219 research outputs found

    Professor Marcos Eberlin, who is the chief executive of the Brazilian Society of Mass Spectrometry, recently spoke to BrJAC about his work

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    Quantification of Sterol and Triterpenol Biomarkers in Sediments of the Cananéia-Iguape Estuarine-Lagoonal System (Brazil) by UHPLC-MS/MS

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    Sterols and triterpenols present in sedimentary cores from 12 stations along the Cananéia-Iguape estuarine-lagoonal system were investigated by ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Ten sterols and three triterpenols were identified and quantified, indicating both natural and anthropogenic sources. The relative distributions of sterol and triterpenol showed that the study area is submitted to organic matter (OM) from the Ribeira de Iguape River, seawater, surrounding vegetation, and plankton production. The contribution of these sources depends on the region of the estuarine-lagoonal system and the depth of sediment. Regarding anthropogenic sources, only the samples submitted to freshwater flow from the Ribeira de Iguape River presented concentration of coprostanol higher than the threshold value and diagnostic ratios, coprostanol/(coprostanol + cholestanol) and coprostanol/cholesterol, that indicate moderate contamination by domestic sewage in that area of the estuarine-lagoonal system. Therefore, the approach used herein identified the OM sources and its transport along the Cananéia-Iguape estuarine-lagoonal system (Brazil), which is a complex of lagoonal channels located in a United Nations Educational, Scientific and Cultural Organization (UNESCO) Biosphere Reserve

    Vaginal lipidomics of women with vulvovaginal candidiasis and cytolytic vaginosis: a non-targeted LC-MS pilot study

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    sem informaçãoTo characterize the lipid profile in vaginal discharge of women with vulvovaginal candidiasis, cytolytic vaginosis, or no vaginal infection or dysbiosis. Design. Cross-sectional study. Setting. Genital Infections Ambulatory, Department of Tocogynecology,138sem informaçãosem informaçãosem informaçãoThe supervision of the laboratory studies by Gustavo Henrique Bueno Duarte at Thomson Mass Spectrometry Laboratory–Campinas State Universit

    LC-MS characterization of valsartan degradation products and comparison with LC-PDA

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    Valsartan was submitted to forced degradation under acid hydrolysis condition as prescribed by the ICH. Degraded sample aliquots were separated via HPLC using a Hypersil ODS (C18) column (250 x 4.6 mm i.d., 5 µm). Either photodiode array (PDA) detection or mass spectrometry (MS) full scan monitoring of HPLC runs were used. HPLC-PDA failed to indicate Valsartan degradation under forced acid degradation, showing an insignificant peak area variation and that Valsartan apparently remained pure. HPLC-MS using electrospray ionization (ESI) and total ionic current (TIC) monitoring did not reveal any peak variation either, but inspection of the ESI mass spectra showed the appearance of m/z 306 and m/z 352 ions for the same retention time as that of Valsartan (m/z 436). These ions were identified as being protonated molecules of two co-eluting degradation products formed by hydrolysis. These assignments were confirmed by ESI-MS/MS with direct infusion of the degraded samples. The results showed that the use of selective HPLC-MS is essential for monitoring Valsartan degradation. Efficient HPLC separation coupled to selective and structural diagnostic MS monitoring seems therefore mandatory for comprehensive drug degradation studies, particularly for new drugs and formulations, and for method development.Valsartana (VAL) foi submetida à degradação forçada em meio ácido conforme procedimento descrito no ICH. Os produtos de degradação (PDs) foram monitorados ao longo do tempo de degradação pela técnica de Cromatografia Líquida (LC) utilizando uma coluna Hypersil ODS (C18) (250 x 4,6 mm d.i., 5 µm). A detecção foi feita com dois detectores: espectrofotométrico (PDA) e espectrometria de massas (MS) por corrente iônica total. Ambas as técnicas falharam na identificação dos PDs obtidos ao longo do monitoramento, mostrando insignificantes variações na área do pico e permanecendo com pureza de pico ao longo de toda a eluição. Somente depois da avaliação por íon extraído (XIC), foi possível observar o aumento do íon m/z 306 e m/z 352 exatamente no mesmo tempo de retenção do íon molecular (m/z 436). Estes resultados mostram um caso simples e didático em que somente o uso de um método seletivo de LC-MS pode ser utilizado para monitorar produtos de degradação. Neste trabalho, é apresentado um caso real em que a separação por LC deve ser acoplada a métodos seletivos obtidos por MS, especialmente no estudo de PDs para novos fármacos, formulações e no desenvolvimento de métodos

    Production and characterization of surface-active compounds from gordonia amicalis

