINFORM, Issue 23 2010Jean-Louis Kraus Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Nitrogen Ligands in Copper-Catalyzed Arylation of Phenols: Structure,Activity Relationships and Applications.CHEMINFORM, Issue 51 2007Armelle Ouali Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Synthesis and Structure,Activity Relationships of 3H-Quinazolin-4-ones and 3H-Pyrido[2,3-d]pyrimidin-4-ones as CXCR3 Receptor Antagonists.CHEMINFORM, Issue 41 2007Stefania Storelli Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Synthesis and Structure,Activity Relationships of 3,4-Diaminocyclobut-3-ene-1,2-dione CXCR2 Antagonists.CHEMINFORM, Issue 47 2006J. Robert Merritt Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Synthesis and Structure,Activity Relationships of 8-Azabicyclo[3.2.1]octane Benzylamine NK1 Antagonists.CHEMINFORM, Issue 17 2006Christopher G. Thomson Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Design, Synthesis, and Structure,Activity Relationships of 3,4-Dihydropyridopyrimidin-2(1H)-one Derivatives as a Novel Class of Sodium/Calcium Exchanger Inhibitor.CHEMINFORM, Issue 12 2006Hirohiko Hasegawa Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Synthesis, Structure,Activity Relationships, and Anxiolytic Activity of 7-Aryl-6,7-dihydroimidazoimidazole Corticotropin-Releasing Factor 1 Receptor Antagonists.CHEMINFORM, Issue 50 2005Xiaojun Han Abstract For Abstract see ChemInform Abstract in Full Text. [source] Structure,Activity Relationships for 2-Anilino-6-phenylpyrido[2,3-d]pyrimidin-7(8H)-ones as Inhibitors of the Cellular Checkpoint Kinase Wee1.CHEMINFORM, Issue 31 2005Brian D. Palmer Abstract For Abstract see ChemInform Abstract in Full Text. [source] Synthesis and Structure,Activity Relationships of Isoxazole Carboxamides as Growth Hormone Secretagogue Receptor Antagonists.CHEMINFORM, Issue 26 2005Zhili Xin Abstract For Abstract see ChemInform Abstract in Full Text. [source] In vitro Antifungal Properties, Structure,Activity Relationships and Studies on the Mode of Action of N-Phenyl, N-Aryl, N-Phenylalkyl Maleimides and Related Compounds.CHEMINFORM, Issue 26 2005Susana A. Zacchino Abstract For Abstract see ChemInform Abstract in Full Text. [source] Synthesis and Structure,Activity Relationships of Novel IKK-, Inhibitors.CHEMINFORM, Issue 48 2004Part 3. No abstract is available for this article. [source] Structure,Activity Relationships of Untenone A and Its Derivatives for Inhibition of DNA Polymerases.CHEMINFORM, Issue 31 2004Fumiyo Saito Abstract For Abstract see ChemInform Abstract in Full Text. [source] Synthesis and Structure,Activity Relationships of a New Set of 1,2,4-Triazolo[4,3-a]quinoxalin-1-one Derivatives (I) and (II) as Adenosine Receptor Antagonists.CHEMINFORM, Issue 46 2003Vittoria Colotta No abstract is available for this article. [source] A New Class of Histamine H3 -Receptor Antagonists: Synthesis and Structure,Activity Relationships of 7,8,9,10-Tetrahydro-6H-cyclohepta[b]quinolinesCHEMINFORM, Issue 42 2003Sean C. Turner Abstract For Abstract see ChemInform Abstract in Full Text. [source] Structure,Activity Relationships of First Bishydroxymethyl-Substituted Cage Dimeric 4-Aryl-1,4-dihydropyridines as HIV-1 Protease Inhibitors.CHEMINFORM, Issue 38 2003Andreas Hilgeroth Abstract For Abstract see ChemInform Abstract in Full Text. [source] Design, Synthesis, and Structure,Activity Relationships of Unsubstituted Piperazinone-Based Transition State Factor Xa Inhibitors.CHEMINFORM, Issue 25 2003Wenrong Huang Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: Synthesis and Structure,Activity Relationships of a Novel Series of HIV-1 Protease Inhibitors Encompassing ABT-378 (Lopinavir).CHEMINFORM, Issue 33 2002Hing L. Sham Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Structure,Activity Relationships of New Inhibitors of Mammalian 2,3-Oxidosqualene Cyclase Designed from Isoquinoline DerivativesCHEMINFORM, Issue 32 2002Jean Binet Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Structure,Activity Relationships Among Novel Phenoxybenzamine-Related ,-Chloroethylamines.CHEMINFORM, Issue 28 2002Dario Giardina Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: A Novel Synthesis of 2-Arylpyrrolo[1,2-a]pyrimid-7-ones and Their Structure,Activity Relationships as Potent GnRH Receptor Antagonists.CHEMINFORM, Issue 24 2002Yun-Fei Zhu Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Investigation of 5-Nitrofuran Derivatives: Synthesis, Antibacterial Activity, and Quantitative Structure,Activity Relationships.CHEMINFORM, Issue 9 2002Jose Ricardo Pires Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Aziridinyl Quinone Antitumor Agents Based on Indoles and Cyclopent[b]indoles: Structure,Activity Relationships for Cytotoxicity and Antitumor Activity.CHEMINFORM, Issue 8 2002Edward B. Skibo Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Design, Synthesis, and Structure,Activity Relationships of a Series of 3-[2-(1-Benzylpiperidin-4-yl)ethylamino]pyridazine Derivatives as Acetylcholinesterase Inhibitors.CHEMINFORM, Issue 49 2001Jean-Marie Contreras Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] | |||||||||||||||||||||||||||||||||||||||||||