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1.
Nature ; 609(7928): 709-717, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36131037

RESUMO

Additive manufacturing methods1-4 using static and mobile robots are being developed for both on-site construction5-8 and off-site prefabrication9,10. Here we introduce a method of additive manufacturing, referred to as aerial additive manufacturing (Aerial-AM), that utilizes a team of aerial robots inspired by natural builders11 such as wasps who use collective building methods12,13. We present a scalable multi-robot three-dimensional (3D) printing and path-planning framework that enables robot tasks and population size to be adapted to variations in print geometry throughout a building mission. The multi-robot manufacturing framework allows for autonomous three-dimensional printing under human supervision, real-time assessment of printed geometry and robot behavioural adaptation. To validate autonomous Aerial-AM based on the framework, we develop BuilDrones for depositing materials during flight and ScanDrones for measuring the print quality, and integrate a generic real-time model-predictive-control scheme with the Aerial-AM robots. In addition, we integrate a dynamically self-aligning delta manipulator with the BuilDrone to further improve the manufacturing accuracy to five millimetres for printing geometry with precise trajectory requirements, and develop four cementitious-polymeric composite mixtures suitable for continuous material deposition. We demonstrate proof-of-concept prints including a cylinder 2.05 metres high consisting of 72 layers of a rapid-curing insulation foam material and a cylinder 0.18 metres high consisting of 28 layers of structural pseudoplastic cementitious material, a light-trail virtual print of a dome-like geometry, and multi-robot simulations. Aerial-AM allows manufacturing in-flight and offers future possibilities for building in unbounded, at-height or hard-to-access locations.

3.
Phys Chem Chem Phys ; 25(27): 18011-18022, 2023 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-37377444

RESUMO

The MgO-CO2-H2O system have a variety of important industrial applications including in catalysis, immobilisation of radionuclides and heavy metals, construction, and mineralisation and permanent storage of anthropogenic CO2. Here, we develop a computational approach to generate phase stability plots for the MgO-CO2-H2O system that do not rely on traditional experimental corrections for the solid phases. We compare the predictions made by several dispersion-corrected density-functional theory schemes, and we include the temperature-dependent Gibbs free energy through the quasi-harmonic approximation. We locate the Artinite phase (Mg2CO3(OH)2·3H2O) within the MgO-CO2-H2O phase stability plot, and we demonstrate that this widely-overlooked hydrated and carbonated phase is metastable and can be stabilised by inhibiting the formation of fully-carbonated stable phases. Similar considerations may apply more broadly to other lesser known phases. These findings provide new insight to explain conflicting results from experimental studies, and demonstrate how this phase can potentially be stabilised by optimising the synthesis conditions.

4.
BMC Urol ; 23(1): 137, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37582745

RESUMO

BACKGROUND: Lymph node metastasis is the main determinant of survival in penile cancer patients. Conventionally clinical palpability is used to stratify patients to Inguinal Lymph node dissection (ILND) if clinically node positive (cN +) or Dynamic sentinel node biopsy (DSNB) if clinically node negative (cN0). Studies suggest a false negative rate (FNR) of around 10% (5-13%) for DSNB. To our knowledge there are no studies reporting harder end point of survival and outcomes of all clinically node positive (cN +) patients. We present our outcome data of all patients with penile cancer including false negative rates and survival in both DSNB and ILND groups. METHODS: One hundred fifty-eight consecutive patients (316 inguinal basins), who had lymph node surgery for penile cancer in a tertiary referral centre from Jan 2008 to 2018, were included in the study. All patients underwent ultrasound (US) ± fine needle aspiration cytology (FNAC) and then MRI/ CT, if needed, to stage their disease. We used combined clinical and radiological criteria (node size, architecture loss, irregular margins) to stratify patients to DSNB vs ILND as opposed to clinical palpability alone. RESULTS: 11.2% i.e., 27/241 inguinal basins had lymph node positive disease by DSNB. 54.9% i.e., 39/71 inguinal basins (IBs) had lymph node-positive disease by ILND. 4 inguinal basins with no tracer uptake in sentinel node scans are being monitored at patient's request and have not had any recurrences to date. With a mean follow-up of 65 months (range 24-150), the false-negative rate (FNR) for DSNB is 0%. Judicious uses of cross-sectional imaging necessitated ILND in 2 inguinal basins with non-palpable nodes and negative US with false positive rate of 6.3% (2/32) for ILND. The same cohort of DSNB patients might have had 11.1% (3/27) FNR if only palpability criteria was used. 43 (28%) patients who did require cross sectional imaging as per our criteria had a low node positive rate of 4.7% (p = 0.03). Mean cancer specific survival of all node-positive patients was 105 months. CONCLUSION: The performance of DSNB improved with enhanced radiological stratification of patients to either DSNB or ILND. We for the first time report the comprehensive outcome of all lymph node staging procedures in penile cancer.


