Warfarin: an environment‐dependent switchable molecular probe

Abstract

The complex nature of the structure of the anticoagulant warfarin is reflected in the diversity of binding modes observed in warfarin-protein recognition systems. A series of theoretical, 1 H-NMR and steady state and time resolved fluorescence spectroscopic studies, have been used to establish correlations between the molecular environment provided by various solvent systems and the relative concentrations of the various members of warfarin's ensemble of isomers. A consequence of these observations is that the judicious choice of solvent system or molecular environment of warfarin allows for manipulation of the position of the equilibrium between isomeric structures such as the hemiacetal and open phenol-keto forms, the latter even possible in a deprotonated form, where in each case unique spectroscopic properties are exhibited by the respective structures. Collectively, warfarin's capacity to adapt its structure as a function of environment in conjunction with the fluorescence behaviours of the various isomers together provide an environment-dependent molecular switch with reporter properties, which allows for the simultaneous detection of warfarin in different states with lifetimes spanning the range < 0.10-5.5 ns. These characteristics are here used to examine warfarin binding domains in a series of materials (solvents, protein, inorganic matrix and synthetic polymer). Moreover, these studies demonstrate the potential for using warfarin, or other switchable analogues thereof, as a tool for studying molecular level characteristics, for example local dielectricity.

Cosolubilization of Coumarin30 and Warfarin in Cationic, Anionic, and Nonionic Micelles: A Micelle–Water Interfacial Charge Dependent FRET

“…The higher value of τ 1 and appearance of τ 2 is the manifestation of higher viscosity and complex forming tendency of the solvent with WF as observed in ethanol and propanol solvents. 60 This is in correlation with the significant increase in the quantum yield in this solvent. The data can be used to justify the results obtained in the presence of different types of micelles as discussed below.…”

Molecular imprinting science and technology: a survey of the literature for the years 2004-2011

“…Traditionally, spectroscopic methods have been invaluable for the study of fundamental aspects of the molecular imprinting process, in particular, events taking place in prepolymerization mixtures. The work of recent years has seen a continued use of NMR, IR and UV‐Vis spectroscopies for characterizing monomer‐template interactions, to the point where such studies are becoming essential aspects of MIP design, either for the screening of monomers for interaction with template or for the validation of computational design data. A recent trend is the significant increase in the number of spectroscopic studies of ligand‐MIP interactions.…”

Release of Warfarin from Human Serum Albumin by Water‐soluble CdSe Nanotetrapods

“…[32] A lifetime of 2.4 ns is obtained for warfarin bound to HSA, which is in agreement with an earlier report. [36,37] The amplitude of this component increases progressively from 0 to 0.68 with increase in HSA concentration from 0 to 40 μM ( Table 1, Table ST4), indicating an increase in the degree of binding of warfarin by HSA. Upon addition of nanotetrapods to a solution of warfarin in 40 μM HSA, the decays become progressively faster, confirming the disruption of HSA-warfarin complex ( Figures S7(b), 4(b)).…”

“…[32][33][34] Warfarin is used as a biomarker for probing the binding of additional biomolecules in site. [35][36][37] Water solubility of nanocrystals is a key requirement in their biological applications and catalysis in aqueous medium. [38][39][40] They find application in sensing analytes in aqueous medium.…”