O gênero Hypericum (Guttiferae = Clusiaceae) compreende 494 espécies acomodadas em 36 seções taxonômicas. Os representantes americanos pertencem, sobretudo, às seções Brathys e Trigynobrathys, as duas maiores com 87 e 52 espécies, respectivamente. Popularmente, estas plantas são utilizadas como antissépticos, diuréticos, digestivos e agentes de cicatrização. Quimicamente, apresentam tendência em acumular floroglucinóis diméricos, além de benzofenonas, benzopiranos, flavonoides e ácidos fenólicos, metabólitos cuja atividade antidepressiva, antinociceptiva, antimicrobiana, antiproliferativa e antioxidante são descritas. Considerando o potencial terapêutico, este trabalho objetivou a determinação dos principais compostos fenólicos presente nas flores de espécies Hypericum nativas do Sul do Brasil (H. campestre, H. caprifoliatum, H. carinatum, H. connatum, H. linoides, H. myrianthum, H. polyanthemum e H. salvadorense) e dos Páramos peruanos (H. andinum e H. laricifolium); a extração e análise dos compostos fenólicos de H. carinatum obtidos com CO2 supercrítico e a investigação da atividade antifúngica e antiquimiotática dos extratos lipofílicos de H. caprifoliatum, H. carinatum, H. linoides, H. myrianthum e H. polyanthemum. Para os experimentos, foram coletadas (2008 - 2010) as partes aéreas das plantas em floração. Todas as coletas foram autorizadas pelos órgãos de proteção ambiental. Os métodos extrativos incluem maceração estática, ultrassom e CO2 supercrítico (temperatura = 40, 50 ou 60ºC; pressão = 90, 120, 150 ou 200 bar). As análises por CLAE foram realizadas em coluna de fase reversa (C18), sistemas isocráticos compostos por acetonitrila, água e ácido trifluroacético e detecção ultravioleta (220, 270 ou 254 nm); Os picos foram identificados pela comparação dos tempos de retenção/co-injeção com padrões e quantificados pela curva de calibração dos compostos. Os ensaios antifúngico e antiquimiotático foram realizados pelo método de microdiluição em caldo e inibição da migração de neutrófilos, respectivamente. O floroglucinol dimérico uliginosina B (0,008 – 0,188%) e o flavonoide hiperosídeo (0,057 – 5,987%) foram os principais metabólitos detectados nas flores das espécies investigadas. Hypericum caprifoliatum e H. andinum apresentaram o maior rendimento destes compostos, respectivamente. Sete espécies apresentaram japonicina A em concentrações de 0,003 a 0,087% (H. myrianthum). O rendimento de hiperbrasilol B variou de 0,006% em H. laricifolium a 0,011% em H. caprifoliatum. Os benzopiranos (HP1 = 0,200%, HP2 = 0,225% e HP3 = 0,327%) e as benzofenonas (carifenona A = 0,309% e carifenona B = 0,062%) ocorreram exclusivamente em H. polyanthemum e H. carinatum. As máximas quantidades de ácido clorogênico, isoquercitrina, quercitrina e guaijaverina foram observadas, respectivamente, em H. campestre (1,458%), H. andinum (1,161%), H. carinatum (0,231%) e H. laricifolium (0,404%). Tais resultados fornecem suporte adicional para o significado quimiotaxonômico dos derivados diméricos de floroglucinol. Temperatura (40°C = 3,04%, 50°C = 2,21% e 60°C = 1,05%) e pressão (90 bar = 0,95%, 150 bar = 0,97% e 200 bar = 1,89%) afetaram de modo distinto o rendimento do extrato supercrítico de H. carinatum. Apesar do menor rendimento em comparação ao extrato n-hexano (6,09%), a extração com CO2 supercrítico provou ser mais seletiva que a maceração. Nas condições ideais (40°C, 90 bar e 180 minutos), a máxima recuperação de uliginosina B, carifenona A e carifenona B foi, respectivamente, 162,83, 376,33 e 48,79%. O modelo matemático empregado para simular o processo de extração foi apropriadamente correlacionado aos dados experimentais. Considerando as atividades biológicas, todas as espécies investigadas apresentaram um amplo espectro de ação antifúngica, assim como reduziram a migração dos neutrófilos. Os extratos de H. carinatum, H. linoides e H. myrianthum apresentaram os mais baixos valores de concentração inibitória mínima contra Cryptococcus neoformans (CIM £ 15,6 μg/mL), Rhodotorula mucilaginosa (CIM £ 62,5 μg/mL), Candida glabrata e C. tropicalis (CIM = 1,9-250 μg/mL). Para estas plantas, o efeito antiquimiotático variou entre 60 - 100% nas concentrações de 0,31 a 10 μg/mL. Os extratos mais ativos apresentaram elevada concentração de uliginosina B, japonicina A e hiperbrasilol B. Assim, as espécies de Hypericum nativas do sul do Brasil apresentam potencial como fonte de novos antifúngicos