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Arnau Del Valle C, Thomas P, Galindo F, Muñoz MP, Marín MJ. Gold nanoparticle-based two-photon fluorescent nanoprobe for monitoring intracellular nitric oxide levels. J Mater Chem B 2023; 11:3387-3396. [PMID: 36919860 DOI: 10.1039/d3tb00103b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
Nitric oxide (NO) plays an important role in the regulation of the immune, cardiovascular and nervous systems. Consequently, being able to monitor and quantify intracellular NO levels would provide a greater understanding of the implications of this molecule in the different biological processes, including, for example, in cancer. Here, we report a broadly applicable two-photon excitable fluorescent nanoprobe able to detect and potentially quantify NO levels in an extensive range of cellular environments. The nanoprobe consists of a thiolated photoinduced electron transfer-based two=photon fluorescent probe attached onto the surface of 2.4 ± 0.7 nm gold nanoparticles (DANPY-NO@AuNPs). The nanoprobe, which can be synthesised in a reproducible manner and exhibits great stability when stored at room temperature, is able to selectively detect NO in solution, with a dynamic range up to 150 μM, and at pH values of biological relevance. DANPY-NO@AuNPs were able to selectively detect endogenous NO in RAW264.7γ NO- macrophages and THP-1 human leukemic cells; and endogenous and exogenous NO in endothelial cells. The nanoprobe accumulated in the acidic organelles of the tested cell lines showing negligible toxicity. Importantly, DANPY-NO@AuNPs showed potential to quantify intracellular NO concentrations in MDA-MB-231 breast cancer cells. The biological evaluation of the nanoprobe was undertaken using confocal laser scanning (images and intracellular emission spectra) and multiphoton microscopies, and flow cytometry. Based on their excellent sensitivity and stability, and outstanding versatility, DANPY-NO@AuNPs can be applied for the spatiotemporal monitoring of in vitro and in vivo NO levels.
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Affiliation(s)
- Carla Arnau Del Valle
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
| | - Paul Thomas
- Henry Wellcome Laboratory for Cell Imaging, Faculty of Science, University of East Anglia, Norwich Research Park, Norwich, NR4 7T, UK
| | - Francisco Galindo
- Departamento de Química Inorgánica y Orgánica, Universitat Jaume I, Av. Sos Baynat s/n, Castellón de la Plana, 12071, Spain
| | - María Paz Muñoz
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK. .,Department of Chemistry, Lancaster University, Bailrigg, Lancaster, LA1 4YB, UK
| | - María J Marín
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
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2
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Frei A, Elliott AG, Kan A, Dinh H, Bräse S, Bruce AE, Bruce MR, Chen F, Humaidy D, Jung N, King AP, Lye PG, Maliszewska HK, Mansour AM, Matiadis D, Muñoz MP, Pai TY, Pokhrel S, Sadler PJ, Sagnou M, Taylor M, Wilson JJ, Woods D, Zuegg J, Meyer W, Cain AK, Cooper MA, Blaskovich MAT. Metal Complexes as Antifungals? From a Crowd-Sourced Compound Library to the First In Vivo Experiments. JACS Au 2022; 2:2277-2294. [PMID: 36311838 PMCID: PMC9597602 DOI: 10.1021/jacsau.2c00308] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 07/01/2022] [Accepted: 07/27/2022] [Indexed: 06/16/2023]
Abstract
There are currently fewer than 10 antifungal drugs in clinical development, but new fungal strains that are resistant to most current antifungals are spreading rapidly across the world. To prevent a second resistance crisis, new classes of antifungal drugs are urgently needed. Metal complexes have proven to be promising candidates for novel antibiotics, but so far, few compounds have been explored for their potential application as antifungal agents. In this work, we report the evaluation of 1039 metal-containing compounds that were screened by the Community for Open Antimicrobial Drug Discovery (CO-ADD). We show that 20.9% of all metal compounds tested have antimicrobial activity against two representative Candida and Cryptococcus strains compared with only 1.1% of the >300,000 purely organic molecules tested through CO-ADD. We identified 90 metal compounds (8.7%) that show antifungal activity while not displaying any cytotoxicity against mammalian cell lines or hemolytic properties at similar concentrations. The structures of 21 metal complexes that display high antifungal activity (MIC ≤1.25 μM) are discussed and evaluated further against a broad panel of yeasts. Most of these have not been previously tested for antifungal activity. Eleven of these metal complexes were tested for toxicity in the Galleria mellonella moth larva model, revealing that only one compound showed signs of toxicity at the highest injected concentration. Lastly, we demonstrated that the organo-Pt(II) cyclooctadiene complex Pt1 significantly reduces fungal load in an in vivo G. mellonella infection model. These findings showcase that the structural and chemical diversity of metal-based compounds can be an invaluable tool in the development of new drugs against infectious diseases.
