Tropane alkaloids and calystegines as chemotaxonomic markers in the Solanaceae

This study assessed the occurrence and distribution of tropane alkaloids and calystegines in genera of the family Solanaceae to identify patterns of distribution and make evolutionary inferences. A database of tropane alkaloids and calystegines occurrences was constructed from the results of a search of scientific websites and a hand search of periodicals. The terms “Solanaceae”, “tropane alkaloids”, and “calystegines” were used as index terms for a full-text article search unrestricted by date of publications. The number of occurrence and chemical diversity indices were calculated and cluster analysis and principal components analysis were performed. Overall, 996 occurrences were reported, 879 of tropane alkaloids (88.3%) and 117 of calystegines (11.7%). The calystegines were significantly more relevant than tropane alkaloids for characterization of distinct groups of genera on both analyses performed here. This corroborates the trend toward a chemical dichotomy observed on database analysis and somewhat reinforces the correlation between geographic distribution and occurrence of secondary metabolites, as the presence of calystegines alone (without tropane alkaloids) was only reported in genera that have South America as their center of diversity.Este estudo analisou a ocorrência e a distribuição de alcaloides tropânicos e calisteginas em gêneros da família Solanaceae com o objetivo de identificar padrões de distribuição e fazer inferências evolutivas. Um banco de dados com ocorrências de alcaloides tropânicos e calisteginas foi elaborado a partir dos resultados de um levantamento em websites científicos e pela consulta direta em periódicos. Os termos “Solanaceae”, “alcaloides tropânicos” e “calisteginas” foram utilizados como indexadores para a busca de artigos na íntegra, sem restrição na data das publicações. O número de ocorrências e o índice de diversidade química foram calculados e análises de agrupamentos e de componentes principais foram realizadas. Um total de 996 ocorrências foi registrado, 879 de alcaloides tropânicos (88,3%) e 117 de calisteginas (11,7%). As calisteginas foram significativamente mais relevantes que os alcaloides tropânicos para a caracterização de distintos grupos de gêneros em ambas as análises realizadas. Isso corrobora a tendência de dicotomia química observada na análise do banco de dados, além de reforçar, de certa forma, a correlação entre a distribuição geográfica e a ocorrência de metabólitos secundários, visto que a presença exclusiva das calisteginas (sem alcaloides tropânicos) ocorre somente em gêneros cujo principal centro de diversidade é a América do Sul

Atividade antimicrobiana in vitro de óleos essenciais de Heterothalamus Less. (Asteraceae) contra espécies bacterianas e fúngicas clinicamente relevantes