e anti-inflamatórios. / The genus Hypericum (Guttiferae = Clusiaceae) comprises 494 species placed in 36 taxonomic sections. The representatives of Central and South America belong primarily to sections Brathys and Trigynobrathys, the two largest sections with 87 and 52 species, respectively. In traditional medicine, these plants are used as antiseptic, diuretic, digestive and as healing agents. Such species have a strong tendency to accumulate dimeric phloroglucinol, besides benzophenones, benzopyrans, flavonoids and phenolic acids, metabolites whose antidepressant, antinociceptive, antimicrobial, antiproliferative and antioxidant activities are described. In view of the therapeutic potential, this work aimed to determine the main phenolic compounds present in flowers of Hypericum species native to southern Brazil (H. campestre, H. caprifoliatum, H. carinatum, H. connatum, H. linoides, H. myrianthum, H. polyanthemum and H. salvadorense) and to Peruvian Páramos (H. andinum and H. laricifolium); the supercritical CO2 extraction and analysis of the phenolic compounds of H. carinatum; the antifungal and antichemotactic activities of the lipophilic extracts from H. caprifoliatum, H. carinatum, H. linoides, H. myrianthum and H. polyanthemum. For the experiments, aerial parts in blossom were harvested (2008 - 2010). All collections were authorized by competent agencies of environmental protection. The extraction methods employed were static maceration, ultrasonic bath or supercritical CO2 (temperature = 40, 50 or 60ºC; pressure = 90, 120, 150 or 200 bar). HPLC analyses were carried out in reverse phase column (C18), isocratic system composed of acetonitrile, water and trifluoroacetic acid, and ultraviolet detection (220, 270 or 254 nm). Peaks were identified by comparison of retention times / co-injection with standards and quantified by calibration curve of the compounds. Antifungal and antichemotactic tests were performed using the broth microdilution assay and neutrophils migration inhibition method. The dimeric phloroglucinol uliginosin B (0.008 - 0.188%) and the flavonoid hyperoside (0.057 - 5.987%) were the main metabolite detected in flowers of the investigated species. Hypericum caprifoliatum and H. andinum displayed higher yields of these compounds, respectively. Japonicin A was found in seven species studied at concentrations that varied from 0.003 to 0.087% (H. myrianthum). The yield of hyperbrasilol B ranged from 0.006% in H. laricifolium to 0.011% in H. caprifoliatum. The benzopyrans (HP1 = 0.200%, HP2 = 0.225% and HP3 = 0.327%) and benzophenones (cariphenone A = 0.309% and cariphenone B = 0.062%) occurred exclusively in H. polyanthemum and H. carinatum. Maximum amounts of chlorogenic acid, isoquercitrin, quercitrin and guaijaverin were observed, respectively, in H. campestre (1.458%), H. andinum (1.161%), H. carinatum (0.231%) and H. laricifolium (0.404%). Such results provide a further support for the chemotaxonomic significance of the dimeric phloroglucinols. Temperature (40°C = 3.04%, 50°C = 2.21% and 60°C = 1.05%) and pressure (90 bar = 0.95%, 150 bar = 0.97% and 200 bar = 1.89%) critical did affect differently the yield of supercritical extract of H. carinatum. Despite lower yield in comparison to n-hexane extract (6.09%), supercritical CO2 extraction proved to be more selective than maceration. In optimal conditions (40°C, 90 bar and 180 minutes), the maximum amount of uliginosin B, cariphenone A and cariphenone B was, respectively, 162.83, 376.33 and 48.79%. Lastly, the mathematical model used in the process of supercritical extraction was properly correlated to the experimental data. Regarding the biological activities, all investigated species exhibited a broad spectrum of antifungal action as well as reduced neutrophils migration. Hypericum carinatum, H. linoides and H. myrianthum extracts presented the lowest value of minimum inhibitory concentration against Cryptococcus neoformans (MIC ≤ 15.6 μg/mL), Rhodotorula mucilaginosa (MIC ≤ 62.5 μg/mL), Candida glabrata and C. tropicalis (MIC range = 1.9 - 250 μg/mL). For these plants, the antichemotactic effect varied from 60-100% at concentrations of 0.31 to 10 μg/mL. The most active extracts were that presented high amounts of uliginosin B, japonicin A and hyperbrasilol B. Thus, the Hypericum species native to Southern Brazil show potential as source of new anti-infectives and anti-inflammatory drugs.