Assuntos
Neoplasias Penianas , Masculino , Humanos , Neoplasias Penianas/diagnóstico por imagem , Neoplasias Penianas/cirurgia , Neoplasias Penianas/patologia , Seguimentos , Linfonodos/diagnóstico por imagem , Linfonodos/patologia , Biópsia de Linfonodo Sentinela/métodos , Excisão de Linfonodo , Estadiamento de Neoplasias
5.
BMC Public Health ; 22(1): 836, 2022 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-35473610

RESUMO

BACKGROUND: Parents frequently seek parental advice online and on social media; thus, these channels should be better utilized in child health interventions. The Parents in Child Nutrition Informing Community (PICNIC) program aims to facilitate peer-to-peer sharing of evidence-based child feeding information and support parents within their social networks. The present study aimed to explore web and social media analytics to evaluate reach and user engagement with the PICNIC online components. METHODS: Online user activity data from the PICNIC Facebook closed group and public Page were collected through Facebook Insights, and program-specific website traffic data through Google Analytics. Analytics data from Nov-2019 to April-2021 was evaluated through visualisation and summary statistics to obtain insights into program growth and current reach in Australia, compare demographics of audience reached through the online channels, and explore parents' use and engagement in PICNIC content. RESULTS: Results showed steady program growth in the 18 months of recruitment; participant numbers grew from 102 to 261 peer educators while the Facebook Page audience increased threefold, totalling 1615 followers. Intervention posts shared on Facebook (4-5 posts/week) typically reached only a portion of PICNIC Page followers each week, but also reached a wider audience through their friends. Throughout the evaluated period, Facebook users actively engaged in PICNIC posts, although the level of engagement varied considerably from post to post. Furthermore, results from this study suggest the strategy of directing potentially interested parents from social media to the website for program sign-up was successful. Finally, the explored data gave insights into users' availability, demographics and engagement, which will be used to inform refinement of the PICNIC website and social media strategies. CONCLUSIONS: Our findings confirm the benefits of using a peer education approach and existing social network channels to disseminate evidence-based child feeding information to parents. This study also demonstrates the usefulness of web and social media analytics to be used as part of a continuous evaluation for gaining insight to inform further development and improvement of program strategies. TRIAL REGISTRATION: The PICNIC project was retrospectively submitted for registration with the Australian New Zealand Clinical Trials Registry (ANZCTR), ACTRN12622000230752 (09/02/2022).


