Browsing by Author "Werle, Alceni Augusta"

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    Biflavonoids and a glucopyranoside derivative from Ouratea semiserrata.
    (2002) Velandia, Javier Rincon; Carvalho, Mário Geraldo de; Braz Filho, Raimundo; Werle, Alceni Augusta
    Two new biflavonoids, 5-hydroxy-7-methoxyflavone-(4 →O→8 )-4 ,5 ,7 -trihydroxyflavone and 5-hydroxy- 7-methoxyflavone-(4 →O→8 )-5 ,7 -dihydroxy-4 -methoxyflavone, and the glucopyranoside derivative, 1-O-(4-hydroxyphenyl)-6-O-(4-hydroxybenzoyl)- -D-glucopyranoside, as well as the known biflavones lanaraflavone, amentoflavone and podocarpusflavone, the triterpenes lupeol and friedelin, the lignans eudesmin and epieudesmin, the flavonol glycoside rutin, the steroids -sitosterol, stigmasterol, 3 - O- -D-glucopyranosylsitosterol, 7-oxostigmast-5-en-3 -ol and 7-oxostigmasta-5,22-dien-3 -ol, the carbohydrates - and -glucopyranose and 1-O-(4-hydroxybenzoyl)- -D-glucopyranoside, and the norsesquiterpene 6,9-dihydroxymegastigma-4,7-dien-3-one, have been isolated from leaves and branches of Ouratea semiserrata. The structures of these compounds were established from spectral data, including twodimensional NMR experiments and mass spectra.
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    Chemical constituents from Luxemburgia nobilis (EICHL).
    (2000) Carvalho, Mário Geraldo de; Oliveira, Marcia Cristina Campos de; Werle, Alceni Augusta
    O fracionamento cromatográfico do extrato hexânico dos galhos de Luxemburgia nobilis (Ochnaceae) forneceu sitosterol, estigmasterol, ácido betulínico, os ácidos graxos hexadecanóico, tetraeicosanóico, hexaeicosanóico e linoleico, 14-metilpentadecanoato de metila, óxido de 13- epimanoíla, o depsídeo atranorina (1), e dois triglicerídeos novos (2 e 3). As estruturas das substâncias isoladas foram determinadas através da análise dos dados espectroscópicos de I.V., massas e RMN de 1H e de 13C incluindo comparação com dados da literatura. A análise do espectro de massas (FAB-MS) dos éteres tiometílicos (4 e 5) foi usada para definir as estruturas dos triglicerídeos.
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    Degradation of cimetidine by oxidative processes, mass spectrometry products elucidation and toxicity evaluation.
    (2020) Quaresma, Amanda de Vasconcelos; Sousa, Bianca Aline de; Rúbio, Karina Taciana Santos; Silva, Silvana de Queiroz; Werle, Alceni Augusta; Afonso, Robson José de Cássia Franco
    The use of pharmaceuticals has gradually increased and they have become a concern due to the ecological potential impact. Cimetidine (CIM), employed in the treatment of gastrointestinal disorders, is detected frequently in waters worldwide. In this study, CIM aqueous solutions were exposed to four oxidative processes: chlorination (NaClO), ozonation (O3), photocatalysis (UV/TiO2) and photolysis (UV). Low removal of organic matter was observed by total organic carbon measurement. CIM removal was determined by mass spectrometry. CIM was completely degraded in the chlorination and ozonation experiments but not by photodegradation. The results indicate that CIM removal occurs by transformation into persistent degradation products. Seven products, among them five have until now not been reported, were elucidated throughout the experiments by high resolution mass spectrometry and the CIM degradation reaction pathways were proposed. The degradation products were mainly formed by the oxidation of thioether, addition of hydroxyl radicals and oxidative cleavage. No difference in MTT cytotoxicity against HepG2 cells between the treated and untreated CIM solutions was observed. For solutions treated by photolysis, a trend of decreased cell viability with increasing concentration was observed. The ECOSAR software was used to estimate the toxicity of degradation products by structureactivity relationship. Among the identified products only one (CIM-97 - C5H8N2) was considered harmful for the organisms evaluated. The toxicity may be attributed to the presence of the imidazole group, present in molecules of biological importance and used in pharmaceutical industry.
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    Luxenchalcone, a new bichalcone and other constituents from Luxemburgia octandra.
    (2004) Carvalho, Mário Geraldo de; Alves, Cássia Cristina Fernandes; Silva, Kedma Grazielle Souza da; Eberlin, Marcos Nogueira; Werle, Alceni Augusta
    O fracionamento cromatográfico dos extratos de folhas e galhos de Luxemburgia octandra (Ochnaceae) resultou no isolamento de: isoliquiritigenina, 3’-hidroxiisoliquiritigenina, b-sitosterol, estigmasterol, lupeol, ácido betulínico, o biflavonóide, 4’,5,7-triidroxiflavona-(3’O4’”)-5”,7”- diidroxiflavanona e uma nova bichalcona, 4,2’,4’-triidroxichalcona-(3O4”)-2’”,4’”- diidroxichalcona (luxenchalcona). As estruturas desses compostos foram estabelecidas com base na análise dos dados espectrométricos de IV, EM e RMN incluindo experimentos 2D das substâncias naturais e do derivado metilado da luxenchalcona.
