Search results for "combinatorial"

DNA damage profiles induced by oxidizing agents

1995

DNA damage photo-induced by chloroharmine isomers: hydrolysis versus oxidation of nucleobases

2018

Photodynamic therapy (PDT) is an emerging clinical treatment currently being used against a wide range of both cancerous and noncancerous diseases. The search for new active photosensitizers as well as the development of novel selective delivery systems are the major challenges faced in the application of PDT. We investigated herein three chloroharmine derivatives (6-, 8- and 6,8-dichloroharmines) with quite promising intrinsic photochemical tunable properties and their ability to photoinduce DNA damage in order to elucidate the underlying photochemical mechanisms. Data revealed that the three compounds are quite efficient photosensitizers. The overall extent of photo-oxidative DNA damage i…

Increasing the Coverage of Medicinal Chemistry-Relevant Space in Commercial Fragments Screening

2014

Analyzing the chemical space coverage in commercial fragment screening collections revealed the overlap between bioactive medicinal chemistry substructures and rule-of-three compliant fragments is only ∼25%. We recommend including these fragments in fragment screening libraries to maximize confidence in discovering hit matter within known bioactive chemical space, while incorporation of nonoverlapping substructures could offer novel hits in screening libraries. Using principal component analysis, polar and three-dimensional substructures display a higher-than-average enrichment of bioactive compounds, indicating increasing representation of these substructures may be beneficial in fragment …

Some recent contributions to routing and location problems

2003

CORAL 2003, a Conference on Routing and Location, washeld in Puerto de la Cruz (Tenerife, Spain) from February24–26, 2003. A wonderful place, close to the black sand ofthe beach, and a nice temperature welcomed a group ofsenior and young researchers from Canada, England,France, Germany, and Spain. Social activities were alsoprovided and sponsored by the Cabildo Insular de Tenerife(the local government) and TITSA (the public bus transpor-tation company on the island). The conference corre-sponded to the third annual meeting of a research project,funded by the Spanish Ministry of Science and Technology,developing a Decision Support System for Vehicle Routingand Facility Location Problems (SAD…

Adsorption and Detection of DNA Dendrimers at Carbon Electrodes

1998

Made available in DSpace on 2022-04-28T19:53:27Z (GMT). No. of bitstreams: 0 Previous issue date: 1998-01-01 Dendritic nucleic acids are highly branched and ordered molecular structures, possessing numerous single-stranded oligonucleotide arms, which hold great promise for enhancing the sensitivity of DNA biosensors. This article evaluates the interfacial behavior and redox activity of nucleic acid dendrimers at carbon paste electrodes, in comparison to DNA. Factors influencing the adsorption behavior, including the adsorption potential and time, solution conditions, or dendrimer concentration, are explored. The strong adsorption at the anodically pretreated carbon surface is exploited for …

Tuning the pH-Switch of Supramolecular Polymer Carriers for siRNA to Physiologically Relevant pH

2017

The preparation of histidine enriched dendritic peptide amphiphiles and their self-assembly into multicomponent pH-switchable supramolecular polymers is reported. Alternating histidine and phenylalanine peptide synthons allow the assembly/disassembly to be adjusted in a physiologically relevant range of pH 5.3-6.0. Coassembly of monomers equipped with dendritic tetraethylene glycol chains with monomers bearing peripheral primary amine groups leads to nanorods with a tunable cationic surface charge density. These surface functional supramolecular polycations are able to reversibly bind short interfering RNA (siRNA). The nanorod-like supramolecular polymers, their complexation with siRNA, and…

ChemInform Abstract: New Concepts in Multidentate Ligand Chemistry: Effects of Multidentarity on Catalytic and Spectroscopic Properties of Ferrocenyl…

2008

This tutorial review devoted to ligand chemistry deals with the design and properties of ferrocenyl polyphosphines, an original class of multidentate ligands. The development of a varied library of ferrocenyl tetra-, tri- and diphosphine ligands is reviewed. The multidentate nature of these species has led to unique spectroscopic and catalytic properties, in which the spatial proximity of phosphorus atoms is crucial. Regarding their catalytic applications, the key issues of catalyst longevity and ultralow catalyst loadings are discussed. Another part is concerned with fundamental advances gained in physical chemistry for structure elucidation by the study of the intriguing “through-space” N…

Copper(I) Iodide Polyphosphine Adducts at Low Loading for Sonogashira Alkynylation of Demanding Halide Substrates: Ligand Exchange Study between Copp…

2010

The prestabilization of copper iodide with a multidentate ferrocenyl phosphine ligand promotes the palladium-catalyzed cross-coupling of demanding halides with phenylacetylene in a selective way. Novel CuI-triphosphine adducts are described in the solid state and in solution. Their use allowed the introduction of the copper iodide cocatalyst in unprecedented low amounts (0.4 to 0.1 mol %) in systems also employing low amounts of “ligand-free” [PdII(η3-allyl)Cl]2 precursor (0.2 to 0.05 mol %). The scope of substrates is reported, and electronically or sterically deactivated bromides were efficiently coupled. Concerning aryl chlorides, electron-poor activated substrates were also coupled usin…

Dehydrogenative Anodic C−C Coupling of Phenols Bearing Electron‐Withdrawing Groups

2019

Abstract We herein present a metal‐free, electrosynthetic method that enables the direct dehydrogenative coupling reactions of phenols carrying electron‐withdrawing groups for the first time. The reactions are easy to conduct and scalable, as they are carried out in undivided cells and obviate the necessity for additional supporting electrolyte. As such, this conversion is efficient, practical, and thereby environmentally friendly, as production of waste is minimized. The method features a broad substrate scope, and a variety of functional groups are tolerated, providing easy access to precursors for novel polydentate ligands and even heterocycles such as dibenzofurans.

General route to dissymmetric heteroannular-functionalized ferrocenyl 1,2-diphosphines: selective synthesis and characterization of a new class of tr…

2006

Several monosubstituted-cyclopentadienyl anions (A-Li) and [1,2-bis(diphenylphosphino)-4-tert-butylcyclopentadienyl]lithium (B-Li) react with FeCl2 to afford a novel class of multidentate ferroceny...