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Affiliation(s)
- Angelo Frei
- Centre
for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland4072, Australia
- Department
of Chemistry, Biochemistry & Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012Bern, Switzerland
| | - Alysha G. Elliott
- Centre
for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland4072, Australia
| | - Alex Kan
- Molecular
Mycology Research Laboratory, Centre for Infectious Diseases and Microbiology,
Faculty of Medicine and Health, Sydney Medical School, Westmead Clinical
School, Sydney Institute for Infectious Diseases, Westmead Hospital-Research
and Education Network, Westmead Institute for Medical Research, University of Sydney, Sydney, NSW2145, Australia
| | - Hue Dinh
- School
of Natural Sciences, ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, NSW2109, Australia
| | - Stefan Bräse
- Institute
of Organic Chemistry, Karlsruhe Institute
of Technology, Fritz-Haber-Weg 6, 76131Karlsruhe, Germany
- Institute
of Biological and Chemical Systems - Functional Molecular Systems, Karlsruhe Institute of Technology, 76344Eggenstein-Leopoldshafen, Germany
| | - Alice E. Bruce
- Department
of Chemistry, University of Maine, Orono, Maine04469, United States
| | - Mitchell R. Bruce
- Department
of Chemistry, University of Maine, Orono, Maine04469, United States
| | - Feng Chen
- Department
of Chemistry, University of Warwick, Gibbet Hill Road, CoventryCV4 7AL, U.K.
| | - Dhirgam Humaidy
- Department
of Chemistry, University of Maine, Orono, Maine04469, United States
| | - Nicole Jung
- Karlsruhe
Nano Micro Facility (KNMF), Karlsruhe Institute
of Technology, Hermann-von-Helmholtz-Platz 1, 76344Eggenstein-Leopoldshafen, Germany
- Institute
of Biological and Chemical Systems - Functional Molecular Systems, Karlsruhe Institute of Technology, 76344Eggenstein-Leopoldshafen, Germany
| | - A. Paden King
- Department
of Chemistry and Chemical Biology, Cornell
University, Ithaca, New York14853, United States
| | - Peter G. Lye
- School
of Science and Technology, University of
New England, Armidale, NSW2351, Australia
| | - Hanna K. Maliszewska
- School
of Chemistry, University of East Anglia, Norwich Research Park, NorwichNR4 7TJ, U.K.
| | - Ahmed M. Mansour
- Chemistry
Department, Faculty of Science, Cairo University, Giza12613, Egypt
| | - Dimitris Matiadis
- Institute
of Biosciences & Applications, National
Centre for Scientific Research “Demokritos”, 15310Athens, Greece
| | - María Paz Muñoz
- School
of Chemistry, University of East Anglia, Norwich Research Park, NorwichNR4 7TJ, U.K.
| | - Tsung-Yu Pai
- Molecular
Mycology Research Laboratory, Centre for Infectious Diseases and Microbiology,
Faculty of Medicine and Health, Sydney Medical School, Westmead Clinical
School, Sydney Institute for Infectious Diseases, Westmead Hospital-Research
and Education Network, Westmead Institute for Medical Research, University of Sydney, Sydney, NSW2145, Australia
| | - Shyam Pokhrel
- Department
of Chemistry, University of Maine, Orono, Maine04469, United States
| | - Peter J. Sadler
- Department
of Chemistry, University of Warwick, Gibbet Hill Road, CoventryCV4 7AL, U.K.
| | - Marina Sagnou
- Institute
of Biosciences & Applications, National
Centre for Scientific Research “Demokritos”, 15310Athens, Greece
| | - Michelle Taylor
- School
of Science and Technology, University of
New England, Armidale, NSW2351, Australia
| | - Justin J. Wilson
- Department
of Chemistry and Chemical Biology, Cornell
University, Ithaca, New York14853, United States
| | - Dean Woods
- School
of Science and Technology, University of
New England, Armidale, NSW2351, Australia
| | - Johannes Zuegg
- Centre
for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland4072, Australia
| | - Wieland Meyer
- Molecular
Mycology Research Laboratory, Centre for Infectious Diseases and Microbiology,
Faculty of Medicine and Health, Sydney Medical School, Westmead Clinical
School, Sydney Institute for Infectious Diseases, Westmead Hospital-Research
and Education Network, Westmead Institute for Medical Research, University of Sydney, Sydney, NSW2145, Australia
| | - Amy K. Cain
- School
of Natural Sciences, ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, NSW2109, Australia
| | - Matthew A. Cooper
- Centre
for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland4072, Australia
| | - Mark A. T. Blaskovich
- Centre
for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland4072, Australia
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Arnau Del Valle C, Williams L, Thomas P, Johnson R, Raveenthiraraj S, Warren D, Sobolewski A, Muñoz MP, Galindo F, Marín MJ. A highly photostable and versatile two-photon fluorescent probe for the detection of a wide range of intracellular nitric oxide concentrations in macrophages and endothelial cells. J Photochem Photobiol B 2022; 234:112512. [PMID: 35850002 DOI: 10.1016/j.jphotobiol.2022.112512] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 06/20/2022] [Accepted: 07/02/2022] [Indexed: 06/15/2023]
Abstract
Nitric oxide (NO) is involved in many biological processes affecting the cardiovascular, nervous and immune systems. Intracellular NO can be monitored using fluorescent probes in combination with fluorescence imaging techniques. Most of the currently available NO fluorescent molecular probes are excited via one-photon excitation using UV or Vis light, which results in poor penetration and high photodamage to living tissues. Here, we report a two-photon fluorescent molecular probe, DANPY-NO, able to detect NO in live cells. The probe consists of an o-phenylenediamine linked to a naphthalimide core; and operates via photoinduced electron transfer. DANPY-NO exhibits good sensitivity (LOD of 77.8 nM) and high selectivity towards NO, and is stable over a broad range of pHs. The probe targeted acidic organelles within macrophages and endothelial cells, and demonstrated enhanced photostability over a commercially available NO probe. DANPY-NO was used to selectively detect endogenous NO in RAW264.7ϒ NO- macrophages, THP-1 human leukemic cells, primary mouse (bone marrow-derived) macrophages and endothelial cells. The probe was also able to detect exogenous NO in endothelial cells and distinguish between increasing concentrations of NO. The NO detection was evidenced using confocal laser scanning and two-photon microscopies, and flow cytometry. Further evidence was obtained by recording the changes in the intracellular fluorescence emission spectrum of the probe. Importantly, the probe displayed negligible toxicity to the analysed biological samples. The excellent sensitivity, selectivity, stability and versatility of DANPY-NO confirm its potential for in vitro and in vivo imaging of NO.