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    Metabólitos especiais isolados de Laseguea erecta (Apocynaceae).
    (2006) Carvalho, Mário Geraldo de; Alves, Cássia Cristina Fernandes; Werle, Alceni Augusta; Braz Filho, Raimundo
    Do caule de Laseguea erecta foram isolados o lupeol, a cumarina escopoletina, o lignóide pinoresinol e o glicosil-cardenoídeo, 􀁄-L-tevetosil-digitoxigenina. As estruturas foram identifi cadas com o uso de técnicas espectroscópicas de IV, RMN 1H e 13C, incluindo técnicas especiais 1D e 2D, espectroscopia de massas e comparação com dados da literatura.
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    New biflavonoid and other constituents from luxemburgia nobilis (EICHL).
    (2002) Oliveira, Marcia Cristina Campos de; Carvalho, Mário Geraldo de; Silva, Cleber José da; Werle, Alceni Augusta
    O fracionamento cromatográfico dos extratos orgânicos das folhas e galhos de Luxemburgia nobilis (Ochnaceae) forneceu o sitosterol, sitosterol-3-O- βD-glicopiranosil, friedelina, friedelinol, a mistura dos triterpenos lupeol, α-amirina e β -amirina, rutina, epicatequina, uma mistura de duas chalconas, isoliquiritigenina e 3’-hidróxiisoliquiritigenina, duas biflavonas conhecidas, amentoflavona e robustaflavona além de uma biflavona nova, 5,7,4’-triidróxiflavona-(3’-O-4”’)-5”,7”-diidróxiflavanona. As estruturas foram definidas através dos dados espectrométricos incluindo experimentos bidimensionais de RMN das substâncias naturais e dos derivados metilados e acetilados da biflavona nova.
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    Oxidative treatments for atenolol removal in water : elucidation by mass spectrometry and toxicity evaluation of degradation products.
    (2019) Quaresma, Amanda de Vasconcelos; Sousa, Bianca Aline de; Rúbio, Karina Taciana Santos; Silva, Silvana de Queiroz; Werle, Alceni Augusta; Afonso, Robson José de Cássia Franco
    Rationale The presence of pharmaceuticals in water is a worldwide concern due to potential damage to human and environmental health. For example, compounds such as the β‐blocker atenolol (ATE), widely used for the treatment of cardiac disease, are detected in drinking water since conventional water treatment plants are not designed to remove them. Thus, the evaluation of ATE removal at different water oxidative treatment processes, identification of its degradation products and evaluation of their toxicity is necessary. Methods Aqueous solutions of ATE (10 mg/L) were submitted to oxidative treatments of chlorination ([NaClO] = 10 mg/L), ozonation ([O3] = 8 mg/L), photocatalysis ([TiO2] = 120 mg/L and UV‐C light) and photolysis (UV‐C light). The removal of ATE and formation of degradation products (DPs) were monitored by mass spectrometry. To assess acute cytotoxicity, DPs were submitted to colorimetric MTT assay using HepG2 cells. The Ecological Structure Activity Relationships (ECOSAR) software was applied to estimate the acute and chronic toxicity of identified DPs at different trophic levels. Results Photocatalysis was the treatment that demonstrated greater efficiency, removing 94% of the initial ATE. For the four tested treatments, 12 DPs were confirmed after 30 min. Moreover, some of the identified DPs were unpublished in the literature. Through high‐resolution mass spectrometry (HRMS), it was possible to elucidate the structure of the DPs. Solutions of DPs were not considered to be toxic to HepG2 cells. Only the DP with a molecular formula of C13H19NO3 (m/z 238.1438) could be considered detrimental to daphnid and green algae. Conclusions Low rates of organic matter removal and high rates of ATE degradation were obtained in the applied treatments after 30 min. Although the treated solutions were not toxic to HepG2 cells, one of the degradation products can be considered an environmental concern since it presents chronic toxicity to daphnid and green algae.
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    Proposed active constituents of Dipladenia martiana.
    (2001) Carvalho, Mário Geraldo de; Cranchi, Daniela Carvalho; Kingston, David G. I.; Werle, Alceni Augusta
    3 -O- -D-glucopyranosylsitosterol, pomolic acid, ursolic acid, epicatechin, kaempferol, kaempferol-3-O- -D-glucopyranoside (astragalin), quercetin-7-O- -D-glucopyranoside, quercetin-7-O- -D-galactopyranoside and quebrachitol were isolated by chromatographic fractionation of the methanol extract from the aerial parts of Dipladenia martiana (Apocynaceae). The hexane extract yielded lupeol and sitostenone. These compounds are likely to be responsible for the therapeutic effects.
