Publications
177 results found
Steinmüller SAM, Odaybat M, Galli G, et al., 2024, Arylazobenzimidazoles: versatile visible-light photoswitches with tuneable Z-isomer stability., Chem Sci, Vol: 15, Pages: 5360-5367, ISSN: 2041-6520
Benzimidazole heterocycles are of great importance in medicinal chemistry due to their applicability to a wide range of pharmacological targets, therefore representing a prototypical "privileged structure". In photopharmacology, azoheteroarene photoswitches have emerged as valuable tools for a variety of applications due to the high tuneability of their photophysical properties. Benzimidazole-based photoswitches could therefore enable the optically-controlled investigation of many pharmacological targets and find application in materials science. Here we report a combined experimental and computational investigation of such arylazobenzimidazoles, which allowed us to identify derivatives with near-quantitative bidirectional photoswitching using visible light and highly tuneable Z-isomer stability. We further demonstrate that arylazobenzimidazoles bearing a free benzimidazole N-H group not only exhibit efficient bidirectional photoswitching, but also excellent thermal Z-isomer stability, contrary to previously reported fast-relaxing Z-isomers of N-H azoheteroarenes. Finally, we describe derivatives which can be reversibly isomerized with cyan and red light, thereby enabling significantly "red-shifted" photocontrol over prior azoheteroarenes. The understanding gained in this study should enable future photopharmacological efforts by employing photoswitches based on the privileged benzimidazole structure.
Furlan F, Moreno-Naranjo JM, Gasparini N, et al., 2024, Chiral materials and mechanisms for circularly polarized light-emitting diodes, Nature Photonics, ISSN: 1749-4885
Circularly polarized (CP) light-emitting diodes (LEDs) hold great potential for next-generation technologies, from efficient photonic to room-temperature quantum devices. Chiral materials enable the generation of CP electroluminescence in LEDs through several different mechanisms, depending on the choice of material and device architecture. Here we summarize the mechanisms that give rise to CP electroluminescence in state-of-the-art materials, including organic small molecules, polymers, inorganic complexes and hybrid halide perovskites. We explore how the device architecture can be used to control the chiroptical properties and device performance, and suggest improvements to maximize the efficiency and dissymmetry factor of future CP LEDs.
Brand MC, Trowell HG, Fuchter MJ, et al., 2024, Incorporating photoresponses into porous liquids, Chemistry: A European Journal, Vol: 30, Pages: 1-7, ISSN: 0947-6539
Porous liquids combine the properties of a porous solid with those of a liquid, creating a porous flowable media. Since their discovery, these materials have gathered widespread interest within the scientific community, with substantial numbers of new systems being discovered, often with a focus on increasing the pore volume and gas capacity. Which begs the question, what does the future hold for porous liquids? Recently, the first examples of photoresponsive porous liquids have emerged, allowing changes in porosity to be observed under UV irradiation. Here, we expand on our previous report of photoresponsive porous liquids and explore the conceptualisation of responsive porous liquids and how these materials could be developed with the ability to respond to light, thereby offering a potential mechanism of controllable uptake and release in these systems. This concept article summarises different approaches that could be used to incorporate a photoresponse in a porous liquid before discussing recently reported systems, alongside important factors to consider in their design. Finally, by taking inspiration from the methods used to translate porous solids into the liquid state, combined with the field of photoresponsive materials, we discuss potential strategies that could be employed to realise further examples of photoresponsive porous liquids.
Shioukhi I, Batchu H, Schwartz G, et al., 2024, Helitwistacenes-combining lateral and longitudinal helicity results in solvent-induced inversion of circularly polarized light, Angewandte Chemie International Edition, Vol: 63, ISSN: 1433-7851
Helicity is expressed differently in ortho- and para-fused acenes-helicenes and twistacenes, respectively. While the extent of helicity is constant in helicenes, it can be tuned in twistacenes, and the handedness of flexible twistacenes is often determined by more rigid helicenes. Here, we combine helicenes with rigid twistacenes consisting of a tunable degree of twisting, forming helitwistacenes. While the X-ray structures reveal that the connection does not affect the helicity of each moiety, their electronic circular dichroism (ECD) and circularly polarized luminescence (CPL) spectra are strongly affected by the helicity of the twistacene unit, resulting in solvent-induced sign inversion. ROESY NMR and TD-DFT calculations support this observation, which is explained by differences in the relative orientation of the helicene and twistacene moieties.