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Affiliation(s)
- Carla Arnau Del Valle
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Lewis Williams
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Paul Thomas
- Faculty of Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Robert Johnson
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | | | - Derek Warren
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Anastasia Sobolewski
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - María Paz Muñoz
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Francisco Galindo
- Departamento de Química Inorgánica y Orgánica, Universitat Jaume I, Av. Sos Baynat s/n, Castellón de la Plana 12071, Spain
| | - María J Marín
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
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Maliszewska HK, Arnau Del Valle C, Xia Y, Marín MJ, Waller ZAE, Muñoz MP. Precious metal complexes of bis(pyridyl)allenes: synthesis and catalytic and medicinal applications. Dalton Trans 2021; 50:16739-16750. [PMID: 34761768 DOI: 10.1039/d1dt02929k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The incorporation of donor-type substituents on the allene core opens up the possibility of coordination complexes in which the metal is bonded to the donor groups, with or without interaction with the double bond system. Despite the challenges in the synthesis of such allene-containing metal complexes, their unique 3D environments and dual functionality (allene and metal) could facilitate catalysis and interaction with chemical and biological systems. Bis(pyridyl)allenes are presented here as robust ligands for novel Pd(II), Pt(IV) and Au(III) complexes. Their synthesis, characterisation and first application as catalysts of benchmark reactions for Pd, Pt and Au are presented with interesting reactivity and selectivities. The complexes have also been probed as antimicrobial and anticancer agents with promising activities, and the first studies on their unusual interaction with several DNA structures will open new avenues for research in the area of metallodrugs with new mechanisms of action.
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Affiliation(s)
- Hanna K Maliszewska
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
| | - Carla Arnau Del Valle
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
| | - Ying Xia
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - María J Marín
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
| | - Zoë A E Waller
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.,UCL School of Pharmacy, 29-39 Brunswick Square, London, WC1N 1AX, UK
| | - María Paz Muñoz
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
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Díaz LA, López M, Sin P, Wolff R, González G, Muñoz MP, Uribe M, Ananias Á, Bezama I, Zañartu N, Buckel E, Innocenti F, Pattillo JC, Jarufe N, Martínez J, Guerra JF, Elgueta S, Gana JC. [Current situation of pediatric liver transplantation in Chile. Inequities associated with the MELD/PELD prioritization system]. Rev Med Chil 2021; 148:1261-1270. [PMID: 33399701 DOI: 10.4067/s0034-98872020000901261] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 09/14/2020] [Indexed: 11/17/2022]
Abstract
BACKGROUND The Chilean allocation system for liver transplantation (LT) uses the MELD/PELD score to prioritize candidates on the waiting list. AIM To assess if the Chilean allocation system for LT is equitable for pediatric candidates compared to their adult counterparts. MATERIAL AND METHODS We used the Public Health Institute's registry between October 2011 and December 2017. We analyzed candidates with chronic hepatic diseases listed for LT. The primary outcome was the cadaveric liver transplantation (CLT) rate. Secondary outcomes were death or disease progression in the waiting list and living donor liver transplant (LDLT) rate. RESULTS We analyzed 122 pediatric and 735 adult candidates. Forty one percent of pediatric candidates obtained a CLT compared to 48% of adults (p = NS). Among patients aged under two years of age, the access to CLT on the waiting list there was 28% of CLT, compared to 48% in adults (p = 0.001). Fifty-seven percent of candidates aged under two years were listed for cholestatic diseases, obtaining a CLT in 18% and requiring a LDLT in 49%. The median time in the waiting list for CLT was 5.9 months in pediatric candidates and 5.1 in adults, while the median time to death in the waiting list was 2.8 and 5.6 months, respectively. The mortality rate at one year in candidates under two years old was 38.1% compared to 32.5% in adults. CONCLUSIONS Pediatric candidates with chronic liver diseases, especially under two years of age, have greater access difficulties to CLT than adults. Half of the pediatric candidates die on the waiting list before three months. The mortality among candidates under two years of age in the waiting list is excessively high.
