RESUMEN
Novel transmission routes can allow infectious diseases to spread, often with devastating consequences. Ectoparasitic varroa mites vector a diversity of RNA viruses, having switched hosts from the eastern to western honey bees (Apis cerana to Apis mellifera). They provide an opportunity to explore how novel transmission routes shape disease epidemiology. As the principal driver of the spread of deformed wing viruses (mainly DWV-A and DWV-B), varroa infestation has also driven global honey bee health declines. The more virulent DWV-B strain has been replacing the original DWV-A strain in many regions over the past two decades. Yet, how these viruses originated and spread remains poorly understood. Here, we use a phylogeographic analysis based on whole-genome data to reconstruct the origins and demography of DWV spread. We found that, rather than reemerging in western honey bees after varroa switched hosts, as suggested by previous work, DWV-A most likely originated in East Asia and spread in the mid-20th century. It also showed a massive population size expansion following the varroa host switch. By contrast, DWV-B was most likely acquired more recently from a source outside East Asia and appears absent from the original varroa host. These results highlight the dynamic nature of viral adaptation, whereby a vector's host switch can give rise to competing and increasingly virulent disease pandemics. The evolutionary novelty and rapid global spread of these host-virus interactions, together with observed spillover into other species, illustrate how increasing globalization poses urgent threats to biodiversity and food security.
Asunto(s)
Virus ARN , Varroidae , Abejas , Animales , Virus ARN/genética , Evolución Biológica , Interacciones Microbiota-Huesped , FilogeografíaRESUMEN
In 1977, a sample of diseased adult honeybees (Apis mellifera) from Egypt was found to contain large amounts of a previously unknown virus, Egypt bee virus, which was subsequently shown to be serologically related to deformed wing virus (DWV). By sequencing the original isolate, we demonstrate that Egypt bee virus is in fact a fourth unique, major variant of DWV (DWV-D): more closely related to DWV-C than to either DWV-A or DWV-B. DWV-A and DWV-B are the most common DWV variants worldwide due to their close relationship and transmission by Varroa destructor. However, we could not find any trace of DWV-D in several hundred RNA sequencing libraries from a worldwide selection of honeybee, varroa and bumblebee samples. This means that DWV-D has either become extinct, been replaced by other DWV variants better adapted to varroa-mediated transmission, or persists only in a narrow geographic or host range, isolated from common bee and beekeeping trade routes.
Asunto(s)
Virus ARN , Varroidae , Animales , Abejas , Virus ADN , Egipto , Virus ARN/genéticaRESUMEN
One hundred and twenty samples of breast milk were collected from five northern governorates and districts in Jordan in 2019 and 2020 to monitor results for organochlorine pesticides as organic contaminants. The results showed that 36 samples (30%) of total 120 analyzed samples were contaminated as follows: 16 samples (13.3%) were contaminated with dieldrin, 4 samples (3.3%) with p,p'-DDE, 4 samples (3.3%) with p,p'-DDD, 8 samples (6.7%) with p,p'-DDT and 4 samples (3.3%) with o,p'-DDE. Comparing results of the current study with those of 2015 study, no residues for the HCHs in 2019/2020 study have been detected, an increase in the DDTs occurred and an increase in the cyclodiens in the 2019/2020 compared to the 2015 study.
Asunto(s)
Hidrocarburos Clorados , Residuos de Plaguicidas , Plaguicidas , DDT/análisis , Monitoreo del Ambiente , Femenino , Humanos , Hidrocarburos Clorados/análisis , Jordania , Leche Humana/química , Residuos de Plaguicidas/análisis , Plaguicidas/análisisRESUMEN
5-Cyanoimidazole was identified as an inexpensive ligand for nickel-catalyzed cross-electrophile couplings by screening a diverse set of pharmaceutical compound library. A strategic screening approach led to the discovery of this novel ligand, which was successfully applied in the preparation of various alkylated arene products with good to high yields. Furthermore, the properties of this ligand allowed expanding the scope of reductive couplings to challenging substrates, such as sterically hindered neopentyl halides, which are known to generate motifs that are prevalent in biologically active molecules.
RESUMEN
An efficient general methodology for the synthesis of 4-quinolinyl ethers is demonstrated via a highly reactive SNAr reaction of 4-quinolinyl sulfones with a range of structurally diversified 1°, 2°, and 3° alcohols with a wide substrate scope and high yields. By adapting this methodology, a convergent synthesis of a complex target of HCV NS3/4a protease inhibitor BI 201420 was accomplished.