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    Two methods were used to make crude preparations of surface-active compounds (SACs) produced by Gordonia amicalis grown on the medium containing 1% diesel oil. Using a 2:1 (v/v) solution of chloroform:methanol for extraction, Type I SACs were isolated and shown to produce oil in water (O/W) emulsions. Type II SACs were isolated by precipitation with ammonium sulfate and produced predominantly water in oil emulsions (W/O). The crude Type I and II preparations were able to produce a significant reduction in the surface tension of water; however, the crude Type II preparation had 10-25 fold higher emulsification activity than the Type I preparation. Both SAC preparations were analyzed by the TLC and each produced two distinct bands with Rf 0.44 and 0.62 and Rf 0.52 and 0.62, respectively. The partially purified SACs were characterized by the ESI(+)-MS, FT-IR and NMR. In each one of these fractions, a mixture of 10 oligomers was found consisting of a series of compounds, with masses from 502 to 899, differing in molecular mass by a repeating unit of 44 Daltons. The mass spectra of these compounds did not appear to match other known biosurfactants and could represent a novel class of these compounds.Two methods were used to make crude preparations of surface-active compounds (SACs) produced by Gordonia amicalis grown on the medium containing 1% diesel oil. Using a 2:1 (v/v) solution of chloroform:methanol for extraction, Type I SACs were isolated and551138144Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    Espectrometria De Massas Por Introdução Via Fibra

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    Método que proporciona análise de amostras cerca de dez vezes mais rápida, maior variedade na análise de compostos químicos, às vezes apresenta limites de detecção superiores aos de SPME-CG/MS e simplicidade na confecção da sonda para SPME. Constituído por um guia que é introduzido no espectrômetro de massas e fixado de modo que um septo sirva de interface ambiente/vácuo. Após a fibra adsorver seletivamente os compostos em água ou "headspace", ela é retraída para dentro da agulha, inserida através do septo e depois exposta entre os filamentos. Os compostos a serem analisados são desorvidos da fibra através do aquecimento do filamento, ionizados por elétrons e analisados diretamente pelo espectrômetro de massas através de suas razões m/z. Os analitos que estão sorvidos na fibra se desorvem em cerca de um minuto.BR0200365H01J49/04H01J49/04BR20020200365H01J49/04H01J49/0

    Phytochemical analysis and antifungal activity of extracts from leaves and fruit residues of brazilian savanna plants aiming its use as safe fungicides

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The increasing demand for safe food without preservatives or pesticides residues has encouraged several studies on natural products with antifungal activity and low toxicity. In this study, ethanolic extracts from leaves and fruit residues (peel and seeds) of three Brazilian savanna species (Acrocomia aculeata, Campomanesia adamantium and Caryocar brasiliense) were evaluated against phytopathogenic fungi. Additionally, the most active extract was chemically characterized by ESI-MS and its oral acute toxicity was evaluated. Extracts from C. brasiliense (pequi) peel and leaves were active against Alternaria alternata, Alternaria solani and Venturia pirina with minimal inhibitory concentrations between 350 and 1000 mu g/mL. When incorporated in solid media, these extracts extended the lag phase of A. alternata and A. solani and reduced the growth rate of A. solani. Pequi peel extract showed better antifungal activity and their ESI-MS analysis revealed the presence of substances widely reported as antifungal such as gallic acid, quinic acid, ellagic acid, glucogalin and corilagin. The oral acute toxicity was relatively low, being considered safe for use as a potential natural fungicide. [GRAPHICS] .The increasing demand for safe food without preservatives or pesticides residues has encouraged several studies on natural products with antifungal activity and low toxicity. In this study, ethanolic extracts from leaves and fruit residues (peel and seeds6195204FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)2011/19057-7; 2012/21395-0We are grateful to São Paulo Research Foundation for the financial support of this research and for the fellowships awarded to C.A.B. (FAPESP No. 2011/19057-7) and G.A.B. (FAPESP No. 2012/21395-0) and to Study Group of Cerrado Agro-industrial Processes (

    Anticholinesterase activity evaluation of alkaloids and coumarin from stems of Conchocarpus fontanesianus

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    Conchocarpus fontanesianus (A. St.-Hill.) Kallunki & Pirani, Rutaceae, popularly known as pitaguará, is a native and endemic tree from São Paulo and Rio de Janeiro States, Brazil. Based in the information that anticholinesterasic derivatives could act as new prototypes to treatment of Alzheimer disease, this work describes the fractionation guided by evaluation of the anticholinesterase activity of the ethanolic stems extract from C. fontanesianus. This procedure afforded the alkaloids dictamnine (1), γ-fagarine (2), skimianine (3), and 2-phenyl-1-methyl-4-quinolone (4), as well as the coumarin marmesin (5).Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Instituto de Botânica de São Paulo Núcleo de Pesquisa em Fisiologia e BioquímicaInstituto de Botânica de São Paulo Núcleo de Pesquisa Curadoria do Herbário São PauloUniversidade Estadual de Campinas Centro Pluridisciplinar de Pesquisas Químicas, Biológicas e AgrícolasUniversidade Estadual de Campinas Laboratório Thomson Espectrometria de MassaUniversidade Federal de São Paulo (UNIFESP) Departamento de Ciências Exatas e da TerraUniversidade de São Paulo Instituto de QuímicaUNIFESP, Depto. de Ciências Exatas e da TerraSciEL