Essential oils are natural, complex, and volatile compounds produced by the secondary metabolism of plants, which often serve as a protection against fungal or bacterial attack. Two species of the Asteraceae family, Heterothalamus alienus (Spreng.) O. Kuntze and Heterothalamus psiadioides Less., are used in folk medicine and recognised for their production of bioactive substances. However, little evidence of their antimicrobial properties currently exists. The aim of this study was to examine the in vitro antimicrobial activity of essential oils from H. alienus and H. psiadioides against clinically relevant bacterial and fungal species. The major chemical components of the essential oils used are terpene substances, of which β-pinene is the major component. Analysis of antibacterial activity was conducted using the disc diffusion method against 22 bacteria (18 gram-positive strains, including 13 enterococci strains resistant or multiresistant to antibiotics, and 4 Gram- -negative strains) and 9 fungi (6 yeasts and 3 filamentous fungi). The results indicated that essential oils from Heterothalamus species have a strong antimicrobial effect against gram-positive bacteria and yeasts, variable activity against filamentous fungi, and no activity against gram-negative bacteria. The most prominent results were observed in the sensitivity of Enterococcus faecalis (antibiotic- and multidrug-resistant strains) to the essential oils. In conclusion, this study demonstrates the potential for essential oils from Heterothalamus species for use as both an antiseptic and disinfectant in future approaches to control of clinically relevant gram-positive bacteria and fungi.Óleos essenciais são compostos naturais, complexos e voláteis produzidos no metabolismo secundário de plantas, os quais muitas vezes servem como proteção contra o ataque de fungos ou bactérias. Duas espécies da família Asteraceae, Heterothalamus alienus (Spreng.) O. Kuntze e Heterothalamus psiadioides Less., são utilizadas na medicina popular e reconhecidas por suas substâncias bioativas. Entretanto, existem poucas evidências sobre suas proprieda- -des antimicrobianas. O objetivo deste estudo foi avaliar a atividade antimicrobiana in vitro dos óleos essenciais de H. alienus e H. psiadioides contra cepas clinicamente relevantes de bactérias e fungos. Os principais componentes químicos dos óleos essenciais utilizados são as substâncias terpênicas, da qual o β-pineno é o componente majoritário. A análise da atividade antimicrobiana foi conduzida usando a técnica de difusão em disco contra 22 bactérias (18 gram-positivas, incluindo 13 enterococos resistentes ou multirresistentes a antibióticos, e 4 gram-negativas) e 9 fungos (6 leveduras e 3 fungos filamentosos). Nossos resultados indicaram que os óleos essenciais das espécies de Heterothalamus possuem forte atividade antimicrobiana contra bactérias gram-positivas e leveduras, atividade variável contra fungos filamentosos e nenhuma atividade contra bactérias gram-negativas. O resultado mais proeminentes observado foi a sensibilidade de Enterococcus faecalis resistentes e multirresistentes aos óleos essenciais. Em conclusão, este estudo demonstra o potencial dos óleos essenciais das espécies Heterothalamus para serem usados como antissépticos e desinfetantes, abordando o controle de bactérias gram-positivas e fungos de importância clínica

Social networks, language learning and language school student sojourners: a qualitative study

This thesis investigates individual language school student sojourners’ learning experiences in the UK. It takes into account the importance of learners learning through interaction with others in the target language community and recognises how learners’ social networks affect their language learning and use. There are many studies about students who study abroad for academic purposes and immigrant learners, but not many relating to individual language learners in private language schools. In order to fill this gap, this study focused on individual language school learners. With the intention of understanding how the social networks and language learning interact over time as part of their sojourner experience, I utilised different theoretical frameworks that have been applied to other groups of language learners and concluded that these frameworks are also applicable to private language school students. I recognised that in order to understand my participants’ learning experiences I needed to interact with them and also observe how they interacted with their social world. Therefore, formal interviews (semi-structured) and informal interviews (informal group meeting or chat) were the main methods for my study together with observation of interaction in various situations. This study identified the expectations that learners had with regard to the target language community, host families and native speakers’ attitudes towards foreign students, and the realisation that these expectations were higher than what was actually encountered. It also identified the steps the individual language learners took to overcome these disappointments and how they reconstructed their relationships with the target language and community respectively. In contrast with many previous studies which only focused on learning from native speakers, my study recognised that learners sometimes can have more interpersonal contact with their fellow students than native speakers. And consequently they benefit more from these contacts, in terms of language learning, than from native speakers. This thesis also helps language learners and language educators recognise basic theoretical frameworks which could help them evaluate the benefits and problems related to learning through interpersonal contact. And with this understanding learners will be able to facilitate their autonomous learning in the target language community

Volatile compounds of Baccharis punctulata, Baccharis dracunculifolia and Eupatorium laevigatum obtained using solid phase microextraction and hydrodistillation

In this work the qualitative chromatographic profiles of the volatile oil obtained with fresh chopped leaves of Baccharis punctulata, Baccharis dracunculifolia and Eupatorium laevigatum, using HS-SPME were compared with their hydrodistilled oils. Several Brazilian native plant species have not yet been studied regarding their volatile compounds composition. Conventional techniques employed for the investigation of volatile compounds, such as hydrodistillation, may impart chemical changes to the original oil composition. The use of HS-SPME provides alternative milder extraction conditions, preventing chemical transformations and supplying complementary information about volatiles composition. Coumarin and coumaran were detected by the first time among volatile components of E. laevigatum leaves after mechanical damage, only when using HS-SPME. Differences and similarities perceived between volatile compounds profiles using both extraction techniques are discussed, showing that they are complementary and may bring insight about fresh leaf volatiles playing infochemical roles and about chemical transformations caused by hydrodistillation