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Affiliation(s)
- Luis Antonio Díaz
- Departamento de Gastroenterología, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Marisol López
- Departamento de Pediatría, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Priscila Sin
- División de Pediatría, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Rodrigo Wolff
- Departamento de Gastroenterología, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | | | - Mario Uribe
- Hospital Dr. Luis Calvo Mackenna, Santiago, Chile
| | - Álvaro Ananias
- Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Ignacio Bezama
- Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Nicolás Zañartu
- Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | | | - Juan Carlos Pattillo
- División de Cirugía, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | - Jorge Martínez
- División de Cirugía, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Juan Francisco Guerra
- MedStar Georgetown Transplant Institute, Medstar Georgetown University Hospital, Washington D.C., Estados Unidos de Norteamérica
| | | | - Juan Cristóbal Gana
- División de Pediatría, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
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Affiliation(s)
- José M. Alonso
- Departamento de Química Orgánica Universidad Complutense de Madrid Avda. Complutense s/n 28040 Madrid Spain
| | - María Paz Muñoz
- School of Chemistry University of East Anglia Earlham Road 4 7TJ Norwich, NR UK
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7
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Villanueva M, Oyarzún A, Leyton B, González M, Navarro E, Canales P, Ossa C, Muñoz MP, Bascuñán KA, Araya M. Changes in Age at Diagnosis and Nutritional Course of Celiac Disease in the Last Two Decades. Nutrients 2020; 12:nu12010156. [PMID: 31935859 PMCID: PMC7019995 DOI: 10.3390/nu12010156] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 12/31/2019] [Accepted: 01/02/2020] [Indexed: 12/13/2022] Open
Abstract
The frequency of celiac disease (CD) has increased along time, with relevant changes reported in geographical variations, clinical presentation and nutritional repercussions. In recent years, some celiac patients are presenting overweight/obesity, but it is unclear how frequent this is and to what extent undernutrition remains a concern. This is relevant because CD tends to be overlooked in overweight patients. With this in mind, we assessed age at diagnosis, clinical characteristics and nutritional status of 155 celiac patients diagnosed between 1994–2017 in four pediatric hospitals in Santiago, Chile. Since 2003, the number of patients diagnosed has increased (p < 0.0033), coinciding with antitransglutaminase and antiendomysial antibodies becoming available to public health systems. In 2000, 4.5% of patients were asymptomatic at diagnosis, suggesting that active search is not routinely applied. Gastrointestinal symptoms plus failure to thrive were significantly more frequent under 2 years (p = 0.0001). Nutritional status has improved at diagnosis and during follow up, but undernutrition remains more frequent in children <2 and <5 years (p < 0.002 and p < 0.0036, respectively). Overweight at diagnosis was reported in 2002 and obesity in 2010. After initiating treatment, since 2010, patients changing from undernourishment to overweight has sometimes been observed after only 6 months on a gluten-free diet.
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Affiliation(s)
- Mónica Villanueva
- Fellow, Pediatric Gastroenterology and Nutrition Program, Faculty of Medicine, University of Chile, Santiago, Chile, Clínica Alemana de Santiago, Chile;
| | - Amaya Oyarzún
- Institute of Nutrition and Food Technology (INTA), University of Chile, Santiago, Chile; (A.O.); (B.L.); (K.A.B.)
| | - Bárbara Leyton
- Institute of Nutrition and Food Technology (INTA), University of Chile, Santiago, Chile; (A.O.); (B.L.); (K.A.B.)
| | | | | | - Paulina Canales
- Hospital Exequiel González Cortés, Santiago, Chile; (E.N.); (P.C.)
| | - Cristobal Ossa
- Hospital Luis Calvo Mackenna, Santiago, Chile; (C.O.); (M.P.M.)
| | - María Paz Muñoz
- Hospital Luis Calvo Mackenna, Santiago, Chile; (C.O.); (M.P.M.)
| | - Karla A. Bascuñán
- Institute of Nutrition and Food Technology (INTA), University of Chile, Santiago, Chile; (A.O.); (B.L.); (K.A.B.)
- Department of Nutrition, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Magdalena Araya
- Institute of Nutrition and Food Technology (INTA), University of Chile, Santiago, Chile; (A.O.); (B.L.); (K.A.B.)
- Correspondence:
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Abstract
We report here the synthesis, full characterisation and first application in catalysis of novel Au(i), Au(iii) and Pt(ii) carbene-type complexes formed from bis(pyridyl)allenes. The catalytic activity of the new Au(i)-complexes in the cyclisation of 1,6-enynes, a benchmark reaction for new Au and Pt complexes, was comparable to Au(i)-state-of-the-art catalysts used in these reactions. Reactions with the new Au(iii)- and Pt(ii)-complexes occurred under milder conditions than those reported with AuCl3 and PtCl2.
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Affiliation(s)
- Hanna K Maliszewska
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
| | - David L Hughes
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
| | - María Paz Muñoz
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
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Abstract
Abstract
The mechanism of the platinum-catalysed dihydroalkoxylation of allenes to give acetals has been studied experimentally and by computational methods. Our findings further explain divergent reactivity encountered for platinum- and gold-vinyl intermediates after the first nucleophilic attack onto the coordinated allene, as well as provide new details on the catalytic cycle with platinum, uncovering enol ethers as resting states of the catalytic cycle, a SEOx process via Pt(IV)–H as the final protodemetallation step after the second nucleophilic attack when neutral platinum complexes are used, and a fast acid promoted addition of methanol to enol ethers when cationic platinum complexes are employed.
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Affiliation(s)
- María Teresa Quirós
- School of Chemistry , University of East Anglia , Earlham Road , Norwich , NR4 7TJ , UK
| | - Enrique Gómez-Bengoa
- Departamento de Química Orgánica , Universidad del País Vasco , Apt. 1072 , 20080 San Sebastián , Spain
| | - María Paz Muñoz
- School of Chemistry , University of East Anglia , Earlham Road , Norwich , NR4 7TJ , UK
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10
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Affiliation(s)
- José Miguel Alonso
- School of Chemistry, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - María Paz Muñoz
- School of Chemistry, University of East Anglia, Norwich NR4 7TJ, United Kingdom
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11
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Muñoz MP, Vega Á, Lecaros D, Saitua F. [Description of capsule endoscopy use in a pediatric public hospital]. Rev Chil Pediatr 2018; 89:339-345. [PMID: 29999139 DOI: 10.4067/s0370-41062018005000102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 02/15/2018] [Indexed: 06/08/2023]
Abstract
INTRODUCTION Capsule endoscopy (CE) is a non-invasive technique that allows visualization of small intestine mucosa. It is used for diagnosis of lesions not accessible with other tests. Our goal was to describe the experience using CE in a pediatric public hospital in Chile. PATIENTS AND METHOD A retrospective study was carried out to review the cases in which CE was used at Dr. Luis Calvo Mac- kenna Hospital from 2010 to date. Demographic and clinical data, findings, complications, diagnosis and treatment were recorded. RESULTS Twenty procedures were performed in 16 patients, 11 men (69%), median age 12 years (range 3 to 15 years). Indications included polyposis study (60%), sus pected Crohn disease (20%), obscure gastrointestinal bleeding (15%) and undiagnosed anemia (5%). Seventeen studies were altered (85%) and 11 led to a diagnosis or clinical behavior change (55%). There were no complications. CONCLUSIONS CE is a useful and safe technique in children, feasible to perform in a pediatric public hospital.
