E01-JEM ARM 200CF
E02-JEM ARM 300CF
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Diamond Proposal Number(s):
[29599]
Open Access
Abstract: Solar H2O2 produced by O2 reduction provides a green, efficient, and ecological alternative to the industrial anthraquinone process and H2/O2 direct-synthesis. We report efficient photocatalytic H2O2 production at a rate of 73.4 mM h–1 in the presence of a sacrificial donor on a structurally engineered catalyst, alkali metal-halide modulated poly(heptazine imide) (MX → PHI). The reported H2O2 production is nearly 150 and >4250 times higher than triazine structured pristine carbon nitride under UV–visible and visible light (≥400 nm) irradiation, respectively. Furthermore, the solar H2O2 production rate on MX → PHI is higher than most of the previously reported carbon nitride (triazine, tri-s-triazine), metal oxides, metal sulfides, and other metal–organic photocatalysts. A record high AQY of 96% at 365 nm and 21% at 450 nm was observed. We find that structural modulation by alkali metal-halides results in a highly photoactive MX → PHI catalyst which has a broader light absorption range, enhanced light absorption ability, tailored bandgap, and a tunable band edge position. Moreover, this material has a different polymeric structure, high O2 trapping ability, interlayer intercalation, as well as surface decoration of alkali metals. The specific C≡N groups and surface defects, generated by intercalated MX, were also considered as potential contributors to the separation of photoinduced electron–hole pairs, leading to enhanced photocatalytic activity. A synergy of all these factors contributes to a higher H2O2 production rate. Spectroscopic data help us to rationalize the exceptional photochemical performance and structural characteristics of MX → PHI.
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Jun 2022
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B18-Core EXAFS
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Diamond Proposal Number(s):
[29684]
Abstract: A Pt–Ni–Co catalyst was synthesized with Pt single atoms and atomic clusters (SAACs) dispersed over (Ni,Co)(OH)2 nanoparticles on a carbon matrix, which leads to high catalytic activity, up to 100% conversion, and selectivity in the hydrogenation of nitroaromatics under moderate conditions (H2 ∼ 1.0 MPa and ≤40 °C). A synergistically coordinated ensemble effect of the Pt SAACs is identified with the strongly polarized Pt single atoms preferentially adsorbing the −NO2 and the Pt clusters adsorbing and homolytically dissociating H2 molecules, and the H species then readily move to the adsorbed −NO2 group, overcoming a much reduced energy barrier on the (Ni,Co)(OH)2, enhancing the reaction rate by ca. 50 times. The approach not only reveals the coordinated ensemble catalysis mechanism of SAACs but also provides a strategy of developing highly efficient and selective catalysts by fine tuning of the electronic microenvironment from single atoms to atomic clusters co-located over a multimetallic substrate. The demonstrated case for nitroarenes can be readily applied for other species containing −NO2 or other easily hydrogenated groups (such as C═C, C≡N, and C═O).
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Jun 2022
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I24-Microfocus Macromolecular Crystallography
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Diamond Proposal Number(s):
[18598]
Open Access
Abstract: Bacterial cell division is a complex process requiring the coordination of multiple components to allow the appropriate spatial and temporal control of septum formation and cell scission. Peptidoglycan (PG) is the major structural component of the septum, and our recent studies in the human pathogen Staphylococcus aureus have revealed a complex, multistage PG architecture that develops during septation. Penicillin-binding proteins (PBPs) are essential for the final steps of PG biosynthesis; their transpeptidase activity links the peptide side chains of nascent glycan strands. PBP1 is required for cell division in S. aureus, and here, we demonstrate that it has multiple essential functions associated with its enzymatic activity and as a regulator of division. Loss of PBP1, or just its C-terminal PASTA domains, results in cessation of division at the point of septal plate formation. The PASTA domains can bind PG and thereby potentially coordinate the cell division process. The transpeptidase activity of PBP1 is also essential, but its loss leads to a strikingly different phenotype of thickened and aberrant septa, which is phenocopied by the morphological effects of adding the PBP1-specific β-lactam, meropenem. Together, these results lead to a model for septal PG synthesis where PBP1 enzyme activity is required for the characteristic architecture of the septum and PBP1 protein molecules enable the formation of the septal plate.
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Jun 2022
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I03-Macromolecular Crystallography
I04-1-Macromolecular Crystallography (fixed wavelength)
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Owen A.
Davis
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Kwai-Ming J.
Cheung
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Alfie
Brennan
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Matthew G.
Lloyd
,
Matthew J.
Rodrigues
,
Olivier A.
Pierrat
,
Gavin W.
Collie
,
Yann-Vai
Le Bihan
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Rosemary
Huckvale
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Alice C.
Harnden
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Ana
Varela
,
Michael D.
Bright
,
Paul
Eve
,
Angela
Hayes
,
Alan T.
Henley
,
Michael D.
Carter
,
P. Craig
Mcandrew
,
Rachel
Talbot
,
Rosemary
Burke
,
Rob
Van Montfort
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Florence I.
