Pattern-based sensing of sulfated glycosaminoglycans with a dynamic mixture of iron complexes.

A dynamic mixture of iron complexes was used as a colorimetric sensor for sulfated glycosaminoglycans. The sensing ensemble was prepared by mixing [FeCl(2)(H(2)O)(4)] with dipicolylamine, the functionalized bipyridyl ligand N-(6-aminohexyl)-4'-methyl-2,2'-bipyridine-4-carboxamide, and the dye Evans Blue. Upon addition of the analytes, characteristic changes in the UV-Vis spectrum of the solutions were observed. The spectral changes allowed identifying different sulfated glucosaminoglycans (unfractionated heparin, low molecular weight heparin, dextran sulfate, chondroitin sulfate A, dermatan sulfate, heparan sulfate) with the help of a linear discriminant analysis. Furthermore, it was possible to distinguish mixtures of unfractionated heparin and heparan sulfate with good resolution.

A fluorescent probe for the quantification of heparin in clinical samples with minimal matrix interference.

A red-fluorescent perylene diimide probe allows sensitive quantification of heparin, a widely used antithrombotic drug, in plasma and serum samples with minimal interference from matrix components.

Interaction of heparin with cationic molecular probes: probe charge is a major determinant of binding stoichiometry and affinity.

Fluorescent perylenediimide probes modified with 2, 4, 6, or 8 ammonium groups were synthesized and their binding to the antithrombotic drug heparin was studied by fluorescence spectroscopy in solution. The polyanionic polysaccharide strands of heparin bind more probe molecules per sugar unit when the charge of the latter is low, and stability of the probe-heparin complex increases with increasing probe charge.

Detection and neutralisation of heparin by a fluorescent ruthenium compound.

Heparin and low-molecular-weight heparin (LMWH) are commonly monitored by determination of activated clotting times or chromogenic assays. Despite their wide use, these assays determine the biological activity and not the concentration of the anticoagulants. They may be inaccurate in some circumstances such as certain disease states. In addition, there is a significant interest in alternative tests for the point-of-care detection of heparin and LMWH. Their binding to small molecules for the detection in biological matrices is poorly explored. We describe here a new optical molecular probe for the detection of LMWH in serum samples. The polycationic ruthenium compound 1 is applicable to the quantification of heparin by monitoring 630 nm fluorescence. In addition, compound 1 is a rare example of a non-polymeric low molecular weight compound which neutralises the anticoagulant activity of heparin and LMWH in plasma samples. Limitation of the method is its low sensitivity currently being improved by structural modification of compound 1.

B(C6F5)3-catalyzed formation of B-P bonds by dehydrocoupling of phosphine-boranes.

Tris(pentafluorophenyl)borane was used as a new catalyst in the formation of P-B bonds by dehydrocoupling of phosphine-boranes.