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Affiliation(s)
- María Paz Muñoz
- Unidad de Gastroenterología, Hospital Dr. Luis Calvo Mackenna, Chile
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12
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Cooper L, Alonso JM, Eagling L, Newson H, Herath S, Thomson C, Lister A, Howsham C, Cox B, Muñoz MP. Synthesis of a Novel Type of 2,3'-BIMs via Platinum-Catalysed Reaction of Indolylallenes with Indoles. Chemistry 2018; 24:6105-6114. [PMID: 29393548 PMCID: PMC5947743 DOI: 10.1002/chem.201705417] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Indexed: 12/17/2022]
Abstract
Optimisation, scope and mechanism of the platinum-catalysed addition of indoles to indolylallenes is reported here to give 2,3'-BIMs with a novel core structure very relevant for pharmaceutical industry. The reaction is modulated by the electronic properties of the substituents on both indoles, with the 2,3'-BIMs favoured when electron donating groups are present. Although simple at first, a complex mechanism has been uncovered that explains the different behaviour of these systems with platinum when compared with other metals (e.g. gold). Detailed labelling studies have shown Pt-catalysed 6-endo-trig cyclisation of the indollylallene as the first step of the reaction and the involvement of two cyclic vinyl-platinum intermediates in equilibrium through a platinum carbene, as the key intermediates of the catalytic cycle towards the second nucleophilic attack and formation of the BIMs.
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Affiliation(s)
- Lisa Cooper
- School of ChemistryUniversity of East AngliaEarlham RoadNorwichNR4 7TJUK
| | - José Miguel Alonso
- School of ChemistryUniversity of East AngliaEarlham RoadNorwichNR4 7TJUK
| | - Louise Eagling
- School of ChemistryUniversity of East AngliaEarlham RoadNorwichNR4 7TJUK
- Novartis Pharmaceuticals (UK) LimitedRH12 5AB, HorshamWest SussexUK
| | - Helen Newson
- School of ChemistryUniversity of East AngliaEarlham RoadNorwichNR4 7TJUK
- Novartis Pharmaceuticals (UK) LimitedRH12 5AB, HorshamWest SussexUK
| | - Sachini Herath
- School of ChemistryUniversity of East AngliaEarlham RoadNorwichNR4 7TJUK
| | | | - Andrew Lister
- Novartis Pharmaceuticals (UK) LimitedRH12 5AB, HorshamWest SussexUK
| | | | - Brian Cox
- Novartis Pharmaceuticals (UK) LimitedRH12 5AB, HorshamWest SussexUK
| | - María Paz Muñoz
- School of ChemistryUniversity of East AngliaEarlham RoadNorwichNR4 7TJUK
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Cooper L, Alonso JM, Eagling L, Newson H, Herath S, Thomson C, Lister A, Howsham C, Cox B, Muñoz MP. Cover Feature: Synthesis of a Novel Type of 2,3′-BIMs via Platinum-Catalysed Reaction of Indolylallenes with Indoles (Chem. Eur. J. 23/2018). Chemistry 2018. [DOI: 10.1002/chem.201801038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Lisa Cooper
- School of Chemistry; University of East Anglia; Earlham Road Norwich NR4 7TJ UK
| | - José Miguel Alonso
- School of Chemistry; University of East Anglia; Earlham Road Norwich NR4 7TJ UK
| | - Louise Eagling
- School of Chemistry; University of East Anglia; Earlham Road Norwich NR4 7TJ UK
- Novartis Pharmaceuticals (UK) Limited; RH12 5AB, Horsham West Sussex UK
| | - Helen Newson
- School of Chemistry; University of East Anglia; Earlham Road Norwich NR4 7TJ UK
- Novartis Pharmaceuticals (UK) Limited; RH12 5AB, Horsham West Sussex UK
| | - Sachini Herath
- School of Chemistry; University of East Anglia; Earlham Road Norwich NR4 7TJ UK
| | | | - Andrew Lister
- Novartis Pharmaceuticals (UK) Limited; RH12 5AB, Horsham West Sussex UK
| | - Catherine Howsham
- Novartis Pharmaceuticals (UK) Limited; RH12 5AB, Horsham West Sussex UK
| | - Brian Cox
- Novartis Pharmaceuticals (UK) Limited; RH12 5AB, Horsham West Sussex UK
| | - María Paz Muñoz
- School of Chemistry; University of East Anglia; Earlham Road Norwich NR4 7TJ UK
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Alonso JM, Muñoz MP. Heterobimetallic Catalysis: Platinum-Gold-Catalyzed Tandem Cyclization/C-X Coupling Reaction of (Hetero)Arylallenes with Nucleophiles. Angew Chem Int Ed Engl 2018; 57:4742-4746. [PMID: 29493867 DOI: 10.1002/anie.201800670] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Indexed: 01/26/2023]
Abstract
Heterobimetallic catalysis offers new opportunities for reactivity and selectivity but still presents challenges, and only a few metal combinations have been explored so far. Reported here is a Pt-Au heterobimetallic catalyst system for the synthesis of a family of multi-heteroaromatic structures through tandem cyclization/C-X coupling reaction. Au-catalyzed 6-endo-cyclization takes place as the first fast step. Pt-Au clusters are proposed to be responsible for the increased reactivity in the second step, that is, the intermolecular nucleophilic addition which occurs through an outer-sphere mechanism by hybrid homogeneous-heterogeneous catalysis.
