Síntese de tetrahidroquinolinas a partir da D-eritrose

Dissertação de mestrado em Química MedicinalEste trabalho teve como objetivo a síntese de tetrahidroquinolinas por reação da imina, resultante da combinação do aldeído da D-eritrose 54 com a p-metoxianilina, com vários 1,3-dienos. Eram dois os objetivos principais: (1) investigar se o grupo hidroxilo livre presente na componente D-eritrosilo seria capaz de induzir estéreoseletividade em cicloadições [4π+2π]; (2) efetuar a introdução de uma cadeia poliol na posição 2 da THQ. Foram postos a reagir dienófilos ricos em eletrões (dienófilos dadores), 1,3- butadienos substituídos, tais como, 2,3-dimetil-1,3-butadieno, (E)-5-bromo/hidroxilpenta- 1,3-dieno, (E)-buta-1,3-dien-1-ol, (buta-1,3-dien-2-iloxi)trimetilsilano e ainda o ciclopentadieno de modo a avaliar a seletividade da reação e perceber se o dienófilo reagiria através de uma reação Diels-Alder normal ou Diels-Alder inversa. Na maioria dos casos, foi necessária a presença de um ácido de Lewis para melhorar a reatividade. Nos casos do éter etilvinílico e do viniloxitrimetilsilano, foram obtidas misturas complexas sob condições ácidas. No entanto, foram obtidos os produtos esperados na ausência de catalisador. A maioria dos dienófilos mencionados acima originou uma única tetrahidroquinolina, resultante da reação de cicloadição inversa [4π+2π], com rendimentos variados (23-97%). No caso particular do (buta-1,3-dien-2- iloxi)trimetilsilano formou-se apenas o produto da reação de Diels-Alder normal (dieno mais ativado), com um rendimento de 53%, e no caso do 2,3-dimetil-1,3-butadieno formaram-se os dois produtos da cicloadição, numa proporção de 3:1, na qual o produto maioritário foi o resultante da reação de Diels-Alder normal.This work aimed the synthesis of tetrahydroquinolines by reaction of the imine resulting from combination of D-erythrose aldehyde 54 and p-methoxyaniline obtained in situ with various 1,3-dienes. This strategy had two main objectives: (1) to investigate whether the free hydroxyl group present in erythrosyl moiety would be able to induce stereoselectivity in [4π+2π] cycloadditions; (2) to introduce a polyol chain at position 2 of THQ compounds. Electron rich dienophiles (electron-donor dienophiles), substituted 1,3- butadienes, such as 2,3-dimethyl-1,3-butadiene, (E)-5-bromo/hydroxyl-penta-1,3- diene, (E)-buta-1,3-dien-1-ol, (buta-1,3-dien-2-yloxy)trimethylsilane and cyclopentadiene were reacted to evaluate the selectivity of the reaction and to find if the dienophile reacts through normal or reverse electron-demand cycloaddition. In most cases, the presence of a Lewis acid was required to improve the reactivity. In the case of ethyl vinyl ether and vinyloxytrimethylsilane, complex mixtures were obtained under acidic conditions. It was, however, possible to obtain the expected product in the absence of catalyst. Most of dienophiles mentioned above gave a single tetrahydroquinoline product resulting from reverse electron-demand [4π+2π] cycloaddition, obtained in variable yields: 23-97%. In the particular case of (buta-1,3-dien-2-yloxy)trimethylsilane only the product of the normal Diels-Alder reaction was obtained, in 53% yield; and in case of 2,3-dimethyl-1,3-butadiene two products were formed, in a 3:1 ratio, in which the major compound resulted from normal Diels-Alder reaction

Total facial selectivity in 2π+4π reactions of (2R,4S,5R)-4-((E)-((4-Methoxyphenyl)imino)methyl)-2-phenyl-1,3-dioxan-5-ol to electron-rich dienophiles