Screening antimycobacterial activity of Baccharis dracunculifolia, Centella asiatica, Lantana camara and Pterodonemarginatus

A investigação permanente de novas drogas antimicobacterianas é necessária no programa de erradicação da tuberculose e de outras doenças relacionadas com micobactérias. O objetivo deste estudo foi buscar novas fontes de drogas antimicobacterianas usando material vegetal. Neste estudo, 11 materiais de base vegetal (extratos, óleos essenciais e algumas frações) foram avaliados contra 5 espécies de micobactérias. Estes materiais foram obtidos a partir de 4 espécies de plantas medicinais tradicionalmente utilizadas como terapêutica geral para diferentes doenças e, especificamente, no tratamento de tuberculose (Baccharis dracunculifolia, Centella asiatica, Lantana camara, Pterodon emarginatus). Os ensaios foram realizados em microplacas com resazurina contra duas espécies do Complexo Mycobacterium tuberculosis e 3 espécies de micobactérias não tuberculosas. Os resultados mostraram o extrato hexânico e o óleo essencial de frutos de P. emarginatus como potenciais fontes para drogas antimicobacterianas contra quatro espécies de micobactérias testadas. A fração hexânica do extrato metanólico das folhas de C. asiatica também apresentou significativa inibição do crescimento de micobactérias apenas contra M. chelonae. Em conclusão, foi possível contribuir para as investigações de antimicobacterianos por apresentar três novas amostras de plantas com atividade antimicrobiana significativa contra quatro Mycobacterium spp e sugerir a realização de estudos futuros sobre as propriedades antimicobacterianas de frutos de P. emarginatus.The permanent investigation of new antimycobacterial drugs is necessary for the eradication programs of tuberculosis and other mycobacterium-related diseases. The aim of the present study is to search for new sources of antimycobacterial drugs using plant materials. In this study, 11 plant materials (extracts, essential oils and some fractions) obtained from 4 species of medicinal plants traditionally used as general therapeutics for different illnesses and specifically as treatment of tuberculosis, were evaluated using the microplate resazurin assay against 2 species of the Mycobacterium tuberculosis Complex and 3 nontuberculous mycobacteria. The results showed the hexane extract and the essential oil from fruits of Pterodon emarginatus (Vogel) as potential sources of antimycobacterial drugs against 4 species of tested mycobacteria. The hexane fraction of methanol extract from leaves of Centella asiatica also presented significant mycobacterial growth inhibition, but against M. chelonae only. In conclusion, it was possible to contribute to the antimycobacterial investigations by presenting three new samples of plants with significant antimicrobial activity against four Mycobacterium spp and suggest future studies about the antimycobacterial properties of fruits from P. emarginatus

Potencialidades morfogênicas de Copaifera langsdorffii Desf. (Fabaceae): super-hospedeira de herbívoros galhadores

Copaifera langsdorffii Desf. é super-hospedeira de insetos galhadores, apresentando diferentes morfotipos de galhas em seus órgãos vegetativos. Galhas esféricas de gema e laminar, em taça e de nervura foram estudadas de modo a verificar o potencial morfogênico da planta hospedeira. Como um todo, observa-se que os três sistemas de tecidos da hospedeira são alterados pelos galhadores e fenótipos distintos são gerados. O sistema de revestimento mantém-se uniestratificado, com a exceção das galhas esféricas de gema, que apresentam revestimento suberificado, indicando espessamento secundário. O sistema fundamental é formado por parênquima homogêneo com esclereídes isoladas ou agrupadas. Galhas em taça apresentam lignificação em torno da câmara larval, importante na proteção contra inimigos naturais. Os quatro morfotipos apresentam cavidades secretoras de sesquiterpenóides, substâncias associadas à proteção química. O sistema vascular é formado por feixes de pequenas dimensões em todos os tipos de galhas. O número de câmaras larvais e de insetos por câmara variou, sendo indicativo de competição entre a prole. Os diferentes galhadores geram alterações divergentes nos sistemas de tecidos vegetais, revelando as amplas potencialidades morfogênicas da super-hospedeira C. langsdorffii