Constantin TA, Varela-Carver A, Greenland KK, et al., 2024, Correction: The CDK7 inhibitor CT7001 (Samuraciclib) targets proliferation pathways to inhibit advanced prostate cancer., Br J Cancer, Vol: 130
Gedeon C, Del Rio N, Furlan F, et al., 2024, Rational design of new conjugated polymers with main chain chirality for efficient optoelectronic devices: carbo[6]helicene and indacenodithiophene copolymers as model compounds, Advanced Materials, ISSN: 0935-9648
The unique properties of conjugated polymers (CPs) in various optoelectronic applications are mainly attributed to their different self-assembly processes and superstructures. Various methods are utilized to tune and control CP structure and properties with less attention paid to the use of chirality. CPs with main chain chirality are rare and their microscopic and macroscopic properties are still unknown. In this work, the first experimental results are provided along these lines by synthesizing a series of racemic and enantiopure CPs containing statistical and alternating carbo[6]helicene and indacenodithiophene moieties and evaluating their microscopic (optical, energy levels) and macroscopic properties (hole mobilities, photovoltaic performance). It is demonstrated that a small statistical insertion of either the racemic or enantiopure helicene into the polymer backbone finely tunes the microscopic and macroscopic properties as a function of the statistical content. The microscopic properties of the enantiopure versus the racemic polymers with the same helicene loading remain similar. On the contrary, the macroscopic properties, and more interestingly those between the two enantiomeric forms, are altered as a function of the statistical content. Once incorporated into a solar cell device, these chiral CPs display better performance in their enantiopure versus racemic forms.
Sampieri A, Padilla-Flores T, Thawani AR, et al., 2023, The conducting state of TRPA1 modulates channel lateral mobility, Cell Calcium, Vol: 116, ISSN: 0143-4160
We have studied Danio rerio (Zebrafish) TRPA1 channel using a method that combines single channel electrophysiological and optical recordings to evaluate lateral mobility and channel gating simultaneously in single channels. TRPA1 channel activation by two distinct chemical ligands: allyl isothiocyanate (AITC) and TRPswitch B, results in substantial reduction of channel lateral mobility at the plasma membrane. Incubation with the cholesterol sequestering agent methyl-β-cyclodextrin (MβCD), prevents the reduction on lateral mobility induced by the two chemical agonists. This results strongly suggest that the open conformation of TRPA1 modulates channel lateral mobility probably by facilitating the insertion of the channel into cholesterol-enriched domains at the plasma membrane.
Minion L, Wade J, Moreno-Naranjo JM, et al., 2023, Insights into the origins of inverted circular dichroism in thin films of a chiral side chain polyfluorene, CHIRALITY, Vol: 35, Pages: 817-825, ISSN: 0899-0042
Reyser T, Paloque L, Nguyen M, et al., 2023, Epidrugs as Promising Tools to Eliminate Plasmodium falciparum Artemisinin-Resistant and Quiescent Parasites., Pharmaceutics, Vol: 15, ISSN: 1999-4923
The use of artemisinin and its derivatives has helped reduce the burden of malaria caused by Plasmodium falciparum. However, artemisinin-resistant parasites are able, in the presence of artemisinins, to stop their cell cycles. This quiescent state can alter the activity of artemisinin partner drugs leading to a secondary drug resistance and thus threatens malaria eradication strategies. Drugs targeting epigenetic mechanisms (namely epidrugs) are emerging as potential antimalarial drugs. Here, we set out to evaluate a selection of various epidrugs for their activity against quiescent parasites, to explore the possibility of using these compounds to counter artemisinin resistance. The 32 chosen epidrugs were first screened for their antiplasmodial activity and selectivity. We then demonstrated, thanks to the specific Quiescent-stage Survival Assay, that four epidrugs targeting both histone methylation or deacetylation as well as DNA methylation decrease the ability of artemisinin-resistant parasites to recover after artemisinin exposure. In the quest for novel antiplasmodial drugs with new modes of action, these results reinforce the therapeutic potential of epidrugs as antiplasmodial drugs especially in the context of artemisinin resistance.
Gemen J, Church J, Ruoko T-P, et al., 2023, Disequilibrating azobenzenes by visible-light sensitization under confinement, Science, Vol: 381, Pages: 1357-1363, ISSN: 0036-8075
Photoisomerization of azobenzenes from their stable E isomer to the metastable Z state is the basis of numerous applications of these molecules. However, this reaction typically requires ultraviolet light, which limits applicability. In this study, we introduce disequilibration by sensitization under confinement (DESC), a supramolecular approach to induce the E-to-Z isomerization by using light of a desired color, including red. DESC relies on a combination of a macrocyclic host and a photosensitizer, which act together to selectively bind and sensitize E-azobenzenes for isomerization. The Z isomer lacks strong affinity for and is expelled from the host, which can then convert additional E-azobenzenes to the Z state. In this way, the host–photosensitizer complex converts photon energy into chemical energy in the form of out-of-equilibrium photostationary states, including ones that cannot be accessed through direct photoexcitation.
