James H R Tucker

• BSc, PhD
• Professor at University of Birmingham

The reversible photocontrol of an enzyme governing blood coagulation is demonstrated. The thrombin binding aptamer (TBA), was rendered photochromic by modification with two anthracene groups. Light-triggered anthracene photodimerisation distorts its structure, inhibiting binding of the enzyme thrombin, which in turn triggers catalysis and the resul...

Aptamers are short single strand nucleic acid sequences that exhibit high-affinity molecular recognition towards non nucleic acid targets. They offer many benefits over antibodies, but still suffer from variable affinities...

We report on dual, light‐responsive and redox‐active foldamers that demonstrate reversible and robust stimuli‐induced behaviour. Herein, UV/Vis, ¹H NMR and circular dichroism (CD) spectroscopy and cyclic voltammetry have been used to establish the reversibility and highly robust nature of the light‐ and redox‐driven behaviour of these new foldamers...

The phosphoantigen (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP) is an established activator of Vγ9/Vδ2 T cells and stimulates downstream effector functions including cytotoxicity and cytokine production. In order to improve its drug-like properties, we herein report the design, synthesis, serum stability, in vitro metabolism, and biologi...

Chemical modification of aptamers is an important step to improve their performance and stability in biological media. This can be performed either during their identification (mod‐SELEX) or after the in vitro selection process (post‐SELEX). In order to reduce the complexity and workload of the post‐SELEX modification of aptamers, we have evaluated...

A new class of cobalt catalytic system for asymmetric hydrogenation of ketones was herein reported, involving the development of novel ferrocene-based secondary phosphine oxide ligands. An unusual P-O bidentate coordination pattern with cobalt was confirmed by an X-ray diffraction study. The bichelating tetrahedral cobalt(II) complexes afforded hig...

A plug-and-play sandwich assay platform for the aptamer-based detection of molecular targets using linear dichroism (LD) spectroscopy as a read-out method has been demonstrated. A 21-mer DNA strand comprising the plug-and-play linker was bioconjugated onto the backbone of the filamentous bacteriophage M13, which gives a strong LD signal due to its...

Virus recognition has been driven to the forefront of molecular recognition research due to the COVID‐19 pandemic. Development of highly sensitive recognition elements, both natural and synthetic is critical to facing such a global issue. However, as viruses mutate, it is possible for their recognition to wane through changes in the target substrat...

Methods for the real-time monitoring of the substrate acceptance of modified nucleotides by DNA polymerases are in high demand. In a step towards this aim, we have incorporated ferrocene-based abasic nucleotides into DNA templates and evaluated their compatibility with enzymatic synthesis of unmodified and modified DNA. All canonical nucleotides ca...

Methods for the real-time monitoring of the substrate acceptance of modified nucleotides by DNA polymerases are in high demand. In a step towards this aim, we have incorporated ferrocene-based abasic nucleotides into DNA templates and evaluated their compatibility with enzymatic synthesis of unmodified and modified DNA. All canonical nucleotides ca...

Methods for the real-time monitoring of the substrate acceptance of modified nucleotides by DNA polymerases are in high demand. In a step towards this aim, we have incorporated ferrocene-based abasic nucleotides into DNA templates and evaluated their compatibility with enzymatic synthesis of unmodified and modified DNA. All canonical nucleotides ca...

Pancreatic ductal adenocarcinoma (PDAC) is a disease that remains refractory to existing treatments including the nucleoside analogue gemcitabine. In the current study we demonstrate that an organometallic nucleoside analogue, the ferronucleoside 1-(S, Rp), is cytotoxic in a panel of PDAC cell lines including gemcitabine resistant MIAPaCa2, with IC...

Deoxyribonucleic acid (DNA) has been hypothesized to act as a molecular wire due to the presence of an extended π-stack between base pairs, but the factors that are detrimental in the mechanism of charge transport (CT) across tunnel junctions with DNA are still unclear. Here we systematically investigate CT across dense DNA monolayers in large-area...

