Correlation between caffeine and coprostanol in contrasting Amazonian water bodies.

The evaluation of contamination by domestic sewage is relevant in the Amazon region; however, it has neither been well-developed nor accompanied by research or monitoring programs. In this study, caffeine and coprostanol as indicators of sewage were investigated in water samples from Amazonian water bodies that crisscross the city of Manaus (Amazonas state, Brazil) and cover regions with distinct main land uses such as high-density residential, low-density residential, commercial, industrial, and environmental protection areas. Thirty-one water samples were studied based on their dissolved and particulate organic matter (DOM and POM) fractions. Quantitative determination of both caffeine and coprostanol was carried out using LC-MS/MS with APCI in the positive ionization mode. The streams of the urban area of Manaus had the highest concentrations of caffeine (1.47-69.65 µg L-1) and coprostanol (2.88-46.92 µg L-1). Samples from the peri-urban Tarumã-Açu stream and from the streams in the Adolpho Ducke Forest Reserve showed much lower concentrations of caffeine (20.20-165.78 ng L-1) and coprostanol (31.49-120.44 ng L-1). Samples from the Negro River showed a wider range of concentrations of caffeine (20.59-873.59 ng L-1) and coprostanol (31.72-706.46 ng L-1), with the highest values found in the outfalls of the urban streams. Levels of caffeine and coprostanol were significantly positively correlated in the different organic matter fractions. The coprostanol/(coprostanol + cholestanol) ratio proved to be a more suitable parameter than the coprostanol/cholesterol one in low-density residential areas. Proximity to densely populated areas and the flow of water bodies appear to influence the caffeine and coprostanol concentrations, which was observed in their clustering in the multivariate analysis. The results indicate that caffeine and coprostanol can be detected even in water bodies that receive very low domestic sewage input. Therefore, this study revealed that both caffeine in DOM and coprostanol in POM represent viable alternatives for use in studies and monitoring programs even in remote areas of the Amazon, where microbiological analyses are often unfeasible.

Benzylated Dihydroflavones and Isoquinoline-Derived Alkaloids from the Bark of Diclinanona calycina (Annonaceae) and Their Cytotoxicities.

Diclinanona calycina R. E. Fries popularly known as "envira", is a species of the Annonaceae family endemic to Brazil. In our ongoing search for bioactive compounds from Annonaceae Amazon plants, the bark of D. calycina was investigated by classical chromatography techniques that yielded thirteen compounds (alkaloids and flavonoids) described for the first time in D. calycina as well as in the genus Diclinanona. The structure of these isolated compounds were established by extensive analysis using 1D/2D-NMR spectroscopy in combination with MS. The isolated alkaloids were identified as belonging to the subclasses: simple isoquinoline, thalifoline (1); aporphine, anonaine (2); oxoaporphine, liriodenine (3); benzyltetrahydroisoquinolines, (S)-(+)-reticuline (4); dehydro-oxonorreticuline (3,4-dihydro-7-hydroxy-6-methoxy-1-isoquinolinyl)(3-hydroxy-4-methoxyphenyl)-methanone) (5); (+)-1S,2R-reticuline Nß-oxide (6); and (+)-1S,2S-reticuline Nα-oxide (7); tetrahydroprotoberberine, coreximine (8); and pavine, bisnorargemonine (9). While the flavonoids belong to the benzylated dihydroflavones, isochamanetin (10), dichamanetin (11), and a mixture of uvarinol (12) and isouvarinol (13). Compound 5 is described for the first time in the literature as a natural product. The cytotoxic activity of the main isolated compounds was evaluated against cancer and non-cancerous cell lines. Among the tested compounds, the most promising results were found for the benzylated dihydroflavones dichamanetin (10), and the mixture of uvarinol (12) and isouvarinol (13), which presented moderate cytotoxic activity against the tested cancer cell lines (<20.0 µg·mL-1) and low cytotoxicity against the non-cancerous cell line MRC-5 (>25.0 µg·mL-1). Dichamanetin (11) showed cytotoxic activity against HL-60 and HCT116 with IC50 values of 15.78 µg·mL-1 (33.70 µmol·L-1) and 18.99 µg·mL-1 (40.56 µmol·L-1), respectively while the mixture of uvarinol (12) and isouvarinol (13) demonstrated cytotoxic activity against HL-60, with an IC50 value of 9.74 µg·mL-1, and HCT116, with an IC50 value of 17.31 µg·mL-1. These cytotoxic activities can be attributed to the presence of one or more hydroxybenzyl groups present in these molecules as well as the position in which these groups are linked. The cytotoxic activities of reticuline, anonaine and liriodenine have been previously established, with liriodenine being the most potent compound.

Sewage contamination of Amazon streams crossing Manaus (Brazil) by sterol biomarkers.