Griffiths K, Greenfield JL, Halcovitch NR, et al., 2023, Systematic Investigation into the Photoswitching and Thermal Properties of Arylazopyrazole-based MOF Host-Guest Complexes, CRYSTAL GROWTH & DESIGN, Vol: 23, Pages: 7044-7052, ISSN: 1528-7483
Constantin TA, Varela-Carver A, Greenland KK, et al., 2023, The CDK7 inhibitor CT7001 (Samuraciclib) targets proliferation pathways to inhibit advanced prostate cancer, British Journal of Cancer, Vol: 128, Pages: 2326-2337, ISSN: 0007-0920
BACKGROUND: Current strategies to inhibit androgen receptor (AR) are circumvented in castration-resistant prostate cancer (CRPC). Cyclin-dependent kinase 7 (CDK7) promotes AR signalling, in addition to established roles in cell cycle and global transcription, providing a rationale for its therapeutic targeting in CRPC. METHODS: The antitumour activity of CT7001, an orally bioavailable CDK7 inhibitor, was investigated across CRPC models in vitro and in xenograft models in vivo. Cell-based assays and transcriptomic analyses of treated xenografts were employed to investigate the mechanisms driving CT7001 activity, alone and in combination with the antiandrogen enzalutamide. RESULTS: CT7001 selectively engages with CDK7 in prostate cancer cells, causing inhibition of proliferation and cell cycle arrest. Activation of p53, induction of apoptosis, and suppression of transcription mediated by full-length and constitutively active AR splice variants contribute to antitumour efficacy in vitro. Oral administration of CT7001 represses growth of CRPC xenografts and significantly augments growth inhibition achieved by enzalutamide. Transcriptome analyses of treated xenografts indicate cell cycle and AR inhibition as the mode of action of CT7001 in vivo. CONCLUSIONS: This study supports CDK7 inhibition as a strategy to target deregulated cell proliferation and demonstrates CT7001 is a promising CRPC therapeutic, alone or in combination with AR-targeting compounds.
Crassous J, Fuchter MJ, Freedman DE, et al., 2023, Materials for chiral light control, NATURE REVIEWS MATERIALS, Vol: 8, Pages: 365-371, ISSN: 2058-8437
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- Citations: 10
Shi W, Zhuang Q, Zhou R, et al., 2023, Enantiomerically Pure Fullerenes as a Means to Enhance the Performance of Perovskite Solar Cells, ADVANCED ENERGY MATERIALS, Vol: 13, ISSN: 1614-6832
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- Citations: 3
Sbirkov Y, Schenk T, Kwok C, et al., 2023, Dual inhibition of EZH2 and G9A/GLP histone methyltransferases by HKMTI-1-005 promotes differentiation of acute myeloid leukemia cells, FRONTIERS IN CELL AND DEVELOPMENTAL BIOLOGY, Vol: 11, ISSN: 2296-634X
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- Citations: 1
Yahiya S, Saunders CN, Hassan S, et al., 2023, A novel class of sulphonamides potently block malaria transmission by targeting a Plasmodium vacuole membrane protein, Disease Models & Mechanisms, Vol: 16, Pages: 1-20, ISSN: 1754-8403
Phenotypic cell-based screens are critical tools for discovering candidate drugs for development, yet identification of the cellular target and mode of action of a candidate drug is often lacking. Using an imaging-based screen, we recently discovered an N-[(4-hydroxychroman-4-yl)methyl]-sulphonamide (N-4HCS) compound, DDD01035881, that blocks male gamete formation in the malaria parasite life cycle and subsequent transmission of the parasite to the mosquito with nanomolar activity. To identify the target(s) of DDD01035881, and of the N-4HCS class of compounds more broadly, we synthesised a photoactivatable derivative, probe 2. Photoaffinity labelling of probe 2 coupled with mass spectrometry identified the 16 kDa Plasmodium falciparum parasitophorous vacuole membrane protein Pfs16 as a potential parasite target. Complementary methods including cellular thermal shift assays confirmed that the parent molecule DDD01035881 stabilised Pfs16 in lysates from activated mature gametocytes. Combined with high-resolution, fluorescence and electron microscopy data, which demonstrated that parasites inhibited with N-4HCS compounds phenocopy the targeted deletion of Pfs16 in gametocytes, these data implicate Pfs16 as a likely target of DDD01035881. This finding establishes N-4HCS compounds as being flexible and effective starting candidates from which transmission-blocking antimalarials can be developed in the future.