Controllable higher-order assembly is a central aim of macromolecular chemistry. An essential challenge to developing these molecules is improving our understanding of the structures they adopt under different conditions. Here, we demonstrate how flow linear dichroism (LD) spectroscopy is used to provide insights into the solution structure of a ch...

Significance We report a rapid COVID-19 assay that gives a sample-to-signal time of under 10 min. The current gold-standard COVID-19 assay uses PCR, where strands of DNA are copied (amplified) many times to generate a read-out signal. However, as the virus genome is RNA, first conversion into DNA is required using reverse transcription (RT) before...

Pancreatic ductal adenocarcinoma (PDAC) is a disease that remains largely refractory to existing treatments including the nucleoside analogue gemcitabine. In the current study we demonstrate that the ferronucleoside 1-(S,Rp) is cytotoxic in a panel of PDAC cell lines including gemcitabine resistant MIAPaCa2, with IC50 values comparable to cisplatin...

The dynamic nature of micellar nanostructures is employed to form a self-assembled Förster resonance energy transfer (FRET) nanoplatform for enhanced sensing of DNA. The platform consists of lipid oligonucleotide FRET probes incorporated into micellar scaffolds, where single recognition events result in fusion and fission of DNA mixed micelles, tri...

We report a rapid isothermal method for detecting SARS-CoV-2, the virus responsible for COVID-19. The procedure uses a novel reverse transcriptase-free (RTF) approach for converting RNA into DNA, which triggers a rapid amplification using the Exponential Amplification Reaction (EXPAR). Deploying the RNA-to-DNA conversion and amplification stages of...

Modified thymine bases, each containing a polymerizable group (either carboxymethylvinyl or acrylamide) at the 5-position, have been incorporated multiple times into an aptamer sequence allowing the sequence to act as...

A family of ferrocene-based chiral PNP ligands is reported. These tridentate ligands were successfully applied in Mn-catalyzed asymmetric hydrogenation of ketones, giving high enantioselectivities (92%∼99% ee for aryl alkyl ketones) as well as high efficiencies (TON up to 2000). In addition, dialkyl ketones could also be hydrogenated smoothly. Mang...

Nucleic acid detection is an important part of our bio-detection arsenal, with the COVID-19 pandemic clearly demonstrating the importance to healthcare of rapid and efficient detection of specific pathogenic sequences. As part of the drive to establish new DNA detection methodologies and signal read-outs, here we show how linear dichroism (LD) spec...

The synthesis and characterisation of novel metal-modified DNA precursors for fuel cell catalyst development are described. Material precursors in the form of metal-DNA complexes were prepared through the reaction of DNA with cisplatin at various loadings and spectroscopically tested to confirm the platinum binding mode and the degree of complexati...

Iron works: A ferrocene derivative, one of a series of ferronucleosides designed by the Tucker group, shows micromolar toxicity in a range of cancer cell lines. Their latest research shows the importance to activity of having arms in adjacent positions, with the 1,1’‐regioisomer much less active in bone cancer cell lines. On the other hand, N‐ or O...

Four new bis‐substituted ferrocene derivatives containing either a hydroxyalkyl or methoxyalkyl group and either a thyminyl or methylthyminyl group have been synthesised and characterised by a range of spectroscopic and analytical techniques. They were included in a structure‐activity‐relationship (SAR) study probing anticancer activities in osteos...

Correction for ‘The challenges of glycan recognition with natural and artificial receptors’ by Stefano Tommasone et al. , Chem. Soc. Rev. , 2019, 48 , 5488–5505.

A new chiral organometallic nucleoside analogue containing ruthenocene is reported, in which alkylthymine and alkylhydroxyl groups are attached in adjacent positions on one cyclopentadienyl ring. The synthetic procedures for this metallocene derivative and two control compounds are described, along with their characterisation that include cyclic vo...