CONSTRUÇÃO E ADAPTAÇÃO DO PROJETO APOLOBVM: RELATO DE EXPERIÊNCIA DE CRIAÇÃO DE METODOLOGIA DE ENSINO ATRAVÉS DE FERRAMENTAS TECNOLÓGICAS E INOVADORAS EM TEMPOS DE PANDEMIA DE COVID-19

220Resumo: O objetivo principal deste estudo descritivo é relatar a experiência vivenciada por um grupo de pesquisadores durante as atividades de desenvolvimento, construção e melhorias do projeto opensource APOLLO BMV sobre ventilação não invasiva, com o intuito de criar uma metodologia de ensino de impressão 3D e eletrônica através da plataforma Arduíno para intervenção educacional com adolescentes utilizando a ludicidade e aprendizagem criativa. As atividades foram desenvolvidas com professores pesquisadores de diferentes áreas formativas de duas instituições federais de ensino, durante os meses de fevereiro a maio de 2020 em meio a pandemia de Covid-19. Percebeu-se que o uso de ferramentas tecnológicas no espaço educacional com a inserção da Metodologia STEAM, configura-se como um instrumento para as transformações necessárias exigidas pelo mercado da Indústria 4.0 por proporcionar uma atitude mais ativa na aprendizagem, fazendo com que a o uso tecnologia motive e desenvolva o pensamento complexo.   Palavras Chaves: Covid-19. Educação. Metodologia STEAM. Aprendizagem Criativa. Ventilação não invasiva

Structural and Chemical Profiles of Myrcia splendens (Myrtaceae) Leaves Under the Influence of the Galling Nexothrips sp. (Thysanoptera)

Thysanoptera-induced galls commonly culminate in simple folding or rolling leaf gall morphotypes. Most of these galls are induced by members of the suborder Tubulifera, with only a few species of the suborder Terebrantia being reported as gall inducers. The Terebrantia, as most of the gall inducers, manipulates the host plant cellular communication system, and induces anatomical and biochemical changes in its host plant. In an effort to keep its homeostasis, the host plant reacts to the stimuli of the galling insect and triggers chemical signaling processes. In contrast to free-living herbivores, the signaling processes involving galling herbivores and their host plants are practically unknown. Current investigation was performed into two steps: first, we set the structural profile of non-galled and galled leaves, and looked forward to find potential alterations due to gall induction by an undescribed species of Nexothrips (suborder Terebrantia) on Myrcia splendens. Once oil glands had been altered in size and number, the second step was the investigation of the chemical profile of three tissue samples: (1) non-galled leaves of a control individual, (2) non-galled leaves of galled plants, and (3) galls. This third sample was divided into two groups: (3.1) galls from which the inducing thrips were manually removed and (3.2) galls macerated with the inducing thrips inside. The chemical profile was performed by gas chromatography/ mass spectrometric detector after headspace solid-phase extraction. The galling activity of the Nexothrips sp. on M. splendens culminates in mesophyll compactness interspersed to diminutive hypersensitive spots, development of air cavities, and the increase in size and number of the secretory glands. Seventy-two compounds were completely identified in the volatile profile of the three samples, from which, sesquiterpenes and aldehydes, pertaining to the “green leaf volatile” (GLVs) class, are the most abundant. The rare event of gall induction by a Terebrantia revealed discrete alterations toward leaf rolling, and indicated quantitative differences related to the plant bioactivity manipulated by the galling thrips. Also, the content of methyl salicylate has varied and has been considered a potential biomarker of plant resistance stimulated as a long-distance effect on M.splendens individuals