Wan L, Yizhou L, Fuchter M, et al., 2023, Anomalous circularly polarized light emission in organic light-emitting diodes caused by orbital-momentum locking, Nature Photonics, Vol: 17, Pages: 193-199, ISSN: 1749-4885
Chiral circularly polarized (CP) light is central to many photonic technologies, from optical communication of spin information to novel display and imaging technologies. As such, there has been significant effort in the development of chiral emissive materials that allow for the emission of strongly dissymmetric CP light from organic light-emitting diodes (OLEDs). A consensus for chiral emission in such devices is that the molecular chirality of the active layer determines the favored light handedness of CP emission, regardless of the light-emitting direction. Here, we discover that, unconventionally, oppositely propagating CP light exhibits opposite handedness and reversing the current-flow in OLEDs also switches the handedness of the emitted CP light. This direction-dependent CP emission boosts the net polarization rate by orders of magnitude by resolving an established issue in CP-OLEDs, where the CP light reflected by the back electrode typically erodes the measured dissymmetry. Through detailed theoretical analysis, we assign this anomalous CP emission to a ubiquitous topological electronic property in chiral materials, namely the orbital-momentum locking. Our work paves the way to design new chiroptoelectronic devices and probes the close connections between chiral materials, topological electrons, and CP light in the quantum regime.
Pilgrim BS, Slater A, Collins B, et al., 2022, MASC 2022: What challenges and opportunities do supramolecular chemists face in coming years?, CELL REPORTS PHYSICAL SCIENCE, Vol: 3
Rushworth JL, Thawani AR, Fajardo-Ruiz E, et al., 2022, [5]-Helistatins: Tubulin-Binding Helicenes with Antimitotic Activity, JACS AU, Vol: 2, Pages: 2561-2570
Griffiths R-R, Greenfield JL, Thawani AR, et al., 2022, Data-driven discovery of molecular photoswitches with multioutput Gaussian processes, CHEMICAL SCIENCE, Vol: 13, Pages: 13541-13551, ISSN: 2041-6520
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- Citations: 4
Ward MD, Shi W, Gasparini N, et al., 2022, Best practices in the measurement of circularly polarised photodetectors (vol 10, pg 10452, 2022), JOURNAL OF MATERIALS CHEMISTRY C, ISSN: 2050-7526
Tyagi G, Greenfield JL, Jones BE, et al., 2022, Light responsiveness and assembly of arylazopyrazole-based surfactants in neat and mixed CTAB micelles, JACS Au, Vol: 2, Pages: 2670-2677, ISSN: 2691-3704
The self-assembly of an arylazopyrazole-based photosurfactant (PS), based on cetyltrimethylammonium bromide (CTAB), and its mixed micelle formation with CTAB in aqueous solution was investigated by small angle neutron and X-ray scattering (SANS/SAXS) and UV–vis absorption spectroscopy. Upon UV light exposure, PS photoisomerizes from E-PS (trans) to Z-PS (cis), which transforms oblate ellipsoidal micelles into smaller, spherical micelles with larger shell thickness. Doping PS with CTAB resulted in mixed micelle formation at all stoichiometries and conditions investigated; employing selectively deuterated PS, a monotonic variation in scattering length density and dimensions of the micellar core and shell is observed for all contrasts. The concentration- and irradiance-dependence of the E to Z configurational transition was established in both neat and mixed micelles. A liposome dye release assay establishes the enhanced efficacy of photosurfactants at membrane disruption, with E-PS exhibiting a 4-fold and Z-PS a 10-fold increase in fluorescence signal with respect to pure CTAB. Our findings pave the way for external triggering and modulation of the wide range of CTAB-based biomedical and material applications.
Wade J, Salerno F, Kilbride R, et al., 2022, Controlling anisotropic properties by manipulating the orientation of chiral small molecules, Nature Chemistry, Vol: 14, Pages: 1383-1389, ISSN: 1755-4330
Chiral π-conjugated molecules bring new functionality to technological applications and represent an exciting, rapidly expanding area of research. Their functional properties, such as the absorption and emission of circularly polarised light or the transport of spin-polarised electrons, are highly anisotropic. As a result, the orientation of chiral molecules criticallydetermines the functionality and efficiency of chiral devices. Here we present a strategy to control the orientation of a small chiral molecule (2,2’-dicyano[6]helicene, CN6H): the use of organic and inorganic templating layers. Such templating layers can either force CN6H molecules to adopt a face-on orientation and self-assemble into upright supramolecular columns oriented with their helical axis perpendicular to the substrate, or an edge-onorientation with parallel-lying supramolecular columns. Through such control, we show that low- and high-energy chiroptical responses can be independently ‘turned on’ or ‘turned off’. The templating methodologies described here provide a simple way to engineer orientational control, and by association, anisotropic functional properties of chiral molecular systems for a range of emerging technologies.