Oligodeoxynucleotides incorporating internucleotide phosphoroselenolate linkages have been prepared under solid-phase synthesis conditions using dimer phosphoramidites. These dimers were constructed following the high yielding Michealis-Arbuzov (M-A) reaction of nucleoside H-phosphonate derivatives with 5ʹ-deoxythymidine-5ʹ-selenocyanate and subseq...

The synthesis of a novel modified nucleoside phosphoramidite, Acrylamide-dT-CE phosphoramidite, obtained in three steps from commercially available starting materials, is reported. It was readily incorporated into thrombin binding aptamer (TBA) sequences using automated solid-phase synthesis under ultra-mild conditions, with the modification shown...

Glycans – simple or complex carbohydrates – play key roles as recognition determinants and modulators of numerous physiological and pathological processes. Thus, many biotechnological, diagnostic and therapeutic opportunities abound for molecular recognition entities that can bind glycans with high selectivity and affinity. This review begins with...

Microorganisms such as bacterial cells only possess small quantities of DNA, therefore in order to diagnose infection nucleic acid amplification tests are exploited. These tests allows for the large-scale amplification of DNA from quantities as low as 0.02 μg μL-1. However, the most common method, PCR possesses a series of disadvantages severely li...

Gliomas are highly malignant brain tumours characterised by extensive areas of poor perfusion which subsequently leads to hypoxia and reduced survival. Therapies that address the hypoxic microenvironment are likely to significantly improve patient outcomes. Verteporfin, a benzoporphyrin-like drug, has been suggested to target the Yes-associated pro...

A redox-active ferrocene-based heteroditopic receptor bearing a boronic acid (as a catechol recognition site) and a benzo-18-crown-6-ether unit (as an ammonium ion recognition site) was synthesized. A 1:1 ditopic complex with dopamine was evidenced by mass spectrometry and NMR spectroscopy. Cyclic voltammetry measurements on the receptor in the pre...

The labelling of DNA oligonucleotides with signalling groups that give a unique response to duplex formation depending on the target sequence is a highly effective strategy in the design of DNA-based hybridisation sensors. A key challenge in the design of these so-called base discriminating probes (BDPs) is to understand how the local environment o...

Synthetic hydrogen-bonding receptors are described, which incorporate a central electroactive ferrocene moiety grafted with two adjacent bis(amido)pyridine motifs and an aliphatic tether (14 and 18 methylene units for 1 and 2, respectively) completing the macrocycle. The crystallographic structure, barbiturate guest-binding studies and electrochemi...

Since loss of function mutations of PINK1 lead to early-onset Parkinson's disease, there has been growing interest in the discovery of small molecules that amplify the kinase activity of PINK1. We herein report the design, synthesis, serum stability and hydrolysis of four kinetin riboside ProTides. These ProTides, along with kinetin riboside, activ...

A molecular barbiturate messenger, which is reversibly released/captured by a photoswitchable artificial molecular receptor, is shown to act as an effector to control ring gliding on a distant hydrogen-bonding [2]rotaxane. Thus, light-driven chemical communication governing the operation of a remote molecular machine is demonstrated using an inform...

A new series of chiral ferrocene derivatives containing both a hydroxyalkyl group and a thyminyl group on one cyclopentadienyl ring have been synthesised in order to probe structure activity relationships in cancer cell-line cytotoxicities. Stereoisomers of enantiomeric pairs of these so-called ferronucleosides have been studied and characterised b...

Scaffold design, synthesis and application is relevant for biomedical research. For example, multivalent interactions, such as those between cell surface glycoproteins and lectins can influence the potency and duration of signalling. The spacing between carbohydrates on their native protein scaffold could be important. Herein, the coiled coil desig...

A macrocyclic ring comprising multiple hydrogen-bonding sites as well as metal-chelating sites is shown to play the role of ligand in active templated, copper-catalysed [2]rotaxane formation via Huisgen and Glaser reactions. The crystallographic structure and copper ion binding studies are provided for the free macrocycle, along with molecular mode...

