O gênero Psidium é pertencente à família Myrtaceae e compreende importantes espécies botânicas, destacando-se a goiabeira (Psidium guajava L.). O óleo essencial (OE) desta espécie já conduziu diversos trabalhos científicos devido a sua composição química e propriedades farmacológicas, destacando-se a sua ação antifúngica e atividades antimicrobianas. Neste trabalho, duas variedades de Psidium, Psidium guajava var. pomifera (Paluma) e Psidium guajava var. pyrifera (Kumagai), foram coletadas em diferentes localidades do município de Itacoatiara – AM, o OE das folhas foram avaliadas quanto à composição química e atividade antimicrobiana. A extração do óleo essencial foi realizada por hidrodestilação em aparelho do tipo Clevenger durante 4 horas, as análises quantitativas e qualitativas foram executadas por cromatografia gasosa acoplada à espectrometria de massa. As atividades antimicrobianas foram avaliadas utilizando o teste in vitro sobre a inibição do crescimento bacteriano de Escherichia coli (Migula 1895) Castellani e Chalmers 1919, Salmonella sp e Staphylococcus aureus Rosenbach 1884 e do crescimento micelial dos fitopatógenos Candida albicans (C.P. Robin) Berkhout 1923 e Candida parapsilosis (Ashford) Langeron & Talice 1932. A composição química revelou a presença dos monoterpenos: D_limoneno, α-pineno, 1,8 – cineol, e dos sequiterpenos: trans-nerolidol, trans-cariofileno, óxido de cariofileno e α-Humuleno como constituintes majoritários nas amostras avaliadas. Em relação aos testes biológicos realizados foi possível observar atividade antimicrobiana em todas as cepas estudadas. Diante dos resultados, conclui-se que óleos essenciais destas variedades de P. guajava apresentam atividades promissoras e podem ser consideradas como nova fonte de compostos bioativos antimicrobianos.

Information and communication technologies (ICTs) are ubiquitous in our everyday lives as well as in educational contexts, much more so after the onset of the Covid-19 pandemic. The use of ICTs in education, e.g., virtual laboratories, is of great importance to support the teaching of chemistry. Given the difficulties secondary school students encounter in understanding organic chemistry topics, this research aimed at investigating whether the use of a software program could improve teaching and promote student learning of content related to organic compounds. To this end, the data were collected by means of a pre- and a post-intervention questionnaire. The study was conducted at a public secondary school in Itacoatiara, AM, Brazil, with 3rd-year (final year) students. The software programs IrYdium Chemistry Lab, LAPEQ-USP (Laboratory of Research in Chemistry Teaching and Educational Technologies, University of São Paulo), and Simulations for Chemistry were employed to introduce the participating students to a chemistry lab and to simulate lab practices involving chromatography experiments. The analysis of the collected data suggests that the use of virtual labs promoted the participants’ motivation to learn organic chemistry as well as ability to integrate concepts taught in the classroom to aspects of their everyday lives. The participating students also reported that they would like to use other virtual lab programs to study chemistry, thus constituting new ways of learning beyond the classroom.

In view of the challenges encountered in education, especially those posed by the ongoing SARS-CoV-2 pandemic and resulting school shutdowns, teachers and school administrators have looked for alternatives to conventional face-to-face teaching methods. This study aimed at advancing the teaching of chemistry by means of a contextualized and interdisciplinary approach integrating the curriculum topic “Solar System” to general chemistry concepts and theories. To this end, online and face-to-face classes, supported by a guidebook, were conducted about the subject matter in question at a public secondary school in Itacoatiara, AM, Brazil. The participating students responded to two questionnaires, an exploratory questionnaire and an evaluation questionnaire before and after the intervention, respectively. The guidebook was made available to participants both face-to-face and virtually (Google Classroom). The results suggest that the use of contextualization in classes about the solar system was capable of motivating the participants to learn chemistry concepts and theories. In addition, the results indicate that the students would like to experience other chemistry teaching methods that promote learning beyond the classroom.

RESUMOO presente projeto desenvolveu um jogo de tabuleiro de baixo custo visando o ensino da nomenclatura e identificação dos grupos funcionais de compostos orgânicos. As concepções dos estudantes sobre as atividades realizadas foram avaliadas através dos

This work aimed to contribute to the chemotaxonomic study and determination of antioxidant potential of species of the genus Vismia, which until now has not had any detailed studies in this area. Thus, the fruits of the species, V. cayennensis, V. guianensis and V. aff. guianensis were collected in terra firme forest around Itacoatiara-AM. Organic extracts from Vismia spp. were obtained with solvents in increasing order of polarity and submitted to chemical analysis by mass spectrometry with electrospray ionization (ESI-MS) for the chemometric and biological study, regarding the antioxidant potential against the DPPH radical and the total phenolic content. From the chemometric analysis it was possible to observe the chemical similarity between the samples of hexane extract (EH-VG) and dichloromethane (ED-VG) of the species V. guianensis, and hexane (EH-VX), dichloromethane (ED-VX), ethyl acetate (EA-VX) and methanolic acetate (EM-VX) from the species V. aff. guianensis. As for the antioxidant test, the methanol extract (EMVX) stood out for having a high content of total phenolics (1592.6 ± 3.8 μM ET) compared to the other extracts.