Tetrahydroquinoline (THQ) is an important structural unit present in various natural products and pharmaceutical agents having a large range of biological activities. Many approaches have been developed for the construction of THQ scaffold. Among these, the inverse electron demand hetero-Diels-Alder reaction1 or its ionic version2 is regarded as a powerful tool. The imine 3 is generated in situ from D-erythrose and p-methoxy-aniline. When the reaction is finished dienophiles were added at – 78 ºC giving products in moderate to high yields, with formation of a single diastereoisomer. In this work BF3·Et2O3 used as catalyst is supposed to help to induce facial selectivity in 2π+4π reactions. The boron atom is able to form a bridge between the oxygen and nitrogen atoms, neighbor in space. In this way rotation around bound a would be avoided, and the structure would obtain some rigidity. According to X-ray crystallography of product 4a, dienophiles approach the imine by the re face. It is likely that the packing of the dienophile hydrogens with diene’s H-4 explains the si face impediment. Reactions of the imine with vinyl ether and (E)-5-bromopenta-1,3-diene occurred in the absence of catalyst, but a single product was also formed. This was rationalized by an intramolecular hydrogen bond between the alcohol and the nitrogen atom that would confer to the structure the same rotational restriction. When 2,3-dimethylbutadiene was used as dienophile a mixture of inverse and normal polarity 2π+4π reaction product occurred in a 1:2 ratio.The FCT for financial support PTDC/EQF-MED/1671/2012, the national network of NMR (PTNMR, Bruker Avance III 400-Univ. Minho) and FEDER-COMPETE-QREN-EU funding the Department Chemistry-UM.info:eu-repo/semantics/publishedVersio

Evaluación de la cadera de amputados transfemorales durante contracción isométrica en dinamómetro isocinético

INTRODUÇÃO: A amputação transfemoral leva a uma série de alterações funcionais na biomecânica corporal que podem interferir no cotidiano do amputado, podendo gerar, ainda, padrões de postura e de marcha para compensar a perda do membro.OBJETIVO: Avaliar e comparar as respostas musculares do quadril de amputados transfemorais durante contrações isométricas, utilizando-se um dinamômetro isocinético.MÉTODO: Participaram do estudo quatro voluntários, sendo dois amputados e dois não amputados. Foi realizada avaliação isométrica no dinamômetro isocinético nas angulações de 30 e 60 graus com duração de 10 segundos. Cada série tinha um total de seis repetições, contabilizando três flexões e três extensões e um intervalo de 20 segundos para cada repetição.RESULTADOS: O membro amputado apresenta menor pico de torque em relação ao não amputado, tanto na flexão como extensão do quadril a 30 e a 60 graus.CONCLUSÃO: Devido à amputação, os indivíduos apresentam menor força muscular de quadril, fato que pode prejudicar as atividades diárias como caminhar, sentar e levantar, e subir e descer escadas.INTRODUCTION: Transfemoral amputation leads to a series of functional changes in the body biomechanics that can interfere with the daily life of the amputee, generating patterns of posture and gait to compensate for the loss of the limb.OBJECTIVE: This study aims to evaluate and compare the muscular responses of the hip during isometric contractions in transfemoral amputees, using an isokinetic dynamometer.METHOD: The study included four volunteers, two amputees and two non-amputees. Evaluation was performed using an isokinetic dynamometer in isometric angles of 30 and 60 degrees of 10 seconds duration. Each series was made of six repetitions, composed by three pushups and three extensions with a 20 seconds interval between each sequence.RESULTS: The amputated limb showed a lower peak torque compared to the non-amputee, both in flexion and in extension of the hip at 30 and 60 degrees.CONCLUSION: Due to amputation, individuals have less hip muscle strength, which may impair daily activities such as walking, sitting and standing, climbing and descending stairs.INTRODUCCIÓN: La amputación transfemoral lleva a una serie de alteraciones funcionales en la biomecánica corporal que pueden interferir en el cotidiano del amputado pudiendo generar, además, estándares de postura y de marcha para compensar la pérdida del miembro.OBJETIVO: Evaluar y comparar las respuestas musculares de la cadera de amputados transfemorales durante contracciones isométricas, utilizándose un dinamómetro isocinético.MÉTODO: Participaron en el estudio cuatro voluntarios, siendo dos amputados y dos no amputados. Fue realizada evaluación isométrica en el dinamómetro isocinético en las angulaciones de 30 y 60 grados con duración de 10 segundos. Cada serie tenía un total de seis repeticiones, contabilizando tres flexiones y tres extensiones y un intervalo de 20 segundos para cada repetición.RESULTADOS: El miembro amputado presenta menor pico de torque en relación al no amputado, tanto en la flexión como extensión de la cadera a 30 y a 60 grados.CONCLUSIÓN: Debido a la amputación, los individuos presentan menor fuerza muscular de cadera, hecho que puede perjudicar las actividades diarias como caminar, sentarse y levantarse, subir y bajar escaleras