The direct incorporation of macrocyclic cyclidene complexes into DNA via automated synthesis results in a new family of metal-functionalized DNA derivatives that readily demonstrate their utility through the ability of one copper(II)-containing strand to distinguish electrochemically between all four canonical DNA nucle-obases at a single site with...

The ability to discriminate between epigenetic variants in DNA is a necessary tool if we are to increase our understanding of the roles that they play in various biological processes and medical conditions. Herein it is demonstrated how a simple two-step fluorescent probe assay can be used to differentiate all three major epigenetic variants of cyt...

The field of synthetic biology includes studies that aim to develop new materials and devices from biomolecules. In recent years much work has been carried out using a range of biomolecular chassis including α-helical coiled coils, α-sheet amyloids and even viral particles. In this work we show how hybrid bionanoparticles can be produced from a vir...

The unprecedented use of anthracene photodimerization within a protein or peptide system is explored through its incorporation into a DNA-binding peptide, derived from the GCN4 transcription factor. This study demonstrates an effective and dynamic interplay between a photoreaction and a peptide-DNA assembly, with each process able to exert control...

A new series of chiral ureas containing one or two redox-active ferrocene units was synthesised and studied in order to investigate the effect of planar chirality and central chirality on electrochemical chiral sensing. Binding of chiral carboxylate anions in organic solvents through H-bond formation caused a negative shift in the potentials of the...

A [2]rotaxane, whose thread component comprises a central dibenzylammonium group and 9-alkoxyanthracene stoppers and is hosted by a 24-dibenzo-8-crown bead, undergoes an efficient photocatenation step resulting in a [2]rotaxane-to-[2]catenane topology interconversion via a fully reversible [4π+4π] photocyclomerization of terminal anthracene groups.

An overview of representative members of the wealth of supramolecular host:guest complexes and polymers formed through association of complementary hydrogen-bonding motifs comprising barbiturates (or structurally related cyanurates in specific cases) and Hamilton-type, bis(amidopyridine) receptor motifs, which offer strong selective binding in non-...

Photoirradiation of a hydrogen-bonded molecular complex comprising acyclic components, namely a stoppered thread (1) with a central barbiturate motif and an optimized doubly anthracene-terminated acyclic Hamilton-like receptor (2b), leads to an interlocked architecture, which was isolated and fully characterized. The sole isolated interlocked photo...

Examples of organometallic compounds as nucleoside analogues are rare within the field of medicinal bioorganometallic chemistry. We report on the synthesis and properties of two chiral ferrocene derivatives containing both a nucleobase and a hydroxyalkyl group. These so-called ferronucleosides show promising anticancer activity, with cytostatic stu...

Förster resonance energy transfer (FRET) technology relies on the close proximity of two compatible fluorophores for energy transfer. Tagged (Cy3 and Cy5) complementary DNA strands forming a stable duplex and a doubly-tagged single strand were shown to demonstrate FRET outside of a cellular environment. FRET was also observed after transfecting the...

Interlocked structures containing the classic Hamilton barbiturate binding motif comprising two 2,6-diamidopyridine units are reported for the first time. Stable [2]-rotaxanes can be accessed either through hydrogen-bonded preorganization by a barbiturate thread followed by a Cu(+)-catalyzed "click" stoppering reaction or by a Cu(2+)-mediated Glase...

This review summarizes the field of bioorganometallic nucleic acid chemistry, with a specific focus on various synthetic approaches for utilizing organometallic groups, in particular ferrocene, as functional tags for existing nucleic acids or as components for novel nucleic acid analogues.

The synthesis of an anthracene-bearing photoactive barbituric acid receptor and its subsequent grafting onto azide-terminated alkanethiol/Au self-assembled monolayers by using an Cu(I) -catalyzed azide-alkyne reaction is reported. Monolayer characterization using contact-angle measurements, electrochemistry, and spectroscopic ellipsometry indicate...

