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Here, we report a new pentafluoropropanamido rhodamine fluorescent probe (ACS-HNE) that allows for the selective detection of neutrophil elastase (NE). ACS-HNE displayed high sensitivity, with a low limit of detection (

The elucidation of biological processes involving reactive oxygen species (ROS) facilitates a better understanding of the underlying progression of non-communicable diseases. Fluorescent probes are a powerful tool to study various ROS and have the potential to become essential diagnostic tools. We have developed a series of coumarin fluorescent probes for the selective and sensitive detection of peroxynitrite (ONOO−), a key ROS. Coumarin based probes exhibit good photostability, large Stokes shift and high quantum yields. The three ratiometric probes all contain a boronate ester motif for the detection of ONOO− and a distinctive organelle targeting group. The study of ONOO− generation in a particular organelle will allow more precise disease profiling. Hence, targeting groups for the mitochondria, lysosome and endoplasmic reticulum were introduced into a coumarin scaffold. The three ratiometric probes displayed sensitive and selective detection of ONOO− over other ROS species. All three coumarin probes were evaluated in murine RAW264.7 macrophages for detection of basal and stimulated ONOO− formation.

Two novel drug-conjugates based on a “coumarin linker” have been designed for the synergic release of a therapeutic agent and fluorescent probe for the potential application of theranostics. The drug conjugates; CC-RNS and CI-RNS were designed to be activated by reactive oxygen species or reactive nitrogen species (ROS/RNS). The fluorescence OFF-ON response was triggered by the peroxynitrite-mediated transformation of a boronic acid pinacol ester to a phenol moiety with simultaneous release of the therapeutic agents (Confirmed by HRMS). The limit of detection for peroxynitrite using CC-RNS and CI-RNS was 0.29 and 37.2 μM, respectively. Both CC-RNS and CI-RNS demonstrated the ability to visualize peroxynitrite production thus demonstrating the effectiveness of these probes for use as tools to monitor peroxynitrite-mediated drug release in cancer cell lines.

A long wavelength TCF-based fluorescent probe (TCF-ALP) was developed for the detection of alkaline phosphatase (ALP). ALP-mediated hydrolysis of the phosphate group of TCF-ALP resulted in a significant fluorescence “turn on” (58-fold), which was accompanied by a colorimetric response from yellow to purple. TCF-ALP was cell-permeable, which allowed it to be used to image ALP in HeLa cells. Upon addition of bone morphogenic protein 2, TCF-ALP proved capable of imaging endogenously stimulated ALP in myogenic murine C2C12 cells. Overall, TCF-ALP offers promise as an effective fluorescent/colorimetric probe for evaluating phosphatase activity in clinical assays or live cell systems.

Reaction of 2-formyl-aryl-boronic acids with 1,2-amino alcohols results in dynamic covalent self assembly to quantitatively afford tetracyclic macrocyclic Schiff base boracycles containing bridging boron–oxygen–boron functionality. [ABSTRACT FROM AUTHOR]

High levels of diastereoselectivity are observed for benzylation of the lithium enolates of (S)-N,N′-bis-para-methoxybenzyl-3-iso-propyl-piperazine-2,5-dione, (S)-N(1)-para-methoxybenzyl-N(4)-methyl-3-iso-propyl-piperazine-2,5-dione and (S)-N(1)-methyl-N(4)-para-methoxybenzyl-3-iso-propyl-piperazine-2,5-dione. These data suggest that the high diastereofacial selectivity observed for alkylation of these diketopiperazine templates is mainly a consequence of the relay of stereochemical information from C(3) to C(6) via the influence of 1,2-torsional strain introduced by the N-alkyl substituents, rather than through minimisation of steric interactions alone. [ABSTRACT FROM AUTHOR]

An enantiopure amine tris(phenolate) ligand containing a single stereogenic center has been used to control the propeller-like chirality of a derived pseudo-C3-symmetric titanium isopropoxide complex with excellent levels of diastereocontrol. [ABSTRACT FROM AUTHOR]

Reversible bicarbonate and carbonate liquidliquid ion transfer processes from aqueous solution into an organic 4-(3-phenylpropyl)pyridine phase are driven electrochemically with TPPMn(iii/ii) and shown to be facilitated over a wide pH range by 2-naphthylboronic acid (bicarbonate transfer potential −0.08 V vs.SCE; binding constant KAB= 102mol−1dm3and carbonate dianion transfer potential 0.07 V vs.SCE; binding constant KAB2= 2 × 1010mol−2dm6). [ABSTRACT FROM AUTHOR]

A chiral pseudo-C3-symmetric titanium triflate that employs the point chirality of a single stereogenic centre to control the propeller chirality of its aryl rings has been used to catalyse an asymmetric sulfoxidation reaction. [ABSTRACT FROM AUTHOR]

A cleavable linker strategy has been used to optimise the enolate alkylation reactions of a recyclable l-tyrosine derived polymer-supported oxazolidin-2-one for the asymmetric synthesis of a series of chiral α-alkyl acids. [ABSTRACT FROM AUTHOR]

Reaction of the sodium anion of (S)-N-(α-methylbenzyl)allylamine with two equivalents of tert-butyl cinnamate results in a remarkable tandem aza-allyl conjugate addition–Michael addition–ring closure reaction, resulting in a chiral aminocyclohexane containing six new vicinal stereogenic centres with excellent levels of stereocontrol. [ABSTRACT FROM AUTHOR]

Abstract Herein, we report the evaluation and synthesis of a reaction based fluorescent probe DCM‐Bpin for the detection of Peroxynitrite (ONOO−). DCM‐Bpin exhibits selective fluorescence off‐on response for ONOO− over other reactive oxygen species, including H2O2. Moreover, DCM‐Bpin is biocompatible and has been used to visualize exogenous ONOO− in HeLa cells.