Gonzalez A, Odaybat M, Le M, et al., 2022, Photocontrolled Energy Storage in Azobispyrazoles with Exceptionally Large Light Penetration Depths, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, Vol: 144, Pages: 19430-19436, ISSN: 0002-7863
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- Citations: 15
Furlan F, Nodari D, Palladino E, et al., 2022, Tuning Halide Composition allows low dark current perovskite photodetectors with high specific detectivity, Advanced Optical Materials, Vol: 10, Pages: 1-8, ISSN: 2195-1071
Tuning halide composition in perovskites is a powerful approach demonstrated to enhance the performance of perovskite photovoltaic devices where such compositional modifications drive improvements in open-circuit voltage (Voc) and a reduction in nonradiative voltage losses. Similarly, photodetectors (PDs) operate as light to current conversion devices hence it is relevant to investigate whether performance enhancements can be achieved by similar strategies. Herein, perovskite PDs are fabricated with an inverted photodiode configuration based on a MAPb(I1-xBrx)3 perovskite (MA = methylammonium) active layer over the x = 0–0.25 composition range. Interestingly, it has been found that increasing the Br content up to 0.15 (15%) leads to a significant reduction in dark current (Jd), with values as low as 1.3 × 10−9 A cm−2 being achieved alongside a specific detectivity of 8.7 × 1012 Jones. Significantly, it has been observed an exponential relationship between the Jd of devices and their Voc over the 0–15% Br range. The superior performances of the 15% Br-containing devices are attributed to the reduction of trap states, a better charge extraction of photogenerated carriers, and an improvement in photoactive layer morphology and crystallinity.
Perez NH, Sherin PS, Posligua V, et al., 2022, Emerging properties from mechanical tethering within a post-synthetically functionalised catenane scaffold, Chemical Science, Vol: 13, Pages: 11368-11375, ISSN: 2041-6520
Maintaining close spatial proximity of functional moieties within molecular systems can result in fascinating emergent properties. Whilst much work has been done on covalent tethering of functional units for myriad applications, investigations into mechanically linked systems are relatively rare. Formation of the mechanical bond is usually the final step in the synthesis of interlocked molecules, placing limits on the throughput of functionalised architectures. Herein we present the synthesis of a bis-azide [2]catenane scaffold that can be post-synthetically modified using CuAAC ‘click’ chemistry. In this manner we have been able to access functionalised catenanes from a common precursor and study the properties of electrochemically active, emissive and photodimerisable units within the mechanically interlocked system in comparison to non-interlocked analogues. Our data demonstrates that the greater (co-)conformational flexibility that can be obtained with mechanically interlocked systems compared to traditional covalent tethers paves the way for developing new functional molecules with exciting properties.
Zhang Q, Kounde C, Mondal M, et al., 2022, Light-mediated multi-target protein degradation using arylazopyrazole photoswitchable PROTACs (AP-PROTACs), Chemical Communications, Vol: 58, Pages: 10933-10936, ISSN: 1359-7345
Light-activable spatiotemporal control of PROTAC-induced protein degradation was achieved with novel arylazopyrazole photoswitchable PROTACs (AP-PROTACs). The use of a promiscuous kinase inhibitor in the design enables this unique photoswitchable PROTAC to selectively degrade four protein kinases together with on/off optical control using different wavelengths of light.
Ward MD, Shi W, Gasparini N, et al., 2022, Best practices in the measurement of circularly polarised photodetectors, JOURNAL OF MATERIALS CHEMISTRY C, Vol: 10, Pages: 10452-10463, ISSN: 2050-7526
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- Citations: 6
Yan H, Wade J, Wan L, et al., 2022, Enhancing hole carrier injection <i>via</i> low electrochemical doping on circularly polarized polymer light-emitting diodes, JOURNAL OF MATERIALS CHEMISTRY C, Vol: 10, Pages: 9512-9520, ISSN: 2050-7526
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- Citations: 8
Wan L, Wade J, Shi X, et al., 2022, Highly Efficient Inverted Circularly Polarized Organic Light Emitting Diodes (vol 12, pg 39471, 2020), ACS APPLIED MATERIALS & INTERFACES, Vol: 14, Pages: 27523-27523, ISSN: 1944-8244
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