Rates of pyramidal motion in an aziridine are controlled by reversible trans to cis photoisomerisation of an azobenzene unit attached to the ring nitrogen atom. The dynamics of the inversion process and activation parameters are derived by variable temperature NMR, and are supported by ab initio calculations.

A method for probing the strength of B-N dative bonds is reported. The activation parameters for nitrogen inversion in a series of azetidines tethered to boronate esters have been quantified by VT-NMR and the measured barriers correlated with data obtained by B NMR, X-ray crystallography and MP2 calculations.

The design, synthesis and electrochemical behaviour of an oligomer consisting of linked thymine-functionalised ferrocene units are reported, which, as a so-called form of ferrocene nucleic acid (FcNA), acts as a structural mimic of DNA.

The synthesis and in-depth characterisation including X-ray crystallography of a new hydroxy derivative of bis(2-pyridylcarbonyl)amine Hbpca, namely N-(3-hydroxypicolinoyl)picolinamide (Hbpca-OH), as well as two ferrocenyl derivatives of Hbpca-OH, namely 2-(picolinoylcarbamoyl)pyridin-3-yl ferrocenoate (HL1) and bis(2-(picolinoylcarbamoyl)pyridin-3...

Modified DNA strands undergo a reversible light-induced reaction involving the intramolecular photodimerization of two appended anthracene tags. The photodimers exhibit markedly different binding behavior toward a complementary strand that depends on the number of bases between the modified positions. By preforming the duplex, photochromism can be...

This review focuses on supramolecular receptors designed for the detection of guest species in solution by virtue of their incorporation of a redox-active group, which is able to electrochemically respond to a binding event. The redox-active group is normally covalently attached in close proximity to the binding site in order to maximize the redox...

Single nucleotide polymorphisms within a sequence of a gene associated with prostate cancer were identified using oligodeoxynucleotide probe sequences bearing internal anthracene fluorophores proximal to the SNP site. Depending upon the nature of the synthesised target sequences, probe-target duplex formation could lead to enhanced or attenuated fl...

Four organometallic nucleobases have been prepared and characterized, each consisting of a disubstituted ferrocene unit connected through either a conjugated or saturated linker group to adenine or thymine nucleobases. Their assembly behavior has been studied in the solid state via X-ray crystallography, revealing intermolecular H-bonded arrays. Th...

A fluorescent DNA probe containing an anthracene group attached via an anucleosidic linker can identify all four DNA bases at a single site as well as the epigenetic modification C/5-MeC via a hybridisation sensing assay.

By tuning the frontier orbital energies through selective halogenation of the periphery of the organic framework, new light harvesting electron acceptors based on boron subphthalocyanine chloride (SubPc) have been made. Planar heterojunction organic photovoltaics made using a Cl 6-SubPc acceptor deliver an exceptionally high open-circuit voltage (∼...

A fluorescent anthracene-tagged DNA probe has been shown to respond to various DNA sequences by changes to its emission signal upon duplex formation. The fluorescence response for duplexes containing a single mismatch near the anthracene site has been found to be very sensitive to its composition, with the emission signal increasing for a CA mismat...

Die Geschwindigkeit der N-Inversion in Aziridinderivaten hängt von intramolekularen Wechselwirkungen zwischen den funktionellen Gruppen ab, was die Ermittlung von spezifischen nichtkovalenten Wechselwirkungen ermöglicht. Das ortho-substituierte Pyridin invertiert schneller, weil es im Übergangszustand eine intramolekulare Amid-Pyridin-Wasserstoffbr...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A series of polythiaarene derivatives has been synthesised and their redox properties studied. The charge stabilizing effect of the aryl sulfide groups that surround the central aromatic core promotes nucleophilic substitution and markedly facilitates radical anion formation, leading to remarkably mild reduction potentials. Polythiaarene units may...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A chiral ferrocene-based boronic acid interacts with (R)- and (S)-Binol to form two complexes that exhibit significantly different ferrocene-based electrode potentials. This difference in redox behavior can be exploited to demonstrate in principle how high levels of enantiomeric excess in a mixture of enantiomers can be quantified and read-out usin...