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

The Genome of Anopheles darlingi, the main neotropical malaria vector

Anopheles darlingi is the principal neotropical malaria vector, responsible for more than a million cases of malaria per year on the American continent. Anopheles darlingi diverged from the African and Asian malaria vectors ∼100 million years ago (mya) and successfully adapted to the New World environment. Here we present an annotated reference A. darlingi genome, sequenced from a wild population of males and females collected in the Brazilian Amazon. A total of 10 481 predicted protein-coding genes were annotated, 72% of which have their closest counterpart in Anopheles gambiae and 21% have highest similarity with other mosquito species. In spite of a long period of divergent evolution, conserved gene synteny was observed between A. darlingi and A. gambiae. More than 10 million single nucleotide polymorphisms and short indels with potential use as genetic markers were identified. Transposable elements correspond to 2.3% of the A. darlingi genome. Genes associated with hematophagy, immunity and insecticide resistance, directly involved in vectorhuman and vectorparasite interactions, were identified and discussed. This study represents the first effort to sequence the genome of a neotropical malaria vector, and opens a new window through which we can contemplate the evolutionary history of anopheline mosquitoes. It also provides valuable information that may lead to novel strategies to reduce malaria transmission on the South American continent. The A. darlingi genome is accessible at www.labinfo.lncc.br/index.php/anopheles- darlingi. © 2013 The Author(s)

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest

Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ

Catálogo Taxonômico da Fauna do Brasil: setting the baseline knowledge on the animal diversity in Brazil

The limited temporal completeness and taxonomic accuracy of species lists, made available in a traditional manner in scientific publications, has always represented a problem. These lists are invariably limited to a few taxonomic groups and do not represent up-to-date knowledge of all species and classifications. In this context, the Brazilian megadiverse fauna is no exception, and the Catálogo Taxonômico da Fauna do Brasil (CTFB) (http://fauna.jbrj.gov.br/), made public in 2015, represents a database on biodiversity anchored on a list of valid and expertly recognized scientific names of animals in Brazil. The CTFB is updated in near real time by a team of more than 800 specialists. By January 1, 2024, the CTFB compiled 133,691 nominal species, with 125,138 that were considered valid. Most of the valid species were arthropods (82.3%, with more than 102,000 species) and chordates (7.69%, with over 11,000 species). These taxa were followed by a cluster composed of Mollusca (3,567 species), Platyhelminthes (2,292 species), Annelida (1,833 species), and Nematoda (1,447 species). All remaining groups had less than 1,000 species reported in Brazil, with Cnidaria (831 species), Porifera (628 species), Rotifera (606 species), and Bryozoa (520 species) representing those with more than 500 species. Analysis of the CTFB database can facilitate and direct efforts towards the discovery of new species in Brazil, but it is also fundamental in providing the best available list of valid nominal species to users, including those in science, health, conservation efforts, and any initiative involving animals. The importance of the CTFB is evidenced by the elevated number of citations in the scientific literature in diverse areas of biology, law, anthropology, education, forensic science, and veterinary science, among others