Asunto(s)
Hepatitis C , Proteínas no Estructurales Virales , Antivirales , Éteres , Hepacivirus , Humanos , Inhibidores de Proteasas/farmacología , SulfonasRESUMEN
Enantioenriched aldehydes are produced through asymmetric hydroformylation of styrene derivatives using BIBOP-type ligands. The featured example is enantioselective synthesis of 4-methyl-3,4-dihydroisocoumarin, which was prepared in a 95.1:4.9 enantiomeric ratio from asymmetric hydroformylation of ethyl 2-vinylbenzoate followed by in situ lactonization during the reduction process. The conditions are compatible with both electron-rich and electron-poor substituents.
Asunto(s)
Cumarinas/síntesis química , Estireno/química , Aldehídos/química , Cumarinas/química , Ligandos , Estructura Molecular , EstereoisomerismoRESUMEN
The application of a Buchwald's third generation palladacycle containing a dihydrobenzooxaphosphole-based ligand (e.g., BIDIME) was reported in the Suzuki cross-coupling reaction. Using flow technology, high yield and reproducible Suzuki cross-coupling reaction for one of our key intermediates was achieved with Pd loadings as low as 0.5 mol %. This continuous flow approach overcomes catalyst deactivation and scale dependence issues that can be a problem in some traditional batch-mode operations and responds to the challenge of improving process greenness.
RESUMEN
A chromatography-free, asymmetric synthesis of the C2-symmetric P-chiral diphosphine t-Bu-SMS-Phos was developed using a chiral auxiliary-based approach in five steps from the chiral auxiliary in 36% overall yield. Separtion and recovery of the auxiliary were achieved with good yield (97%) to enable recycling of the chiral auxiliary. An air-stable crystalline form of the final ligand was identified to enable isolation of the final ligand by crystallization to avoid chromatography. This synthetic route was applied to prepare up to 4 kg of the final ligand. The utility of this material was demonstrated in the asymmetric hydrogenation of trifluoromethyl vinyl acetate at 0.1 mol % Rh loading to access a surrogate for the pharmaceutically relavent chiral trifluoroisopropanol fragment in excellent yield and enantiomeric excess (98.6%).
RESUMEN
One hundred samples of mother breast milk were gathered from six middle governorates and districts in Jordan in 2013/2014 to monitor Organochlorine pesticides pollutants. The results showed clearly that banned organochlorine pesticides are still detected in the monitored samples in low concentration despite banning of these persistent pollutants in Jordan since 36 years ago. However, the results indicated that 1% of the contaminated samples contained ß-HCH, 5% γ-HCH, 3% p,p'-DDD, 2% heptachlor, 45% p,p'-DDE and 3% p,p'-DDT. In addition, these monitored samples had no residues of aldrin, dieldrin, α-endosulfan, ß-endosulfan, HCB, o,p'-DD, o,p'-DDT and o,p'-DDE. In conclusion, there was a decline in the residues of Organochlorine pesticides, particularly DDT group members.
Asunto(s)
Exposición a Riesgos Ambientales/estadística & datos numéricos , Hidrocarburos Clorados/metabolismo , Leche Humana/metabolismo , Residuos de Plaguicidas/metabolismo , Plaguicidas/metabolismo , Aldrín/análisis , Aldrín/metabolismo , DDT , Diclorodifenil Dicloroetileno/análisis , Diclorodifenil Dicloroetileno/metabolismo , Dieldrín/análisis , Dieldrín/metabolismo , Endosulfano/análisis , Endosulfano/metabolismo , Heptacloro/análisis , Heptacloro/metabolismo , Hexaclorociclohexano/metabolismo , Humanos , Hidrocarburos Clorados/análisis , Jordania , Leche Humana/química , Mitotano/análogos & derivados , Mitotano/metabolismo , Residuos de Plaguicidas/análisis , Plaguicidas/análisisRESUMEN
A concise asymmetric synthesis of an 11ß-HSD-1 inhibitor has been achieved using inexpensive starting materials with excellent step-economy at low catalyst loadings. The catalytic enantioselective total synthesis of 1 was accomplished in 7 steps and 38% overall yield aided by the development of an innovative, sequential strategy involving Pd-catalyzed pyridinium C-H arylation and Ir-catalyzed asymmetric hydrogenation of the resulting fused tricyclic indenopyridinium salt highlighted by the use of a unique P,N-ligand (MeO-BoQPhos) with 1000 ppm of [Ir(COD)Cl]2.