Isolipoic acid, a symmetrical and achiral isomer of the commonly used alpha-lipoic acid, has previously been overlooked as a tether group for the formation of self-assembled monolayers (SAMs). Here its ready synthesis through a new route and its functionalization with ferrocenyl groups for redox-active SAM formation on gold electrodes are described...

Two new ligand derivatives of ferrocene, namely N-4-[3,5-di-(2-pyridyl)-1,2,4-triazoyl]ferrocene carbimine (L1) and N-4-[3,5-di-(2-pyridyl)-1,2,4-triazoyl]ferrocene carbamide (L2), were synthesised in good yields by reacting the known compound 3,5-di-pyridine-2-yl-[1,2,4]triazol-4-ylamine (1) with ferrocenecarbaldehyde and chlorocarbonyl ferrocene,...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The organizational effect induced by noncovalent interactions such as hydrogen-bonding (H-B) and metal ion complexation on photoinduced processes is discussed. These include the intermolecular photodimerization of cinnamates, which is shown to occur under topochemical control within the supramolecular assemblies, and the intramolecular photodimeriz...

Planar chirality associated with the ferrocene in ferrocenyl oximes and hydrazones bearing chiral auxiliaries effectively competes with or overrides the normally excellent stereocontrol afforded by the auxiliary in determining the diastereoselectivity of addition to the C=N bond.

A novel organometallic receptor binds anions in solution and in the solid state, with complexes stabilised through a series of C-HX interactions, as evidenced by 1H NMR spectroscopy, X-ray crystallography and computational models.

The syntheses of a series of chiral ureas containing the redox-active ferrocene group are described. Each of these bind chiral carboxylates in organic solvents through hydrogen-bonding interactions, as evidenced by spectroscopic and cyclic voltammetry measurements, the latter allowing these guests to be electrochemically sensed in solution. The ena...

The molecular motion associated with atomic inversion at an aziridine nitrogen can be essentially halted by metal complexation; addition of a second chemical input that decomplexes the metal from the aziridine restores fast inversion (k=40 s(-1) at 303 K).

Directed Michaelis–Arbuzov reactions of support-bound internucleotide O-benzyl- or O-methyl-phosphite triesters with meta-phenylazobenzylamine or alkane-/glycol-linked α,ω-diamines were effected in the presence of iodine. The corresponding tritylated phosphoramidate-linked 11-mers were fully deprotected and released from the support under standard...

The structure of the title symmetrically disubstituted acridine derivative [systematic name: N,N′-(acridine-4,5-diyldimethyl­ene)bis­phthalimide], C31H19N3O4, has been determined at 120 K using synchrotron radiation. The mol­ecule contains a planar acridine and two planar phthalimide fragments. The pseudo-torsion angle N—C⋯C—N between the phthalimi...

The structure of the title symmetrically disubstituted acridine derivative [systematic name: N,N′-(acridine-4,5-diyldimethyl­ene)bis­phthalimide], C31H19N3O4, has been determined at 120 K using synchrotron radiation. The mol­ecule contains a planar acridine and two planar phthalimide fragments. The pseudo-torsion angle N—C⋯C—N between the phthalimi...

A novel anthracene-tagged oligonucleotide can discriminate between a fully-matched DNA target sequence and one with a single mismatching base-pair through a remarkable difference in fluorescence emission intensity upon duplex formation.

The dynamics of pyramidal nitrogen inversion can be controlled by reversible redox switching in trans-2,3-diphenylaziridines bearing a suitable 1,4-naphthaquinone substituent. In the reduced form, an intramolecular H-bond significantly raises the inversion barrier slowing this molecular motion by >50-fold. The experimental findings are further supp...