Assuntos
Mídias Sociais , Austrália , Criança , Humanos , Pais , Estudos Retrospectivos , Rede Social
6.
Bioorg Med Chem Lett ; 30(23): 127510, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-32898693

RESUMO

Here, we report the discovery of a new class of NPBWR1 antagonists identified from a fragment-based screen. Compound 1 (cAMP IC50 = 250 µM; LE = 0.29) emerged as an initial hit. Further optimization of 1 by SAR-by-catalogue and chemical modification produced 21a (cAMP IC50 = 30 nM; LE = 0.39) with a 6700-fold increase in potency from fragment 1. Somewhat surprisingly, Schild analysis of compound 21a suggested that in vitro inhibition of NPW-mediated effects on upon cAMP accumulation were saturable, and that compound 21a dose-dependently increased [125I]-hNPW23 dissociation rate constants from NPBWR1 in kinetic binding studies. Collectively, these data are inconsistent with a classic surmountable, orthosteric mechanism of inhibition. The benzimidazole inhibitors reported herein may therefore represent a mechanistically differentiated class of compounds with which to form a better appreciation of the pharmacology and physiological roles of this central neuropeptide system.


Assuntos
Benzimidazóis/farmacologia , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Receptores de Neuropeptídeos/antagonistas & inibidores , Animais , Benzimidazóis/síntese química , Células CHO , Cricetulus , Descoberta de Drogas , Humanos , Estrutura Molecular , Relação Estrutura-Atividade
7.
BJU Int ; 124(4): 609-620, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31106513

RESUMO

OBJECTIVES: To develop a risk classifier using urine-derived extracellular vesicle (EV)-RNA capable of providing diagnostic information on disease status prior to biopsy, and prognostic information for men on active surveillance (AS). PATIENTS AND METHODS: Post-digital rectal examination urine-derived EV-RNA expression profiles (n = 535, multiple centres) were interrogated with a curated NanoString panel. A LASSO-based continuation ratio model was built to generate four prostate urine risk (PUR) signatures for predicting the probability of normal tissue (PUR-1), D'Amico low-risk (PUR-2), intermediate-risk (PUR-3), and high-risk (PUR-4) prostate cancer. This model was applied to a test cohort (n = 177) for diagnostic evaluation, and to an AS sub-cohort (n = 87) for prognostic evaluation. RESULTS: Each PUR signature was significantly associated with its corresponding clinical category (P < 0.001). PUR-4 status predicted the presence of clinically significant intermediate- or high-risk disease (area under the curve = 0.77, 95% confidence interval [CI] 0.70-0.84). Application of PUR provided a net benefit over current clinical practice. In an AS sub-cohort (n = 87), groups defined by PUR status and proportion of PUR-4 had a significant association with time to progression (interquartile range hazard ratio [HR] 2.86, 95% CI 1.83-4.47; P < 0.001). PUR-4, when used continuously, dichotomized patient groups with differential progression rates of 10% and 60% 5 years after urine collection (HR 8.23, 95% CI 3.26-20.81; P < 0.001). CONCLUSION: Urine-derived EV-RNA can provide diagnostic information on aggressive prostate cancer prior to biopsy, and prognostic information for men on AS. PUR represents a new and versatile biomarker that could result in substantial alterations to current treatment of patients with prostate cancer.

8.
Prostate ; 78(15): 1134-1139, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29987889

RESUMO

BACKGROUND: We observed in cystoprostatectomy specimens that Bacillus Calmette-Guérin (BCG) granulomatous prostatitis tended preferentially to affect the peripheral zone (PZ) and aimed to study the matter, postulating that assessment of its distribution might contribute to understanding pathogenetic processes. METHODS: Entire prostate glands from 27 men (47-83 years; mean = 69 years), who had previously received intravesical BCG therapy for non-muscle-invasive urothelial carcinoma of the bladder, were studied as whole-mount sections to determine the anatomical distribution and histopathological characteristics of BCG prostatitis. RESULTS: Twenty-two (81.5%) showed BCG-type granulomatous inflammation. It often radiated from close to the prostatic urethra toward to the gland periphery as a wedge-shaped area related to one or more duct systems. Twenty-one of these prostate glands (95.5%) showed predominantly or exclusively PZ involvement. Eighteen (81.8%) involved only the PZ, while three cases (13.6%) also showed involvement of the transitional zone (TZ). One case (4.5%) involved only the TZ. No granulomas were seen in the central zone or anterior fibromuscular septum. CONCLUSIONS: Our observations imply the microanatomical arrangement of prostatic ducts is a factor in the pathogenesis of BCG prostatitis. PZ ducts enter the urethra at less obtuse angles than those from other zones and are likely to be more prone to urine reflux and damage from suspended BCG. We speculate that prostatic duct microanatomy could also play a role in the pathogenesis of other prostatic diseases, including conventional prostatitis and adenocarcinoma.