Raynaud
,
Olivia W.
Rossanese
,
Mirco
Meniconi
,
Benjamin R.
Bellenie
,
Swen
Hoelder
Open Access
Abstract: To identify new chemical series with enhanced binding affinity to the BTB domain of B-cell lymphoma 6 protein, we targeted a subpocket adjacent to Val18. With no opportunities for strong polar interactions, we focused on attaining close shape complementarity by ring fusion onto our quinolinone lead series. Following exploration of different sized rings, we identified a conformationally restricted core which optimally filled the available space, leading to potent BCL6 inhibitors. Through X-ray structure-guided design, combined with efficient synthetic chemistry to make the resulting novel core structures, a >300-fold improvement in activity was obtained by the addition of seven heavy atoms.
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Jun 2022
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I03-Macromolecular Crystallography
I04-1-Macromolecular Crystallography (fixed wavelength)
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Ina
Pöhner
,
Antonio
Quotadamo
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Joanna
Panecka-Hofman
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Rosaria
Luciani
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Matteo
Santucci
,
Pasquale
Linciano
,
Giacomo
Landi
,
Flavio
Di Pisa
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Lucia
Dello Iacono
,
Cecilia
Pozzi
,
Stefano
Mangani
,
Sheraz
Gul
,
Gesa
Witt
,
Bernhard
Ellinger
,
Maria
Kuzikov
,
Nuno
Santarem
,
Anabela
Cordeiro-Da-Silva
,
Maria P.
Costi
,
Alberto
Venturelli
,
Rebecca C.
Wade
Open Access
Abstract: The optimization of compounds with multiple targets is a difficult multidimensional problem in the drug discovery cycle. Here, we present a systematic, multidisciplinary approach to the development of selective antiparasitic compounds. Computational fragment-based design of novel pteridine derivatives along with iterations of crystallographic structure determination allowed for the derivation of a structure–activity relationship for multitarget inhibition. The approach yielded compounds showing apparent picomolar inhibition of T. brucei pteridine reductase 1 (PTR1), nanomolar inhibition of L. major PTR1, and selective submicromolar inhibition of parasite dihydrofolate reductase (DHFR) versus human DHFR. Moreover, by combining design for polypharmacology with a property-based on-parasite optimization, we found three compounds that exhibited micromolar EC50 values against T. brucei brucei while retaining their target inhibition. Our results provide a basis for the further development of pteridine-based compounds, and we expect our multitarget approach to be generally applicable to the design and optimization of anti-infective agents.
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Jun 2022
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I04-1-Macromolecular Crystallography (fixed wavelength)
I04-Macromolecular Crystallography
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Yuguang
Zhao
,
William
Mahy
,
Nicky J.
Willis
,
Hannah L.
Woodward
,
David
Steadman
,
Elliott D.
Bayle
,
Benjamin N.
Atkinson
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James
Sipthorp
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Luca
Vecchia
,
Reinis R.
Ruza
,
Karl
Harlos
,
Fiona
Jeganathan
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Stefan
Constantinou
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Artur
Costa
,
Svend
Kjær
,
Magda
Bictash
,
Patricia C.
Salinas
,
Paul
Whiting
,
Jean-Paul
Vincent
,
Paul V.
Fish
,
E. Yvonne
Jones
Diamond Proposal Number(s):
[16814]
Open Access
Abstract: The Wnt signaling suppressor Notum is a promising target for osteoporosis, Alzheimer’s disease, and colorectal cancers. To develop novel Notum inhibitors, we used an X-ray crystallographic fragment screen with the Diamond-SGC Poised Library (DSPL) and identified 59 fragment hits from the analysis of 768 data sets. Fifty-eight of the hits were found bound at the enzyme catalytic pocket with potencies ranging from 0.5 to >1000 μM. Analysis of the fragments’ diverse binding modes, enzymatic inhibitory activities, and chemical properties led to the selection of six hits for optimization, and five of these resulted in improved Notum inhibitory potencies. One hit, 1-phenyl-1,2,3-triazole 7, and its related cluster members, have shown promising lead-like properties. These became the focus of our fragment development activities, resulting in compound 7d with IC50 0.0067 μM. The large number of Notum fragment structures and their initial optimization provided an important basis for further Notum inhibitor development.