Um método confiável e eficiente por cromatografia líquida de alta eficiência (CLAE) foi desenvolvido para o controle de qualidade de extratos de P. incarnata. O método desenvolvido inclui uma estratégia original para identificação preliminar da espécie e operação simples baseada no modo de eluição isocrático. Este método foi validado para os flavonoides C-glicosilados vitexina e isovitexina, considerados marcadores da espécie e, aplicado na análise qualitativa e quantitativa de quatorze formulações comerciais com insumo vegetal composto exclusivamente de P. incarnata As análises foram realizadas com uma coluna C18 e à temperatura ambiente. Os comprimentos de onda de detecção foram 330 (vitexina e isovitexina) e 254 nm (rutina, marcador de contaminação). O método analítico foi linear para vitexina no intervalo de 5 - 40 ug/mL e para isovitexina no intervalo 5 - 60 ug/mL. Das quatorze amostras analisadas, oito eram em forma farmacêutica líquida (FFL) e seis em forma farmacêutica sólida (FFS). Seis amostras comerciais em FFL e seis amostras em FFS apresentaram perfil compatível com P. incarnata. As concentrações obtidas para as FFL foram vitexina 17,87 - 29,13 ug/mL e isovitexina 27,47 - 65,07 ug/mL, respectivamente. As FFS apresentaram concentração de vitexina entre 10,0 - 32,26 ug/mL e isovitexina 36,16 - 100,83 ug/mL. O método demonstrou ser confiável e eficiente para análise qualitativa e quantitativa de vitexina e isovitexina nos extratos; por esta razão foi considerado viável para a prática diária do controle de qualidade. A análise por cromatografia de líquida de alta eficiência acoplada com detector de espectroscopia de massas (CLAE-EM) foi realizada para investigar os principais fitoconstituintes, sete picos do extrato puderam ser resolvidos; e, forneceram fortes evidências sobre a composição química do extrato de P. incarnata. / A reliable and efficient method of high-performance liquid chromatography was developed for the quality control of Passiflora incarnata extracts. The quality control includes an original preliminary identification of this species and simple operation process based on isocratic elution. This method was validated for vitexin and isovitexin, C-glycoside flavonoids, considered markers of this species and applied to qualitative and quantitative analysis of fourteen commercial herbal medicines of P. incarnata extracts. Analysis was achieved on reversed-phase C18 column at ambient temperature. The wavelengths used for detection were 330 nm (vitexin and isovitexin) and 254 nm (rutin, a marker of contamination). Method was linear over vitexin concentration range of 540 g/mL and isovitexin 560 g/mL. Among of fourteen samples, eight were in liquid dosage form (LDF) and six in solid dosage form (SDF). Six commercial samples in LDF and six samples in SDF showed profile compatible with P. incarnata. Concentrations were determined for LDF vitexin 17.87  29.13 g/mL and isovitexin 27.47  65.07 g/mL. While SDF samples showed vitexin concentration range 10.00  32.26 g/mL and isovitexin 36.16  100.83 g/mL. The method demonstrated to be reliable and efficient for assay and qualitative analysis of vitexin and isovitexin in P. incarnata extracts; for that reason for practical application on quality control. Analysis were performed through high-performance liquid chromatography coupled with mass spectrometer detector (LC/MS) to investigate the main phytoconstituents, seven peaks from P. incarnata extract could be resolved; and provided strong evidences about the chemical composition of extracts.