Assuntos
Vacina BCG/efeitos adversos , Prostatite/induzido quimicamente , Adenocarcinoma/induzido quimicamente , Adenocarcinoma/patologia , Idoso , Idoso de 80 Anos ou mais , Vacina BCG/administração & dosagem , Granuloma/induzido quimicamente , Granuloma/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Prostatite/patologia , Estudos Retrospectivos
9.
Bioorg Med Chem Lett ; 25(17): 3520-5, 2015 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-26199120

RESUMO

We report SAR studies on a novel non-peptidic somatostatin receptor 3 (SSTR3) agonist lead series derived from (4-phenyl-1H-imidazol-2-yl)methanamine. This effort led to the discovery of a highly potent low molecular weight SSTR3 agonist 5c (EC50=5.2 nM, MW=359). The results from molecular overlays of 5c onto the L-129 structure indicate good alignment, and two main differences of the proposed overlays of the antagonist MK-4256 onto the conformation of 5c lead to inversion of antagonism to agonism.


Assuntos
Metilaminas/química , Receptores de Somatostatina/química , Descoberta de Drogas , Humanos , Relação Estrutura-Atividade
10.
Bioorg Med Chem Lett ; 25(17): 3495-500, 2015 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-26142947

RESUMO

The triazolyl amide γ-secretase modulators are potent alternatives to the cinnamyl amides that have entered the clinic for the treatment of Alzheimer's disease. Herein we build on the lead benzoazepinones described in our prior communication with imidazomethoxyarene moiety alternatives that offer opportunities to fine tune physical properties as well as address hERG binding and PK. Both half-life and bioavailability were significantly improved, especially in dog, with robust brain Aß42 lowering maintained in both transgenic mouse and rat.


Assuntos
Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/farmacocinética , Animais , Disponibilidade Biológica , Camundongos , Camundongos Transgênicos , Ratos
11.
Anal Chem ; 86(12): 5758-65, 2014 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-24820266

RESUMO

In this study we report the exceptional potentiometric properties of pH microprobes made with nanostructured palladium hydride microelectrodes and demonstrate their application by monitoring pH variations resulting from a reaction confined in a porous medium. Their potentiometric response was found to be reproducible and stable over several hours but primarily Nernstian over a remarkably wide pH range, including alkaline conditions up to pH 14. Continuous operation was demonstrated by reloading hydrogen at regular intervals to maintain the correct hydride composition thereby alleviating the need for calibration. These properties were validated by detecting pH transients during the carbonation of Ca(OH)2 within a fibrous mesh. Experimental pHs recorded in situ were in excellent agreement with theoretical calculations for the CO2 partial pressures considered. Results also showed that the electrodes were sufficiently sensitive to differentiate between the formation of vaterite and calcite, two polymorphs of CaCO3. These nanostructured microelectrodes are uniquely suited to the determination of pH in highly alkaline solutions, particularly those arising from interfacial reactions at solid and porous surfaces and are thus highly appropriate as pH sensing tips in scanning electrochemical microscopy.