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    Removal of dexamethasone by oxidative processes : structural characterization of degradation products and estimation of the toxicity.
    (2021) Quaresma, Amanda de Vasconcelos; Rúbio, Karina Taciana Santos; Taylor, Jason Guy; Sousa, Bianca Aline de; Silva, Silvana de Queiroz; Werle, Alceni Augusta; Afonso, Robson José de Cássia Franco
    Dexamethasone (DEX) belongs to a class of steroid hormones that can potentially be harmful due to their endocrine disrupting properties. The efficient elimination of DEX during the treatment of drinking water is needed to ensure that the health of both human and aquatic species are protected. Thus different oxidative processes were investigated in order to assess the effect of these procedures and conditions on DEX. Aqueous solutions of DEX were treated by conventional chlorination ([NaClO]=10 mg L− 1 ) and advanced oxidative processes (ozonation – [O3]=8 mg L− 1 ; photocatalysis – [TiO2]=120 mg L− 1 and UV-C; photolysis – UV-C). The most and least efficient processes for DEX removal were ozonation (95%) and chlorination (54%), respectively. In total, 16 degradation products were identified and characterized by high-resolution mass spectrometry and only two have been proposed in previous reports. Chemical structures of the degradation products were proposed and alcohol oxidation, ozonolysis and decarboxylation were the main chemical transformations observed. The toxicities of DEX and its derivatives were evaluated by following methods: MTT assay (HepG2 cell), ECOSAR (acute and chronic toxicity) and molecular docking (AutoDock). MTT assay results demonstrated that only a mixture DEX and the chlorinated derivative were toxic at high concentrations. ECOSAR analysis showed that products formed from dehydration and fluoride elimination were more toxic than intact DEX, mainly for fish and Daphnid and to a lesser extent for green algae. The docking study revealed that these degradation products were not capable of making hydrogen bonds with residual amino acids GLN570, GLN642 and CYS736, but were stable at the glucocorticoid receptor indicating the possibility of being toxic to humans.
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    The complete assignment of 1H- and 13C-NMR of prenylated xanthones from Tovomita spp. (Guttiferae).
    (1997) Nagem, Tanus Jorge; Werle, Alceni Augusta; Carvalho, Mário Geraldo de; Mesquita, Antônio Augusto Lins
    A 1,6-dihidroxy-5-(3-metilbut-2-enil)-6’,6’-dimetil-pirano(2’,3’;7,8)- 6”,6”- dimetilpirano (2”,3”;3,2)xantona e a 1,3,6-trihidroxi-6’,6’-dimetil-pirano(2’,3’;7,8)-2,5- di-(3-metilbut-2-enil)xantona tiveram seus deslocamentos químicos de hidrogênio e carbono-13 atribuídos de forma inequívoca, com base nas informações obtidas através dos espectros de RMN de 1H[1D e 2D(1H-1H-COSY) e de correlação heteronuclear 1H-13C-COSY[nJCH(n = 1, 2 e 3)]. Estes da dos ainda foram confirmados utilizando-se a técnica de NOE diferencial. The 1H-and 13C-NMR spec tral data of 1,6-dihydroxy-5-(3-methylbut-2- enyl)-6’,6’-dimethyl-pyrano(2’,3’;7,8)-6”,6”-dimethyl-pyrano(2”,3”;3,2)xanthone and 1,3,6-trihydroxy-6’,6’-dimethyl-pirano(2’,3’;7,8)-2,5-di-(3-methylbut-2-enyl)xanthone have been un am big u ously as signed by the anal y sis of homonuclear (1H-1H-COSY) and heteronuclear [1H-13C-COSY: mod ulated with 1JCH and nJCH (n = 2 and 3, COLOC)] shift-correlated and NOE dif ference spectra.
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    Triterpenos e flavonóides isolados de flores de Laseguea erecta (Apocynaceae).
    (2007) Carvalho, Mario Geraldo de; Cardozo, Maritza A. Rojas; Silva, Virginia Claudia da; Werle, Alceni Augusta
    Das flores de Laseguea erecta isolaram-se o lupeol, ácido ursólico e os flavonóides quercetina (3,5,7,3’,4’-pentaidroxiflavona) e 3-O-α-L-arabinopiranosil quercetina. Esta é o primeiro estudo sobre metabólitos especiais em flores desse gênero. As estruturas foram determinadas através da análise dos dados espectrais de IV, RMN de 1H e 13C (1D e 2D) e comparação com valores registrados na literatura.