Asunto(s)
11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/antagonistas & inhibidores , Inhibidores Enzimáticos/síntesis química , Piperidinas/síntesis química , Piperidinas/farmacología , 11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/metabolismo , Catálisis , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Humanos , Hidrogenación , Iridio/química , Conformación Molecular , Paladio/química , Piperidinas/química , EstereoisomerismoRESUMEN
Apis mellifera syriaca is the native honeybee subspecies of Jordan and much of the Levant region. It expresses behavioral adaptations to a regional climate with very high temperatures, nectar dearth in summer, attacks of the Oriental wasp and is resistant to Varroa mites. The A. m. syriaca control reference sample (CRS) in this study was originally collected and stored since 2001 from "Wadi Ben Hammad", a remote valley in the southern region of Jordan. Morphometric and mitochondrial DNA markers of these honeybees had shown highest similarity to reference A. m. syriaca samples collected in 1952 by Brother Adam of samples collected from the Middle East. Samples 1-5 were collected from the National Center for Agricultural Research and Extension breeding apiary which was established for the conservation of A. m. syriaca. Our objective was to determine the success of an A. m. syriaca honey bee conservation program using genomic information from an array-based comparative genomic hybridization platform to evaluate genetic similarities to a historic reference collection (CRS). Our results had shown insignificant genomic differences between the current population in the conservation program and the CRS indicated that program is successfully conserving A. m. syriaca. Functional genomic variations were identified which are useful for conservation monitoring and may be useful for breeding programs designed to improve locally adapted strains of A. m. syriaca.
Asunto(s)
Abejas/genética , Evolución Biológica , Animales , Cromosomas de Insectos , Hibridación Genómica Comparativa , Amplificación de Genes , Eliminación de Gen , Genes de Insecto , Genoma de los InsectosRESUMEN
An efficient Negishi cross-coupling was developed for the synthesis of the biaryl axes present in useful P-chiral dihydrobenzooxaphosphole ligands. This approach has allowed for the synthesis of new derivatives of these ligands that were not accessible by the previous route employing Suzuki-Miyaura cross-coupling. The use of Pd2(dba)3/BI-DIME as the catalyst system affords the desired biaryl compounds in good yields with excellent rates and with catalyst loadings as low as 0.25 mol %.
RESUMEN
An efficient synthesis of the enantiomerically pure 3,3'-bis-arylated BINOL derivatives is accomplished through the palladium-catalyzed Suzuki-Miyaura coupling of the unprotected 3,3'-dibromo-BINOL with complete retention of enantiopurity. The active catalyst system Pd(OAc)2/BI-DIME has enabled mild reaction conditions at palladium loads as low as 500 ppm.
RESUMEN
A nickel-catalyzed Heck cyclization for the construction of quaternary stereocenters is reported. This transformation is demonstrated in the synthesis of 3,3-disubstituted oxindoles, which are prevalent motifs seen in numerous biologically active molecules. The method shows broad scope, proceeds in synthetically useful yields, and provides a rare means to construct stereochemically complex frameworks by nonprecious-metal catalysis.
RESUMEN
BACKGROUND: Identification of bacteria may be based on sequencing and molecular analysis of a specific locus such as 16S rRNA, or a set of loci such as in multilocus sequence typing. In the near future, healthcare institutions and routine diagnostic microbiology laboratories may need to sequence the entire genome of microbial isolates. Therefore we have developed Reads2Type, a web-based tool for taxonomy identification based on whole bacterial genome sequence data. RESULTS: Raw sequencing data provided by the user are mapped against a set of marker probes that are derived from currently available bacteria complete genomes. Using a dataset of 1003 whole genome sequenced bacteria from various sequencing platforms, Reads2Type was able to identify the species with 99.5 % accuracy and on the minutes time scale. CONCLUSIONS: In comparison with other tools, Reads2Type offers the advantage of not needing to transfer sequencing files, as the entire computational analysis is done on the computer of whom utilizes the web application. This also prevents data privacy issues to arise. The Reads2Type tool is available at http://www.cbs.dtu.dk/~dhany/reads2type.html.