12.
J Comput Aided Mol Des ; 28(1): 5-12, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24488306

RESUMO

Dual Orexin Receptor Antagonists (DORA) bind to both the Orexin 1 and 2 receptors. High resolution crystal structures of the Orexin 1 and 2 receptors, both class A GPCRs, were not available at the time of this study, and thus, ligand-based analyses were invoked and successfully applied to the design of DORAs. Computational analysis, ligand based superposition, unbound small-molecule X-ray crystal structures and NMR analysis were utilized to understand the conformational preferences of key DORAs and excellent agreement between these orthogonal approaches was seen in the majority of compounds examined. The predominantly face-to-face (F2F) interaction observed between the distal aromatic rings was the core 3D shape motif in our design principle and was used in the development of compounds. A notable exception, however, was seen between computation and experiment for suvorexant where the molecule exhibits an extended conformation in the unbound small-molecule X-ray structure. Even taking into account solvation effects explicitly in our calculations, we nevertheless find support that the F2F conformation is the bioactive conformation. Using a dominant states approximation for the partition function, we made a comprehensive assessment of the free energies required to adopt both an extended and a F2F conformation of a number of DORAs. Interestingly, we find that only a F2F conformation is consistent with the activities reported.


Assuntos
Azepinas/química , Cristalografia por Raios X , Receptores de Orexina/química , Triazóis/química , Humanos , Ligantes , Espectroscopia de Ressonância Magnética , Conformação Molecular , Estrutura Molecular , Antagonistas dos Receptores de Orexina
13.
Nat Commun ; 15(1): 9247, 2024 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-39461959

RESUMO

Testicular germ cell tumours (TGCT), which comprise seminoma and non-seminoma subtypes, are the most common cancers in young men. In this study, we present a comprehensive whole genome sequencing analysis of adult TGCTs. Leveraging samples from participants recruited via the UK National Health Service and data from the Genomics England 100,000 Genomes Project, our results provide an extended description of genomic elements underlying TGCT pathogenesis. This catalogue offers a comprehensive, high-resolution map of copy number alterations, structural variation, and key global genome features, including mutational signatures and analysis of extrachromosomal DNA amplification. This study establishes correlations between genomic alterations and histological diversification, revealing divergent evolutionary trajectories among TGCT subtypes. By reconstructing the chronological order of driver events, we identify a subgroup of adult TGCTs undergoing relatively late whole genome duplication. Additionally, we present evidence that human leukocyte antigen loss is a more prevalent mechanism of immune disruption in seminomas. Collectively, our findings provide valuable insights into the developmental and immune modulatory processes implicated in TGCT pathogenesis and progression.


Assuntos
Variações do Número de Cópias de DNA , Neoplasias Embrionárias de Células Germinativas , Neoplasias Testiculares , Humanos , Neoplasias Testiculares/genética , Neoplasias Testiculares/patologia , Masculino , Neoplasias Embrionárias de Células Germinativas/genética , Neoplasias Embrionárias de Células Germinativas/patologia , Adulto , Variações do Número de Cópias de DNA/genética , Seminoma/genética , Seminoma/patologia , Genômica/métodos , Sequenciamento Completo do Genoma , Genoma Humano , Mutação
14.
Anal Chem ; 85(17): 8341-6, 2013 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-23919805

RESUMO

This study demonstrates how the potentiometric mode of the scanning electrochemical microscope (SECM) can be used to sensitively probe and alter the mixed potential due to two independent redox processes provided that the transport of one of the species involved is controlled by diffusion. This is illustrated with the discharge of hydrogen from nanostructured Pd hydride films deposited on the SECM tip. In deareated buffered solutions the open circuit potential of the PdH in equilibrium between its ß and α phases (OCP(ß→α)) does not depend on the tip-substrate distance while in aerated conditions it is found to be controlled by hindered diffusion of oxygen. Chronopotentiometric and amperometric measurements at several tip-substrate distances reveal how the flux of oxygen toward the Pd hydride film determines its potential. Linear sweep voltammetry shows that the polarization resistance increases when the tip approaches an inert substrate. The SECM methodology also demonstrates how dissolved oxygen affects the rate of hydrogen extraction from the Pd lattice. Over a wide potential window, the highly reactive nanostructure promotes the reduction of oxygen which rapidly discharges hydrogen from the PdH. The flux of oxygen toward the tip can be adjusted via hindered diffusion. Approaching the substrate decreases the flux of oxygen, lengthens the hydrogen discharge, and shifts OCP(ß→α) negatively. The results are consistent with a mixed potential due to the rate of oxygen reduction balancing that of the hydride oxidation. The methodology is generic and applicable to other mixed potential processes in corrosion or catalysis.