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Affiliation(s)
| | - María Paz Muñoz
- School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, UK
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Alonso JM, Muñoz MP. Heterobimetallic Catalysis: Platinum‐Gold‐Catalyzed Tandem Cyclization/C−X Coupling Reaction of (Hetero)Arylallenes with Nucleophiles. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201800670] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
| | - María Paz Muñoz
- School of Chemistry University of East Anglia Norwich NR4 7TJ UK
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16
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Valdés M, Hanchey A, Muñoz MP, Baumert B, Iglesias V. Low-level arsenic exposure during pregnancy and its association with postpartum depression: A cohort study of women from Arica, Chile. Rev Epidemiol Sante Publique 2017; 65:427-435. [PMID: 29110958 DOI: 10.1016/j.respe.2017.05.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 01/21/2017] [Accepted: 05/30/2017] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND While the relationship between inorganic arsenic exposure and psychological impairment has been studied previously, the association between low-level arsenic exposure during pregnancy and postpartum depression has not yet been examined. The objective is to estimate the association between low-level arsenic exposure during pregnancy and the Edinburgh score. METHODS A sample of 223 women was collected from five public health services in Arica, Chile. Participation was voluntary and written consent was mandatory. Sociodemographic data related to arsenic exposure and urine samples for total inorganic arsenic assessments were collected during the second trimester. Postpartum depression symptoms were estimated by the Edinburgh Postpartum Depression scale. We examined descriptive statistics and ran multiple linear regressions. The modifying effect of age and depression history was evaluated separately. RESULTS The median for total urinary inorganic arsenic was 14.6μg/L (range: 2-69.2μg/L), the median for postpartum depression score was 8 points (range: 0-27 points) and 20.6% of women were considered as postpartum depressed. For women older than 25years old without depression history, the adjusted coefficient for the total urinary natural logarithm of inorganic arsenic in multiple linear regressions was -2.51 (95% CI: -4.54, -0.48; P-value=0.02). For women older than 25years old with a depression history, this value was 2.09 (95% CI: -0.90, 5.08; P-value=0.16). CONCLUSIONS In this cohort, the number of children, physical perception, depression history, stressful maternity, and age were associated with postpartum depression score. The Edinburgh score was associated with inorganic arsenic in women older than 25years without depression history.
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Affiliation(s)
- M Valdés
- Becaria CONICYT, Programa Doctorado en Salud Pública, Escuela de Salud Pública, Facultad de Medicina, Universidad de Chile, Independencia 939, Santiago, Chile
| | - A Hanchey
- Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, 150, East Green Street, 30602 Athens, GA, USA
| | - M P Muñoz
- Escuela de Salud Pública, Facultad de Medicina, Universidad de Chile, Independencia 939, Santiago, Chile
| | - B Baumert
- Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, 150, East Green Street, 30602 Athens, GA, USA
| | - V Iglesias
- Escuela de Salud Pública, Facultad de Medicina, Universidad de Chile, Independencia 939, Santiago, Chile.
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Quirós MT, Hurtado-Rodrigo C, Muñoz MP. Nucleophile dependent formation of 6- and 7-membered N-heterocycles by platinum-catalysed cyclisation of 1,5-bisallenes. Org Biomol Chem 2017; 15:6731-6737. [PMID: 28782779 DOI: 10.1039/c7ob01469d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
An unprecedented Pt-catalysed cyclisation of N-tethered 1,5-bisallenes in the presence of oxygen nucleophiles is reported, where formation of 6- or 7-membered rings is driven by the choice of nucleophile and the mechanism dictated by the nucleophile and the electronic properties of the bisallene. The reaction in the presence of alcohols gives preferentially vinyltetrahydropyridines with an extra alkoxy group and Pt-H as the active species in the catalytic cycle, while formation of di- and tetrahydroazepines with an extra hydroxyl group is favoured when water is used as nucleophile, via nucleophilic attack/carbocyclization as the favoured pathway. The products obtained are frequently found in the core of natural products with important biological activities, so understanding this complex mechanistic behaviour and exploiting this new methodology will have a big impact in organic synthesis and organometallic chemistry.
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Quirós MT, Muñoz MP, Christensen J, Coles SJ. Twists and Turns of Platinum-Allene Complexes: NMR Techniques for the Study of the Dynamic Behavior in Solution. Organometallics 2016. [DOI: 10.1021/acs.organomet.6b00778] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- M. Teresa Quirós
- School of Chemistry, University of East Anglia, Earlham Road, NR4 7TJ, Norwich, U.K
| | - María Paz Muñoz
- School of Chemistry, University of East Anglia, Earlham Road, NR4 7TJ, Norwich, U.K
| | - Jeppe Christensen
- UK National Crystallography Service, Chemistry, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, U.K
- Diamond Light Source, Harwell Science and Innovation Campus, Oxfordshire OX11 0DE, U.K
| | - Simon J. Coles
- UK National Crystallography Service, Chemistry, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, U.K
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Quirós MT, Macdonald C, Angulo J, Muñoz MP. Spin Saturation Transfer Difference NMR (SSTD NMR): A New Tool to Obtain Kinetic Parameters of Chemical Exchange Processes. J Vis Exp 2016. [PMID: 27911361 PMCID: PMC5226224 DOI: 10.3791/54499] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
This detailed protocol describes the new Spin Saturation Transfer Difference Nuclear Magnetic Resonance protocol (SSTD NMR), recently developed in our group to study processes of mutual-site chemical exchange that are difficult to analyze by traditional methods. As the name suggests, this method combines the Spin Saturation Transfer method used for small molecules, with the Saturation Transfer Difference (STD) NMR method employed for the study of protein-ligand interactions, by measuring transient spin saturation transfer along increasing saturation times (build-up curves) in small organic and organometallic molecules undergoing chemical exchange. Advantages of this method over existing ones are: there is no need to reach coalescence of the exchanging signals; the method can be applied as long as one signal of the exchanging sites is isolated; there is no need to measure T1 or reach steady state saturation; rate constant values are measured directly, and T1 values are obtained in the same experiment, using only one set of experiments. To test the method, we have studied the dynamics of the hindered rotation of N,N-dimethylamides, for which much data is available for comparison. The thermodynamic parameters obtained using SSTD are very similar to the reported ones (spin-saturation transfer techniques and line-shape analysis). The method can be applied to more challenging substrates that cannot be studied by previous methods. We envisage that the simple experimental set up and the wide applicability of the method to a great variety of substrates will make this a common technique amongst organic and organometallic chemists without extensive expertise in NMR.
