The Effect of Substitution Pattern on Binding Ability in Regioisomeric Ion Pair Receptors Based on an Aminobenzoic Platform.

A series of ditopic ion pair receptors equipped with 4-nitrophenylurea and 1-aza-18-crown-6-ether linked by ortho-(), meta-(), and para-() substituted benzoic acid were readily synthesized in three steps from commercially available materials. The binding properties of these regioisomeric receptors were determined using UV-vis and H NMR spectroscopy in MeCN and in the solid state by single-crystal X-ray diffraction crystallography. The solution studies revealed that, apart from carboxylates, all the anions tested formed stronger complexes in the presence of sodium cations.

Carboxylate-functionalized foldamer inhibitors of HIV-1 integrase and Topoisomerase 1: artificial analogues of DNA mimic proteins.

Inspired by DNA mimic proteins, we have introduced aromatic foldamers bearing phosphonate groups as synthetic mimics of the charge surface of B-DNA and competitive inhibitors of some therapeutically relevant DNA-binding enzymes: the human DNA Topoisomerase 1 (Top1) and the human HIV-1 integrase (HIV-1 IN). We now report on variants of these anionic foldamers bearing carboxylates instead of phosphonates. Several new monomers have been synthesized with protecting groups suitable for solid phase synthesis (SPS).

Single helically folded aromatic oligoamides that mimic the charge surface of double-stranded B-DNA.

Numerous essential biomolecular processes require the recognition of DNA surface features by proteins. Molecules mimicking these features could potentially act as decoys and interfere with pharmacologically or therapeutically relevant protein-DNA interactions. Although naturally occurring DNA-mimicking proteins have been described, synthetic tunable molecules that mimic the charge surface of double-stranded DNA are not known.

Electrochemical Examination of the Structure of Thin Hydrogel Layers Anchored to Regular and Microelectrode Surfaces.

For the examination of hydrogel structure, thin layers of thermoresponsive gels based on poly(N-isopropylacrylamide) (pNIPA) and copolymer poly(N-isopropylacrylamide-co-sodium acrylate) (p(NIPA-co-AS)) were successfully anchored to microelectrode and regular electrode surfaces using the electrochemically induced free radical polymerization. The obtained layers were stable and covered the entire surface of the electrodes. Electroactive probes 1,1'-ferrocenedimethanol (Fc(CH2OH)2) and synthesized derivatives of ferrocene modified with polyethylene glycol units (Fc-PEGn) of various length (n = 4, 9, 75, and 135) were employed for studying the volume phase transition of the thin hydrogel layers and for the determination of their structural parameters.

Mirror symmetry breaking upon spontaneous crystallization from a dynamic combinatorial library of macrocyclic imines.

Spontaneous emergence of solid state chirality and mirror symmetry breaking occurred upon crystallization from a small templated dynamic combinatorial library (DCL) of achiral macrocyclic imines, and depended strongly on the nature of library building blocks (amines, aldehydes, template cations and anions) and crystallization temperature.

Dynamic combinatorial libraries of 2,5-diformylfuran-derived macrocycles.

A series of polyazamacrocycles, containing a furan moiety, have been prepared using the all-in-solution approach of dynamic combinatorial chemistry. The methodology involves the use of a range of simple, fully soluble inorganic salts as templates and fast imine-to-amine reduction followed by high-performance liquid chromatography screening for the best reaction conditions. It offers an elegant and labor-efficient alternative to the classical methodology of imine trapping via crystallization of complexes.

Controlling and measuring the equilibration of dynamic combinatorial libraries of imines.

Imine formation is one of the most powerful methods for the construction of azamacrocycles, especially when combined with Dynamic Combinatorial Chemistry. Careful NaBH 4 reduction of the imine libraries opens the possibility of determination of their composition via HPLC analysis of the resulting amine mixture. Templates, reagent concentrations, as well as reaction conditions influence the library composition.