Sewage pollution is a principal factor of decreasing water quality, although it has not been considered a real impact in Amazonia that is still considered a pristine environment around the world. Thus, this study aimed to assess the levels of sewage contamination in sediments from three streams crossing Manaus - a Brazilian city of 2,403,796 inhabitants in the heart of the Amazon rain forest. Cholesterol, cholestanol, brassicasterol, ergosterol, stigmasterol, ß-sitosterol, campesterol, stigmastanol, coprostanol, and epicoprostanol levels were determined by liquid chromatography tandem mass spectrometry (LC-MS/MS). The fecal indicator, coprostanol, was found in high concentrations (509-12 830 ng g-1) and high relative proportions (21-54%) in all samples collected in the Mindu stream that crosses many heavily populated districts of the city, and in the Quarenta stream that crosses the Industrial District of Manaus. The sediments of the Tarumã-Açu stream also presented coprostanol; however, concentrations (

Caracterização físico-química das misturas binárias de biodiesel e diesel comercializados no Amazonas / Physical chemical characterization of binary mixtures of biodiesel and diesel commercialized in Amazonas

O uso de energias renováveis aliadas à preservação do meio ambiente tem despertado interesse cada vez maior em nível nacional e internacional principalmente a utilização do biodiesel em substituição ao diesel de petróleo. Sua utilização traz uma série de vantagens sociais, econômicas e ambientais. Nos últimos anos, houve no Brasil um aumento nas pesquisas sobre o biodiesel. A lei brasileira nº 11.097 de 2005 dispõe sobre a introdução do biodiesel na matriz energética brasileira, misturado ao óleo diesel em um percentual mínimo obrigatório de 2 por cento, com aumento na adição para 5 por cento até 2012. Contudo, essa adição só é possível se o biodiesel estiver dentro dos padrões de qualidade exigidos. Diante disto, neste trabalho foram preparadas misturas de biodiesel adicionado ao diesel interior, nas proporções 2, 5, 10 e 20 por cento (v/v), sendo posteriormente caracterizados a partir da determinação dos parâmetros físico-químicos citados na Resolução da Agência Nacional do Petróleo, Gás Natural e Biocombustíveis (ANP), visando avaliar se as misturas estão em conformidade com a norma. De acordo com os resultados concluiu-se que, tanto o biodiesel quanto suas misturas binárias (B2 a B20) encontram-se dentro dos padrões de qualidade estabelecido pela ANP.

The use of renewable energies allied to the preservation of the environment has awakening more and more interest on the national and international level, especially the utilization of biodiesel in substitution of petroleum diesel. Its use brings a series of social, economical and environmental advantages. In the last few years, there has been an increase in biodiesel research in Brazil. The Brasilian law no. 11.097 of 2005 proposes the introduction of biodiesel in the Brazilian energetic matrix, mixing it with diesel oil at an obligatory percentile minimum of 2 percent, with an increase of 5 percent in the addition, until 2012. However, the addition is only permitted if the biodiesel is within the quality patterns demanded. Before this, mixtures of biodiesel added to interior diesel were prepared, in proportions of 2, 5, 10 and 20 percent (v/v), which were later characterized, as of the physical chemical parameters determined in the Agência Nacional do Petróleo, Gás Natural e Biocombustíveis (ANP) Resolution for evaluating mixtures in accordance with the norm. The results show that, biodiesel as well as their binary mixtures (B2 to B20) are within the quality patterns established by the ANP.

Cytotoxic evaluation of essential oil from Casearia sylvestris Sw on human cancer cells and erythrocytes / Avaliação citotóxica do óleo essencial de Casearia sylvestris Sw sobre células tumorais humanas e eritrócitos

Casearia sylvestris (Flacourtiaceae) is a plant popularly known as "guaçatonga" and it is used by indigenous population from South America (Brazil, Peru and Bolivia) in the treatment of several diseases, including cancer. Cytotoxic studies showed that it presents an interesting antitumoral potential due to the presence of casearins and the essential oil showed a high percentage of potent cytotoxic sesquiterpenes (β-caryophyllene and α-humulene). In this work, we verified that the essential oil of C. sylvestris presents a good selective cytotoxicity against HeLa, A-549 and HT-29 tumor cells (CD50 63.3, 60.7 and 90.6 µg.ml-1, respectively) when compared to non-tumoral cells Vero (CD50 210.1 µg.ml-1) and mice macrophages (CD50 234.0 µg.ml-1). The oil causes hemolysis in seven different kinds of erythrocytes, indicating that C. sylvestris must be used carefully. Besides, standard of β-caryophyllene and α-humulene were also tested and they showed similar cytotoxicity to the cytotoxicity presented in the oil, indicating that they might be responsible for the toxic effects that were observed in this study.

A Casearia sylvestris (Flacourtiaceae) é uma planta popularmente conhecida como "guaçatonga" e é usada por povos indígenas da América do sul (Brasil, Peru e Bolivia) no tratamento de muitas doenças, incluindo câncer. Estudos citotóxicos mostraram que esta planta apresenta um possível e interessante potencial antitumoral devido à presença de moléculas chamadas casearinas. Além disso, a composição do óleo essencial mostrou uma alta concentração de sesquiterpenos de alto potencial citotóxico. Neste trabalho, nós verificamos que o óleo essencial da C. sylvestris apresentou uma boa citotoxicidade seletiva contra as linhagens de células tumorais HeLa, A-549 and HT-29 (CD50 63,3, 60,7 e 90,6 µg.ml-1, respectivamente) quando comparada às células não-tumorais Vero (CD50 210,1 µg.ml-1) e macrófagos de camundongos (CD50 234,0 µg.ml-1). Além disso, o óleo causou hemólise em sete diferentes tipos de eritrócitos, indicando que a C. sylvestris precisa ser usada com cuidado. Também foram testados padrões de β-cariofileno e α-humuleno que mostraram citotoxicidade similar àquelas apresentadas pelo óleo, indicando que estes compostos podem ser os responsáveis pelos efeitos tóxicos que foram observados neste estudo.