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Affiliation(s)
| | - Colin Macdonald
- School of Chemistry, University of East Anglia; School of Pharmacy, University of East Anglia;
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Mena MÁ, Perucho J, Gómez A, Muñoz MP, Yébene JGD, Casarejos MJ. L25 Trehalose rescues glial cell dysfunction in striatal cultures from HD R6/1 mice at early postnatal development. J Neurol Neurosurg Psychiatry 2016. [DOI: 10.1136/jnnp-2016-314597.280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Abstract
This review covers chirality transfer in metal-catalysed intermolecular addition reactions involving allenes, including axial-to-central chirality transfer, asymmetric catalysis and racemization.
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Quirós MT, Angulo J, Muñoz MP. Kinetics of intramolecular chemical exchange by initial growth rates of spin saturation transfer difference experiments (SSTD NMR). Chem Commun (Camb) 2015; 51:10222-5. [PMID: 26022614 DOI: 10.1039/c5cc02941d] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report here the Initial Growth Rates SSTD NMR method, as a new powerful tool to obtain the kinetic parameters of intramolecular chemical exchange in challenging small organic and organometallic molecules.
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Affiliation(s)
- M Teresa Quirós
- School of Chemistry, University of East Anglia, Earlham Road, NR4 7TJ, Norwich, UK.
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Affiliation(s)
- Carolina Valderas
- Departamento de Quı́mica Orgánica, Facultad de Quı́mica, Universidad Complutense, 28040-Madrid, Spain
- Instituto de Quı́mica
Orgánica General, Consejo Superior de Investigaciones Cientı́ficas (CSIC), Juan de la Cierva 3, 28006-Madrid, Spain
| | - María C. de la Torre
- Instituto de Quı́mica
Orgánica General, Consejo Superior de Investigaciones Cientı́ficas (CSIC), Juan de la Cierva 3, 28006-Madrid, Spain
| | - Israel Fernández
- Departamento de Quı́mica Orgánica, Facultad de Quı́mica, Universidad Complutense, 28040-Madrid, Spain
| | - María Paz Muñoz
- Instituto de Quı́mica
Orgánica General, Consejo Superior de Investigaciones Cientı́ficas (CSIC), Juan de la Cierva 3, 28006-Madrid, Spain
| | - Miguel A. Sierra
- Departamento de Quı́mica Orgánica, Facultad de Quı́mica, Universidad Complutense, 28040-Madrid, Spain
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Abstract
Transition metal catalysed hydroalkoxylation of allenes has received much attention in recent years, and both the intra- and intermolecular versions have been reported. Gold(I) complexes are among the most active catalysts for these processes. This critical perspective article will cover the progress in this field, analysing the intermolecular metal-catalysed reaction of allenes using palladium, iridium, rhodium, ruthenium, gold and platinum, in the presence of alcohols, water or carboxylic acids, and the mechanistic implications of these processes depending on the metal used.
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Affiliation(s)
- María Paz Muñoz
- School of Chemistry, University of East Anglia, Norwich, UK.
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27
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Muñoz MP, de la Torre MC, Sierra MA. Platinum-Catalysed Bisindolylation of Allenes: A Complementary Alternative to Gold Catalysis. Chemistry 2012; 18:4499-504. [DOI: 10.1002/chem.201103337] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Indexed: 11/10/2022]
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Villas F, Compes E, Fernández-Nieto M, Muñoz MP, Bartolome B, de las Heras M. Bird-egg syndrome caused by Agapornis species (lovebird). J Investig Allergol Clin Immunol 2009; 19:71-72. [PMID: 19274938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Affiliation(s)
- F Villas
- Allergy Department, Hospital Obispo Polanco, Teruel, Spain.
