Publications by authors named "Orit Redy-Keisar"

A systematic study of trends in the lipophilicity of prominent representatives of the opioid family, including natural, semisynthetic, synthetic, and endogenous neuropeptide opioids, is described. This was enabled by a straightforward H NMR-based log/ determination method developed for compounds holding at least one aromatic hydrogen atom. Moreover, the new method enables a direct simultaneous log determination of opioid mixtures, overcoming the high sensitivity of this family to the measurement conditions, which is critical when a determination of the exact Δlog values of matched pairs is required.

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Highly sensitive chemiluminescence-based probes that effectively detect and differentiate between the extremely toxic real G- and V-type organophosphorus chemical warfare agents (OPCWAs) are presented. This straightforward approach does not require any instrumentation or light source; hence, it appears ideal for the future development of field colorimetric detectors.

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Fluorine atoms play an important role in all branches of chemistry and accordingly, it is very important to study their unique and varied effects systematically, in particular, the structure-physicochemical properties relationship. The present study describes exceptional physicochemical effects resulting from a H/F exchange at the methylene bridge of gem-difunctional compounds. The Δlog P values, that is, the change in lipophilicity, observed for the CH /CF replacement in various α,α-phenoxy- and thiophenoxy-esters/amides, diketones, benzodioxoles and more, fall in the range of 0.

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Systematically studying the lipophilicity of phosphorus compounds is of great importance for many chemical and biological fields and particularly for medicinal chemistry. Here, we report on the study of trends in the lipophilicity of a wide set of phosphorus compounds relevant to drug design including phosphates, thiophosphates, phosphonates, thiophosphonates, bis-phosphonates, and phosphine chalcogenides. This was enabled by the development of a straightforward log determination method for phosphorus compounds based on P-NMR spectroscopy.

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Active gels present unique potential for the decontamination of chemical warfare agents (CWAs) as they strongly adhere to surfaces, thus allowing prolonged decontamination time. Herein, we present a decontamination hydrogel based on polyvinyl alcohol/borax, which contains sodium perborate (NaBO), as an in situ source of the active ingredient hydrogen peroxide. Developed as a binary formulation, this gel instantly forms and effectively sticks when sprayed on various matrices, including porous and vertically positioned matrices.

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A novel SWIFT-based strategy for fluorimetric detection of practical amounts (minimal effective dose or lower) of chemical warfare agents is reported. This strategy employs readily available reagents and allows distinguishing between the V and G agents, as well as their discrimination from potential interferents.

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The detection of chemical or biological analytes in response to molecular changes relies increasingly on fluorescence methods. Therefore, there is a substantial need for the development of improved fluorogenic dyes. In this study, we demonstrated how an intramolecular hydrogen bond activates a dormant acceptor through a charge induction between phenolic hydrogen and a heteroaryl nitrogen moiety.

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The ability to monitor drug release in vivo provides essential pharmacological information. We developed a new modular approach for the preparation of theranostic prodrugs with a turn-ON near-infrared (NIR) fluorescence mode of action. The prodrugs release their chemotherapeutic cargo and an active cyanine fluorophore upon reaction with a specific analyte.

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Near-infrared (NIR) fluorescent dyes are gaining increased attention due to their potential to serve as molecular probes for in vivo imaging. Here, we demonstrate that oligoglycerol dendrons effectively enhance the fluorescence properties of an NIR dye by increasing the solubility in water and the prevention of aggregate formation. First- and second-generation oligoglycerol dendrons were conjugated to an NIR dye via a dipolar-cycloaddition (click) reaction.

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5-Hydroxymethylcytosine (5hmC), a modified form of the DNA base cytosine, is an important epigenetic mark linked to regulation of gene expression in development, and tumorigenesis. We have developed a spectroscopic method for a global quantification of 5hmC in genomic DNA. The assay is performed within a multiwell plate, which allows simultaneous recording of up to 350 samples.

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This protocol describes the synthesis of modular turn-ON QCy7-based probes for the detection of biologically relevant analytes, such as hydrogen peroxide, ubiquitous sulfhydryl and β-galactosidase. The probes presented herein are prepared through a simple procedure that involves the preliminary alkylation of 4-hydroxy-isophthalaldehyde with a relevant analyte-responsive protecting group, followed by condensation of the resulting product with 2 equivalents of sulfo-indolium moieties. Evaluation of the turn-ON near-IR fluorescence response to their relevant analytes for the three different QCy7 probes is also reported.

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