The essential oils of the leaves and fine stems of Psidium acutangulum, P. striatulum, P. guineense and P. guajava were obtained by hydrodistillation and analysed by GC-MS. The main compounds identified in the oil of P. acutangulum were α-pinene (14.8%), 1,8-cineole (12.9%) and β-pinene (10.1%). The oil of P. striatulum was dominated by β-caryophyllene (28.6%), α-selinene (7.7%), caryophyllene oxide (7.6%) and β-selinene (7.4%). The major constituents found in the oil of P. guineense were β-bisabolol (17.4%), limonene (6.8%) and epi-α-bisabolol (6.7%). The oil of P. guajava was dominated by α-pinene (23.9%), 1,8-cineole (21.4%) and β-bisabolol (9.2%).

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A falta de disponibilidade de energia elétrica é um dos principais motivos pelo baixo Índice de Desenvolvimento Humano das comunidades isoladas localizadas na Amazônia. O biodiesel produzido a partir de óleos vegetais extraídos de espécies oleaginosas nativas de forma sustentada é uma das melhores alternativas energéticas para a região. O tucumã do amazonas, Astrocaryum aculeatum, é uma espécie de palmeira que produz um fruto muito apreciado na região, a partir do qual se obtém uma amêndoa com alto teor de óleo. Nesse estudo, foi avaliada a produção de biodiesel etílico, a partir de diferentes lotes de óleos de tucumã do amazonas, com índices de acidez baixos e elevados, pela transesterificação por catálise básica e ácida homogêneas, respectivamente. Na catálise ácida, foram testados HCl e H 2 SO 4 como catalisadores nas concentrações de 0,0625 a 1,000 M, empregando etanol hidratado na proporção molar de 1:6 e a reação conduzida a 90 ºC por 24 h. Na catálise básica, foram testados NaOH e KOH, nas proporções de 0,5 a 2,0 %, empregando etanol anidro na proporção molar de 1:12 e a reação conduzida a 80 ºC por 2 h. O biodiesel obtido em cada experimento foi analisado por métodos físicos (massa específica) e cromatográficos (CLAE em fase reversa). Análises cromatográficas indicaram que as melhores conversões foram alcançadas por amostras de biodiesel com massas específicas inferiores a 0,87 g.cm -1 . As amostras de biodiesel obtidas com melhor qualidade foram obtidas utilizando-se os catalisadores ácidos a 1,0 M com rendimentos superiores a 90%. No caso da catálise básica, obteve-se biodiesel de boa qualidade empregando-se o catalisador NaOH a 2,0%, porém com rendimento inferior a 60 %. Contudo, em ambos os casos, foi possível identificar um excelente potencial de produção de biocombustível, a partir do óleo das amêndoas de tucumã.PALAVRAS-CHAVE: Sustentabilidade, Arecaceae, Energia elétrica, Amazônia. The use of tucumã of amazonas kernel oil in the biodiesel productionABSTRACT the shortage of electricity is a major reason for the low Human Development index of isolated communities located in the Amazon basin. the biodiesel produced from vegetable oils extracted from oil seeds native species, in a sustainable way, is one of the best alternative energy for the region. the "tucumã of amazonas", Astrocaryum aculeatum, is an Amazon palm tree that produces a much appreciated fruit in the region, from which it obtains kernels that have high content in oil. in this study, we evaluated the production of ethyl biodiesel, from different batches of oil obtained from "tucumã of amazonas" kernels with high and low acidity by the transesterification process acidic and basic catalysis, respectively. Different acid catalysts (HCl and H 2 SO 4 ) and concentrations of each acid (from 0.0625 to 1.000 M) were tested, with ethanol at molar ratio of 1:6 at 90º C for 24 h. in the basic catalysis, NaOH and KOH were tested at the concentration range of 0.5 to 2.0 % with anhydrous ethanol with molar ratio 1:12 and the reactions took place at ...

This paper contains data on the chemical composition of the essential oils of 22 leaf samples of Piper marginatum Jacq. collected in different areas and ecosystems of the brazilian Amazon, as well as an overview of the available literature. The species presents a large synonymy based on their different leaf characteristics and distinct scents where some of them smell like anise or very close compounds. By GC, GC/MS, and cluster analysis, we identified seven chemotypes for the leaf oils. The main components found in chemotype I were safrole (1) and 3,4-(methylenedioxy)propiophenone (2). The chemotype II was dominated by 3,4-(methylenedioxy)propiophenone (2) and p-mentha-1(7),8-diene (10). The major compounds identified in chemotype III were 3,4-(methylenedioxy)propiophenone (2), myristicin (3), (E)-beta-ocimene (11), and gamma-terpinene (12). In the chemotype IV, the principal constituents were beta-caryophyllene (13), alpha-copaene (14), and 3,4-(methylenedioxy)propiophenone (2). The chemotype V was dominated by (E)-isoosmorhizole (6), (E)-anethole (8), and isoosmorhizole (7). The main compounds found in the chemotype VI were 2-methoxy-4,5-(methylenedioxy)propiophenone (4), methoxy-4,5-(methylenedioxy)propiophenone isomer 5, and (E)-isoosmorhizole (6). The major constituents in chemotype VII were beta-caryophyllene (13), bicyclogermacrene (15), and (E)-asarone (9).

Essential oils from Hyptis crenata growing wild in the Amazon Region were submitted to hydrodistillation and analysed by GC-MS. The main compounds identified in the oil of specimen A, collected at Porto Nacional, State of Tocantins, were terpinolene (37.8%) andˇ-caryophyllene (9.9%). The major components found in the oils of specimens B, collected at São Sebastião da Boa Vista, State of Pará, were 1,8-cineole (23.9%), borneol (21.8%) andˇ-caryophyllene (18.8%). The oils of specimens C and D, collected at Melgaço, Marajó Island, State of Pará, were dominated by˛-pinene (51.1%; 14.5%), 1,8-cineole (16.5%; 36.7%), limonene (15.0%;) andˇ-pinene (10.3%; 7.9%), respectively.