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Abstract
Varicella is a disease caused by varicella-zoster virus. It is transmitted via the respiratory route, is highly communicable and mainly affects young children. An effective vaccine is now available, whose routine use is advised by health authorities in the USA and which can prevent severe disease, although breakthrough infections do occur. In deciding whether or not to include a vaccine in the routine vaccination schedule, knowledge of the morbidity of the disease in question is fundamental. Although reporting of varicella is compulsory in Catalonia, doctors only have to report the weekly number of cases diagnosed, and not their age distribution. Given that recent data on the prevalence of the infection in Catalonia according to age groups is available, it was considered that, using these data, an estimation of age-related incidence could be made. The objective of the present study was to estimate the incidence of varicella in Catalonia on the basis of the available seroprevalence data. A curve was fitted to the observed prevalence and point prevalence estimates for all ages were obtained. The incidence was derived by smoothed prevalence for each of these age groups. Estimated variance of the estimated incidence was obtained by the delta method. Predicted prevalence in the 0-4 years age group was calculated by the smoothed prevalence. The model that best fitted the sample prevalence was the exponential function. The estimated number of varicella cases in this study was 46,419 (95% CI 40,507-52,270). As the population in Catalonia in 1996 was 6,090,040, the previous results give an incidence rate of 762.2 per 100,000 persons/year with their 95% CI (666.1-858.3). The method described may be applied to the study of incidence rates in relation to the prevalence of diseases if we accept that the infection produces permanent immunity; the risk of mortality is the same for infected and non-infected subjects and that the disease incidence and population remain constant in time.
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Affiliation(s)
- M P Muñoz
- Department of Statistics and Operational Research, Universitat Politècnica de Catalunya, Barcelona, Spain
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Méndez M, Muñoz MP, Nevado C, Cárdenas DJ, Echavarren AM. Cyclizations of enynes catalyzed by PtCl2 or other transition metal chlorides: divergent reaction pathways. J Am Chem Soc 2001; 123:10511-20. [PMID: 11673982 DOI: 10.1021/ja0112184] [Citation(s) in RCA: 279] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
1-en-6-ynes react with alcohols or water in the presence of PtCl2 as catalyst to give carbocycles with alkoxy or hydroxy functional groups at the side chain. The reaction proceeds by anti attack of the alkene onto the (eta2-alkyne)platinum complex. The formation of the C-C and C-O bonds takes place stereoselectively by trans addition of the electrophile derived from the alkyne and the nucleophile to the double bond of the enyne. Formation of five- or six-membered carbo- or heterocycles could be obtained from 1-en-6-ynes depending on the substituents on the alkene or at the tether. Although more limited in scope, Ru(II) and Au(III) chlorides also give rise to alkoxy- or hydroxycyclization of enynes. On the basis of density functional theory (DFT) calculations, a cyclopropyl platinacarbene complex was found as the key intermediate in the process. In the presence of polar, nonnucleophilic solvents, 1-en-6-ynes are cycloisomerized with PtCl2 as catalyst. Formation of a platinacyclopentene intermediate is supported by DFT calculations. The reaction takes place by selective hydrogen abstraction of the trans-allylic substituent. Cycloisomerization of enynes containing disubstituted alkenes could be carried out using RuCl3 or Ru(AsPh3)4Cl2 in MeOH.
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Affiliation(s)
- M Méndez
- Departamento de Química Orgánica, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
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Vargas SL, Ponce CA, Gigliotti F, Ulloa AV, Prieto S, Muñoz MP, Hughes WT. Transmission of Pneumocystis carinii DNA from a patient with P. carinii pneumonia to immunocompetent contact health care workers. J Clin Microbiol 2000; 38:1536-8. [PMID: 10747139 PMCID: PMC86483 DOI: 10.1128/jcm.38.4.1536-1538.2000] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The transmission of Pneumocystis carinii from person to person was studied by detecting P. carinii-specific DNA in prospectively obtained noninvasive deep-nasal-swab samples from a child with a documented P. carinii pneumonia (PCP), his mother, two contact health care workers, and 30 hospital staff members who did not enter the patient's room (controls). Nested-DNA amplification was done by using oligonucleotide primers designed for the gene encoding the mitochondrial large subunit rRNA of rat P. carinii (P. carinii f. sp. carinii) that amplifies all forms of P. carinii and internal primers specific for human P. carinii (f. sp. hominis). P. carinii f. sp. hominis DNA was detected in samples from the patient and all of his contacts versus none of the 30 hospital staff members. The results, as previously shown in murine models of P. carinii pneumonia, document that person-to-person transmission of P. carinii is possible. This observation suggests that immunocompromised patients not on PCP prophylaxis should not enter the room of a patient with PCP, and it also raises the question as to whether healthy contacts can transmit the disease to immunocompromised patients at risk.
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Affiliation(s)
- S L Vargas
- Program in Microbiology, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago.
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Campos A, Díaz MA, Muñoz MP, Liñana JJ, Martínez M, Lanuza MD. Assessment of the inhalation technique in asthmatic patients: a comparative study of three aerosol devices. Allergol Immunopathol (Madr) 1998; 26:47-51. [PMID: 9645260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Local administration of drugs by means of aerosol device is widely used in the treatment of asthma. Nevertheless, the effectiveness of this method depends on an adequate inhalation technique (IT), which available evidence has shown to be rather problematic. The aim of this study was to assess IT in out-patients with bronchial asthma who frequently use aerosol therapy with Pressurized Metered dose inhalers (MDI), pressurized inhalers with spacer (MDI-S) and the Astra-Draco Turbuhaler system (TH). A sample of 150 adults with asthma were evaluated. These patients had been followed up for than two years and they often used one of the devices mentioned above. The IT has broken down into several steps for each procedure. Percentages of patients with one error in the IT were 50%, 44% and 42% for MDI, MDI-S and TH procedures, respectively. 18%, 20% and 14% of patients committed three errors in the IT, respectively. Differences detected were not significant. Seven patients committed errors in every step of the IT. In conclusion, the level of errors found in our study is high, similar to that cited in the existing literature. It is also roughly equivalent for the three devices tested. We believe that the proper teaching monitoring of IT skills is highly important in the treatment of bronchial asthma.
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Affiliation(s)
- A Campos
- Servicio de Alergia, Hospital Universitario La Fé, Valencia, Spain
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