Um método confiável e eficiente por cromatografia líquida de alta eficiência (CLAE) foi desenvolvido para o controle de qualidade de extratos de P. incarnata. O método desenvolvido inclui uma estratégia original para identificação preliminar da espécie e operação simples baseada no modo de eluição isocrático. Este método foi validado para os flavonoides C-glicosilados vitexina e isovitexina, considerados marcadores da espécie e, aplicado na análise qualitativa e quantitativa de quatorze formulações comerciais com insumo vegetal composto exclusivamente de P. incarnata As análises foram realizadas com uma coluna C18 e à temperatura ambiente. Os comprimentos de onda de detecção foram 330 (vitexina e isovitexina) e 254 nm (rutina, marcador de contaminação). O método analítico foi linear para vitexina no intervalo de 5 - 40 ug/mL e para isovitexina no intervalo 5 - 60 ug/mL. Das quatorze amostras analisadas, oito eram em forma farmacêutica líquida (FFL) e seis em forma farmacêutica sólida (FFS). Seis amostras comerciais em FFL e seis amostras em FFS apresentaram perfil compatível com P. incarnata. As concentrações obtidas para as FFL foram vitexina 17,87 - 29,13 ug/mL e isovitexina 27,47 - 65,07 ug/mL, respectivamente. As FFS apresentaram concentração de vitexina entre 10,0 - 32,26 ug/mL e isovitexina 36,16 - 100,83 ug/mL. O método demonstrou ser confiável e eficiente para análise qualitativa e quantitativa de vitexina e isovitexina nos extratos; por esta razão foi considerado viável para a prática diária do controle de qualidade. A análise por cromatografia de líquida de alta eficiência acoplada com detector de espectroscopia de massas (CLAE-EM) foi realizada para investigar os principais fitoconstituintes, sete picos do extrato puderam ser resolvidos; e, forneceram fortes evidências sobre a composição química do extrato de P. incarnata. / A reliable and efficient method of high-performance liquid chromatography was developed for the quality control of Passiflora incarnata extracts. The quality control includes an original preliminary identification of this species and simple operation process based on isocratic elution. This method was validated for vitexin and isovitexin, C-glycoside flavonoids, considered markers of this species and applied to qualitative and quantitative analysis of fourteen commercial herbal medicines of P. incarnata extracts. Analysis was achieved on reversed-phase C18 column at ambient temperature. The wavelengths used for detection were 330 nm (vitexin and isovitexin) and 254 nm (rutin, a marker of contamination). Method was linear over vitexin concentration range of 540 g/mL and isovitexin 560 g/mL. Among of fourteen samples, eight were in liquid dosage form (LDF) and six in solid dosage form (SDF). Six commercial samples in LDF and six samples in SDF showed profile compatible with P. incarnata. Concentrations were determined for LDF vitexin 17.87  29.13 g/mL and isovitexin 27.47  65.07 g/mL. While SDF samples showed vitexin concentration range 10.00  32.26 g/mL and isovitexin 36.16  100.83 g/mL. The method demonstrated to be reliable and efficient for assay and qualitative analysis of vitexin and isovitexin in P. incarnata extracts; for that reason for practical application on quality control. Analysis were performed through high-performance liquid chromatography coupled with mass spectrometer detector (LC/MS) to investigate the main phytoconstituents, seven peaks from P. incarnata extract could be resolved; and provided strong evidences about the chemical composition of extracts.

Résumé confidentiel / Résumé confidentiel

L'étude phytochimique de plantes médicinales suscite depuis toujours beaucoup d'intérêt à cause de la variété de métabolites secondaires à activités biologiques intéressantes fabriqués par les plantes. Dans ce travail de thèse, notre contribution à l'amélioration de la connaissance de quelques plantes médicinales ivoiriennes par l'isolement et la caractérisation de leurs molécules a été rapportée. Les espèces Gouania longipetala, Ventilago africana (Rhamnaceae), Combretum racemosum (Combretaceae) et Glyphaea brevis (Malvaceae) ont été investiguées. Soixante métabolites secondaires ont été identifiés par les techniques spectroscopiques (RMN et SM). Une première partie présente l'investigation phytochimique des parties aériennes de G. longipetala qui a conduit à l'isolement de 23 composés dont neuf saponosides à squelette de type dammarane et quatre hétérosides flavoniques de structures nouvelles. Dans un second temps, nos travaux ont mené à l'élucidation de 12 flavonoïdes dont deux nouveaux et un acide sesquiterpénique à partir des feuilles de V. africana. Ces flavonoïdes ont été identifiés à la rhamnocitrine substituée en position 3 par une chaîne diosidique ou triosidique. Les racines de Combretum racemosum ont fourni 16 triterpènes dont un à squelette de type 18-oléanène de structure nouvelle. Finalement, un dérivé du cinnamide et dix nouveaux C-glycosides de phényl nonane substitués en position 9 par un iminosucre ont été caractérisés à partir des racines de G. brevis. Cette étude correspond à la première identification structurale de métabolites secondaires des espèces Gouania longipetala, Ventilago africana (Rhamnaceae) et Combretum racemosum (Combretaceae). / The phytochemical study of medicinal plants has always raised a lot of interest because of the variety of secondary metabolites with interesting biological activities produced by plants. In this thesis, our contribution to improving the knowledge of some ivorian medicinal plants by the isolation and characterization of their molecules has been reported.Species Gouania longipetala, Ventilago africana (Rhamnaceae), Combretum racemosum (Combretaceae) and Glyphaea brevis (Malvaceae) were investigated. Sixty secondary metabolites were identified by spectroscopic techniques (NMR and MS).The first part presents the phytochemical investigation of the aerial parts of G. longipetala which led to the isolation of 23 compounds including nine new saponins with skeleton type dammarane and four new flavonoids glycosides.In a second step, our work has led to the elucidation of 12 flavonoids including two original and a sesquiterpene acid from the leaves of V. africana. These flavonoids have been identified as rhamnocitrin substituted at position 3 by a disaccharide or trisaccharide chain. The roots of Combretum racemosum provided 16 triterpenes and one of them is a new compound with a skeleton type 18-oleanene. Finally, a derivative of cinnamide and ten new alkyl phenyl C-glycosides substituted at position 9 by iminosugar have been characterized from the roots of G. brevis.This study represents the first structural identification of secondary metabolites of the species Gouania longipetala, Ventilago africana (Rhamnaceae) and Combretum racemosum (Combretaceae).