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Jun 2022
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I03-Macromolecular Crystallography
I04-Macromolecular Crystallography
I24-Microfocus Macromolecular Crystallography
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Abstract: Cannabidiol (CBD), is a major non-psychoactive compound isolated from the cannabis plant and has been associated with the treatment of a range of conditions which are often related to voltage-gated sodium ion channels (VGSCs). The aim of this research was to use X-ray crystallography to provide a detailed insight into the interactions which occur between CBD and the prokaryotic VGSC NavMs. CBD was found to bind at a novel site deep within the fenestration of NavMs, near the central hydrophobic cavity (Sait et al., 2020). Binding at this site would block sodium ion translocation, thus providing a mechanistic explanation for CBD’s channel inhibitory effects, which were validated via electrophysiology experiments performed on designed mutants in collaborative studies with the Ruben lab (Simon Fraser University).In addition, modelling studies conducted suggested why the closely related psychoactive compound tetrahydrocannabinol (THC) may have different binding interactions with VGSCs. Comparisons were also made between the proposed Transient Receptor Potential Cation Subfamily V member 2 (TRPV2) channel CBD binding site and the NavMs binding site. Finally, thermal melt circular dichroism spectroscopic experiments were carried out to explore CBD interactions with NavMs, which showed CBD does not affect NavMs stability during interaction. In summary, this study provides, for the first time, an insight into the possible mechanism underlying CBD interactions with sodium channels.
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Jun 2022
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I03-Macromolecular Crystallography
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Rosemary
Huckvale
,
Alice C.
Harnden
,
Kwai-Ming J.
Cheung
,
Olivier A.
Pierrat
,
Rachel
Talbot
,
Gary M.
Box
,
Alan T.
Henley
,
Alexis K.
De Haven Brandon
,
Albert E.
Hallsworth
,
Michael D.
Bright
,
Hafize Aysin
Akpinar
,
Daniel S. J.
Miller
,
Dalia
Tarantino
,
Sharon
Gowan
,
Angela
Hayes
,
Emma A.
Gunnell
,
Alfie
Brennan
,
Owen A.
Davis
,
Louise D.
Johnson
,
Selby
De Klerk
,
Craig
Mcandrew
,
Yann-Vai
Le Bihan
,
Mirco
Meniconi
,
Rosemary
Burke
,
Vladimir
Kirkin
,
Rob L. M.
Van Montfort
,
Florence I.
Raynaud
,
Olivia W.
Rossanese
,
Benjamin R.
Bellenie
,
Swen
Hoelder
Open Access
Abstract: The transcriptional repressor BCL6 is an oncogenic driver found to be deregulated in lymphoid malignancies. Herein, we report the optimization of our previously reported benzimidazolone molecular glue-type degrader CCT369260 to CCT373566, a highly potent probe suitable for sustained depletion of BCL6 in vivo. We observed a sharp degradation SAR, where subtle structural changes conveyed the ability to induce degradation of BCL6. CCT373566 showed modest in vivo efficacy in a lymphoma xenograft mouse model following oral dosing.
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Jun 2022
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I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[25166]
Open Access
Abstract: We present the synthesis of a novel binary metal oxide material: Ba7Mn4O15. The crystal structure has been investigated by high-resolution powder synchrotron X-ray diffraction in the temperature range of 100–300 K as well as by powder neutron diffraction at 10 and 80 K. This material represents an isostructural barium-substituted analogue of the layered material Sr7Mn4O15 that forms its own structural class. However, we find that Ba7Mn4O15 adopts a distinct magnetic ordering, resulting in a magnetoelectric ground state below 50 K. The likely magnetoelectric coupling mechanisms have been inferred from performing a careful symmetry-adapted refinement against the powder neutron diffraction experiments, as well as by making a comparison with the nonmagnetoelectric ground state of Sr7Mn4O15.
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Jun 2022
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I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[26090]
Abstract: Solid-state inorganic magnesium batteries are considered as potential high energy storage devices for the future. Here we present a series of magnesium borohydride tetrahydrofuran (THF) composites, Mg(BH 4 ) 2 · x THF(−MgO), 0 ≤ x ≤ 3, as solid-state electrolytes for magnesium batteries. Three new monoclinic compounds were identified, Mg(BH 4 ) 2 ·2/3THF ( Cc ), α-Mg(BH 4 ) 2 ·2THF ( P2 1 /c ) and β-Mg(BH 4 ) 2 ·2THF ( C2 ), and the detailed structures of α− and β−Mg(BH 4 ) 2 ·2THF are presented. The magnesium ionic conductivity of composites formed by these compounds were several orders of magnitude higher than that of the distinct compounds, x = 0, 2/3, 2, and 3. The nanocomposite stabilized by MgO nanoparticles (~50 nm), Mg(BH 4 ) 2 ·1.5THF−MgO(75 wt%), displayed the highest Mg 2+ conductivity, σ(Mg 2+ ) ~10 -4 S cm -1 at 70 °C, a high ionic transport number of t ion = 0.99, and cyclic voltammetry revealed an oxidative stability of ~1.2 V vs. Mg/Mg 2+ . The electrolyte was stable towards magnesium electrodes, which allowed for stable Mg plating/stripping for at least 100 cycles at 55 °C with a current density of 0.1 mA cm -2 . Finally, a proof-of-concept rechargeable solid-state magnesium battery was assembled with a magnesium metal anode, a TiS 2 cathode providing a maximum discharge capacity of 94.2 mAh g -1 , which corresponds to y = 0.2 in Mg y TiS 2.
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Jun 2022
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