    Search for alkaloids on callus culture of Passiflora alata

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    Preliminary work on Passiflora alata leaves failed to detect harmane alkaloids using LC. The aim of this work was to investigate the production of harmane alkaloids through the cell culture of P. alata, inducing its precursor (L-tryptophan). The leaf explants presented satisfactory results after disinfection, and the callus formation was initiated in MS media with adequate quantities of phytohormones. Sixty days after inoculation, calli were inoculated in the optimized semi-solid MS media, with and without the addition of L-tryptophan (50, 100, 200 mg/L) and kept in standard conditions for 90 days. Calli were collected on days 6, 16, 26, 36, and 90, followed by acid-base extraction, and analysed by LC. The results showed an absence of harmane, harmin, harmol, harmalol, and harmaline. With L-tryptophan feeding, two peaks were detected, collected and analysed through positive mode electrospray [ESI(+)-MS] and sequential analysis in tandem ESI(+)-MS/MS. The spectra obtained were very similar, with a repetition of the more intense ions, and consecutive loss of 68 Da units, attributed to the heterocycle pyrazole. It appeared that this transformation was not related to any enzymatic pathway previously described for the plant from L-tryptophan, and the biosynthesis of β-carboline alkaloids in callus culture of P. alata were not observed in this work.As folhas de varias espécies de Passiflora são utilizadas como ansioliticas e sedativas. Passiflora alata Curtis, Passifloraceae consta em três edições da farmacopéia brasileira, porem não há muitos estudos sobre sua composição química. No passado, enfatizava-se a ação conjunta de alcalóides e flavonóides. Em trabalho anterior, não foi detectada a presença de alcalóides harmanicos através de CLAE. Assim, decidiu-se investigar a produção dos mesmos através de cultivo celular, introduzindo seu precursor metabólico L-triptofano. Os explantes foliares apresentaram resultados satisfatorios para germinação apos assepsia, e a formação de calo foi iniciada em meio MS com quantidades adequadas de fitohormonios, previamente determinadas. Sessenta dias após a inoculação os calos foram repicados para meio semi-solido com e sem L-triptofano (50, 100, 200 mg/L), mantidos por 90 dias em condições padrão. Amostras foram coletadas com 6, 16, 26, 36, e 90 dias, realizada extração acido-base e o extrato analisado por CLAE. Os resultados mostraram a ausência de harmana, harmina, harmol, harmalol e harmalina. Dois picos presentes nas amostras com L-triptofano foram coletados e analisados através de espectrometria de massas, electrospray modo positiva [ESI(+)-MS] e analise em tandem ESI(+)-MS/MS. Os espectros correspondentes foram similares, mostrando a perda consecutiva de 68 Da, atribuídos ao pirazol. Este fato aponta para uma transformação não enzimática, não relacionada a uma biossintese previamente descrita para alcalóides β-carbolínicos.90191

    Cyclam ''capa' POT.4' to ''capa' POT.3' denticity change upon mono-N-substitution with a carboxypropyl pendant arm in a ruthenium nitrosyl complex

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    The complex fac-[Ru(NO)Cl2(kappa(3)N(4),N(8),N(11)(1-carboxypropyl)cyclam)]Cl.H2O (1-carboxypropyl)cyclam=3-(1,4,8,11-tetraazacyclotetradecan-1-yl)propionic acid) was prepared in a one pot reaction by mixing equimolar amounts of RuNOCl 3 and (1-carboxypropyl)cyclam and was characterized by X-ray crystallography, electrospray ionization tandem mass spectrometry (ESI-MS/MS), elemental analysis, NMR, and electronic and vibrational (IR) spectroscopies. fac-[Ru(NO)Cl 2(kappa(3)N(4),N(8),N(11)(1-carboxypropyl)cyclam)]Cl.H2O crystallizes in the triclinic, space group P1, No. 2, with unit cell parameters of a=8.501(1) A, b=9.157(1) A, c=14.200(1) A, alpha=72.564(5) degrees , beta=82.512(5) degrees , gamma=80.308(5) degrees , and Z=2. The Ru-N interatomic distance and bond angle in the [Ru-NO] unit are 1.739(2) A and 167.7(2) degrees , respectively. ESI-MS/MS shows characteristic dissociation chemistry that initiates by HCl or NO loss. The IR spectrum displays a nu(NO) at 1881 cm(-1) indicating a nitrosonium character. The electronic spectrum shows absorptions bands at 264 nm (log epsilon=3.27), 404 nm (log epsilon=2.53), and 532 nm (log epsilon=1.88). (1)H and (13)C NMR are in agreement with the proposed molecular structure, which shows a very singular architecture where the cyclam ring N (with the carboxypropyl pendant arm) is not coordinated to the ruthenium resulting in a kappa(3) instead of the expected kappa(4) denticity.FAPESPCNPqCAPE
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