Asunto(s)
Bacterias/clasificación , Bacterias/genética , Genoma Bacteriano , Internet , Programas Informáticos , Proteínas Bacterianas/genética , Benchmarking , Clasificación , ADN Bacteriano/genética , Bases de Datos Genéticas , Tipificación de Secuencias Multilocus , ARN Ribosómico 16S/genéticaRESUMEN
A practical and efficient synthesis of a complex chiral atropisomeric HIV integrase inhibitor has been accomplished. The combination of a copper-catalyzed acylation along with the implementation of the BI-DIME ligands for a ligand-controlled Suzuki cross-coupling and an unprecedented bis(trifluoromethane)sulfonamide-catalyzed tert-butylation renders the synthesis of this complex molecule robust, safe, and economical. Furthermore, the overall synthesis was conducted in an asymmetric and diastereoselective fashion with respect to the imbedded atropisomer.
Asunto(s)
Inhibidores de Integrasa VIH/síntesis química , Integrasa de VIH/química , VIH/enzimología , Acilación , Catálisis , Cobre/química , Integrasa de VIH/metabolismo , Inhibidores de Integrasa VIH/química , Humanos , Ligandos , Estereoisomerismo , Sulfonamidas/químicaRESUMEN
Synthesis of the electron-rich 2-substituted-6-(phenylsulfonyl)pyridines is presented. A series of air-stable, tunable, P-chiral pyridyl-dihydrobenzooxaphosphole ligands were designed and synthesized by a diastereoselective S(N)Ar substitution of the corresponding sulfonyl pyridines. The ligands were successfully applied in the Ir-catalyzed asymmetric hydrogenation of unfunctionalized alkenes with good enantioselectivities.
Asunto(s)
Iridio/química , Compuestos de Fósforo/síntesis química , Piridinas/síntesis química , Alquenos , Catálisis , Hidrogenación , Ligandos , Estructura Molecular , Compuestos de Fósforo/química , Piridinas/química , EstereoisomerismoRESUMEN
Air-stable P-chiral dihydrobenzooxaphosphole oxazoline ligands were designed and synthesized. When they were used in the iridium-catalyzed asymmetric hydrogenation of unfunctionalized 1-aryl-3,4-dihydronaphthalenes under one atmosphere pressure of H2 , up to 99:1 e.r. was obtained. High enantioselectivities were also observed in the reduction of the exocyclic imine derivatives of 1-tetralones.
Asunto(s)
Hidrógeno/química , Iridio/química , Oxazoles/química , Catálisis , Hidrogenación , Iminas/química , Modelos Moleculares , EstereoisomerismoRESUMEN
An enantioselective copper-catalyzed asymmetric conjugate addition of Me2Zn to (Z)-nitroalkenes led to the formation of all-carbon quaternary stereogenic centers with high stereoselectivity. The key features of the new method are the unprecedented use of [(MeCN)4Cu]PF6 in conjunction with the Hoveyda ligand L1 and the use of (Z)-nitroalkene substrates so that undesired nitroalkene isomerization is minimized and enantioselectivity is enhanced dramatically. We also describe a novel, practical, and highly (Z)-selective nitroalkene synthesis.
Asunto(s)
Alquenos/química , Cobre/química , Nitrógeno/química , Compuestos Organometálicos/química , Catálisis , Cromatografía Líquida de Alta Presión , Isomerismo , Ligandos , EstereoisomerismoRESUMEN
The development of zinc-mediated and -catalyzed asymmetric propargylations of trifluoromethyl ketones with a propargyl borolane and the N-isopropyl-l-proline ligand is presented. The methodology provided moderate to high stereoselectivity and was successfully applied on a multikilogram scale for the synthesis of the Glucocorticoid agonist BI 653048. A mechanism for the boron-zinc exchange with a propargyl borolane is proposed and supported by modeling at the density functional level of theory. A water acceleration effect on the zinc-catalyzed propargylation was discovered, which enabled a catalytic process to be achieved. Reaction progress analysis supports a predominately rate limiting exchange for the zinc-catalyzed propargylation. A catalytic amount of water is proposed to generate an intermediate that catalyzes the exchange, thereby facilitating the reaction with trifluoromethyl ketones.