15.
J Org Chem ; 78(2): 706-10, 2013 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-23215022

RESUMO

The stereoselective addition of 2-phenyloxazol-4-yl trifluoromethanesulfonate to N-sulfinylimines is described. Vinyl anions derived from enol triflate 2 undergo 1,2-addition with a variety of aldimines to afford the corresponding secondary sulfonamides as single diastereomers. The absolute stereochemistry was confirmed by X-ray crystallography which provides support that the reaction proceeds through an open, nonchelate transition state. This methodology has been applied to the synthesis of the ketoamide fragment of the protease inhibitor boceprevir.


Assuntos
Hepacivirus/química , Hepacivirus/efeitos dos fármacos , Iminas/química , Mesilatos/química , Oxazóis/química , Prolina/análogos & derivados , Inibidores de Proteases/química , Inibidores de Proteases/síntese química , Cristalografia por Raios X , Estrutura Molecular , Prolina/síntese química , Prolina/química , Estereoisomerismo
16.
J Pathol ; 228(3): 405-15, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22864938

RESUMO

The tumour suppressor APC is the most commonly altered gene in colorectal cancer (CRC). Genetic and epigenetic alterations of APC may therefore be associated with dietary and lifestyle risk factors for CRC. Analysis of APC mutations in the extended mutation cluster region (codons 1276-1556) and APC promoter 1A methylation was performed on 185 archival CRC samples collected from participants of the European Prospective Investigation into Cancer (EPIC)-Norfolk study, with the aim of relating these to high-quality seven-day dietary and lifestyle data collected prospectively. Truncating APC mutations (APC(+) ) and promoter 1A methylation (PM(+) ) were identified in 43% and 23% of CRCs analysed, respectively. Distal CRCs were more likely than proximal CRCs to be APC(+) or PM(+) (p = 0.04). APC(+) CRCs were more likely to be moderately/well differentiated and microsatellite stable than APC(-) CRCs (p = 0.05 and 0.03). APC(+) CRC cases consumed more alcohol than their counterparts (p = 0.01) and PM(+) CRC cases consumed lower levels of folate and fibre (p = 0.01 and 0.004). APC(+) or PM(+) CRC cases consumed higher levels of processed meat and iron from red meat and red meat products (p = 0.007 and 0.006). Specifically, CRC cases harbouring GC-to-AT transition mutations consumed higher levels of processed meat (35 versus 24 g/day, p = 0.04) and iron from red meat and red meat products (0.8 versus 0.6 mg/day, p = 0.05). In a logistic regression model adjusted for age, sex and cigarette-smoking status, each 19 g/day (1SD) increment increase in processed meat consumption was associated with cases with GC-to-AT mutations (OR 1.68, 95% CI 1.03-2.75). In conclusion, APC(+) and PM(+) CRCs may be influenced by diet and GC-to-AT mutations in APC are associated with processed meat consumption, suggesting a mechanistic link with dietary alkylating agents, such as N-nitroso compounds.


Assuntos
Proteína da Polipose Adenomatosa do Colo/genética , Neoplasias Colorretais/genética , Neoplasias Colorretais/fisiopatologia , Dieta , Estilo de Vida , Mutação/genética , Regiões Promotoras Genéticas/fisiologia , Idoso , Consumo de Bebidas Alcoólicas/efeitos adversos , Registros de Dieta , Europa (Continente) , Feminino , Humanos , Modelos Logísticos , Masculino , Carne/efeitos adversos , Metilação , Instabilidade de Microssatélites , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos , Fumar/efeitos adversos
17.
Chem Commun (Camb) ; 59(48): 7423-7426, 2023 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-37249207

RESUMO

A blue light mediated photochemical process using solid graphitic carbon nitride (g-C3N4) in ambient air/isopropanol vapour is suggested to be linked to "nanophase" water inclusions and is shown to produce approx. 50 µmol H2O2 per gram of g-C3N4, which can be stored in the solid g-C3N4 for later release for applications, for example, in disinfection or anti-bacterial surfaces.

18.
J Org Chem ; 77(7): 3297-310, 2012 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-22423625

RESUMO

An efficient, new, and scalable semisynthesis of glucan synthase inhibitors 1 and 2 from the fermentation product enfumafungin 3 is described. The highlights of the synthesis include a high-yielding ether bond-forming reaction between a bulky sulfamidate 17 and alcohol 4 and a remarkably chemoselective, improved palladium(II)-mediated Corey-Yu allylic oxidation at the highly congested C-12 position of the enfumafungin core. Multi-hundred gram quantities of the target drug candidates 1 and 2 were prepared, in 12 linear steps with 25% isolated yield and 13 linear steps with 22% isolated yield, respectively.


Assuntos
Álcoois/química , Antifúngicos/síntese química , Antifúngicos/farmacologia , Crisenos/química , Crisenos/síntese química , Equinocandinas/química , Glucosiltransferases/antagonistas & inibidores , Glicosídeos/química , Paládio/química , Triterpenos/química , Catálise , Estrutura Molecular , Estereoisomerismo
19.
Bioorg Med Chem Lett ; 22(2): 1014-8, 2012 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-22197390

RESUMO

The synthesis and evaluation of small molecule antagonists of the G protein-coupled receptor NPBWR1 (GPR7) are reported for the first time. [4-(5-Chloropyridin-2-yl)piperazin-1-yl][(1S,2S,4R)-4-{[(1R)-1-(4-methoxyphenyl)ethyl]amino}-2-(thiophen-3-yl)cyclohexyl]methanone (1) emerged as a hit from a high-throughput screen. Examination of substituents that focused on replacing the 5-chloropyridine and 4-methoxybenzylamino groups of 1 led to the identification of compounds that exhibited subnanomolar potencies as low as 660pM (9k) in the functional assay and 200pM in the binding assay (9i).


Assuntos
Benzilaminas/farmacologia , Piperazinas/farmacologia , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Receptores de Neuropeptídeos/antagonistas & inibidores , Animais , Benzilaminas/síntese química , Benzilaminas/química , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Humanos , Camundongos , Modelos Moleculares , Estrutura Molecular , Piperazina , Piperazinas/síntese química , Piperazinas/química , Estereoisomerismo , Relação Estrutura-Atividade
20.
Bioorg Med Chem Lett ; 22(9): 3203-7, 2012 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-22483609

RESUMO

Alzheimer's disease is a major unmet medical need with pathology characterized by extracellular proteinaceous plaques comprised primarily of ß-amyloid. γ-Secretase is a critical enzyme in the cellular pathway responsible for the formation of a range of ß-amyloid peptides; one of which, Aß42, is believed to be responsible for the neuropathological features of the disease. Herein, we report 4,4 disubstituted piperidine γ-secretase inhibitors that were optimized for in vitro cellular potency and pharmacokinetic properties in vivo. Key agents were further characterized for their ability to lower cerebral Aß42 production in an APP-YAC mouse model. This structural series generally suffered from sub-optimal pharmacokinetics but hypothesis driven lead optimization enabled the discovery of γ-secretase inhibitors capable of lowering cerebral Aß42 production in mice.


Assuntos
Amidas/síntese química , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Inibidores Enzimáticos/química , Piperidinas/química , Doença de Alzheimer/tratamento farmacológico , Amidas/farmacologia , Peptídeos beta-Amiloides/biossíntese , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Camundongos , Fragmentos de Peptídeos/biossíntese
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