Aloe L. (Asphodelaceae) is a monocotyledonous group of considerable popularity among succulent plant collectors and with a long history of medicinal use. It comprises ca. 500 species occurring throughout Africa, the Arabian Peninsula and western Indian Ocean islands. The first comprehensive ethnobotanical study of Aloe (excluding the cultivated A. vera) was undertaken using the literature as a surrogate for data gathered by interview methods. Over 1400 use records representing 173 species were collated, the majority (74%) of which described medicinal uses, including species used for natural products. In southern Africa, 53% of approximately 120 Aloe species in the region are used for health and wellbeing. Consensus ratios indicated that the uses of Aloe spp. for medicine and pest control are of the greatest biocultural importance. Utility has contributed to the recognition of diversity, taxonomic complexity, and conservation concerns, in Aloe. A systematic evaluation of the problematic maculate (spotted) species complex, section Pictae, was undertaken. New sequences were acquired of the nuclear ribosomal internal transcribed spacer (ITS), chloroplast trnL intron, trnL–F spacer and matK gene in 29 maculate species of Aloe. A well supported monophyletic (holophyletic) maculate group was recovered in phylogenetic trees of comparable topology generated by parsimony analysis and Bayesian inference. A representative of the related section Paniculatae, A. striata, was recovered in the maculate group, whereas doubtful maculate species with unusual floral morphology (A. leptosiphon and A. suffulta) comprised a sister group. Analogous patterns were identified in chemosystematic and comparative morphological studies of 34 and 36 maculate species, respectively, and insights were gained into interspecific relationships. The flavonoids isoorientin and isovitexin, and a new C-glycosylanthrone, 6′-malonylnataloin, were characterised using hyphenated chromatographic techniques and nuclear magnetic resonance (NMR) spectroscopy. Leaf surface sculpturing, stomata and lobes surrounding the epistomatal pore observed under a scanning electron microscope (SEM) are of potential taxonomic significance. Available evidence indicates that floral characters, namely a basally swollen perianth with constriction above the ovary, are of greater significance than maculate leaves as synapomorphies for section Pictae. An evolutionary hypothesis for section Pictae excludes marginal maculate species with unusual flowers. / Thesis (PhD)--University of Pretoria, 2009. / Plant Science / unrestricted

L'approche écologique est une des stratégies de recherche de substances actives. Cette approche porte sur les plantes extrêmophiles, incluant les plantes halophytes et xérophytes, végétaux natifs des biotopes salins et arides. De par leur capacité à subsister dans un environnement contraignant, qui se traduit, entre autres, par l'acquisition d'un système antioxydant puissant, elles se révèlent être des réservoirs en biomolécules, notamment en composés phénoliques. Dans cette étude, nous nous sommes ainsi intéressés à huit plantes halophytes et xérophytes Tunisiennes pouvant avoir des activités biologiques en santé humaine et en santé du végétal. Limonium virgatum (Willd.) Fourr. (Plumbaginaceae), plante halophyte, a montré des activités antioxydantes et antibactériennes intéressantes qui se trouvent respectivement liées à un contenu en polyphénols élevé et à la présence de phénylpropanoïdes. Cirsium scabrum (Poir.) Bonnet & Barratte (Asteraceae), plante xérophyte, a montré une activité cytotoxique selective envers la lignée cancéreuse J774 mettant en avant l'efficacité de triterpènes de type cycloartane ; mais également un pouvoir antibactérien sur des souches de Dermabacter hominis, qui serait lié à la présence de flavones glycosylées. Juncus maritimus Lam. (Juncaceae), plante halophyte, s'est montrée être une source de dérivés phénanthréniques à activités originales. Le juncunol, a montré une activité prometteuse sur une souche de Streptococcus pyogenes résistante à l'amoxicilline. L'effusol actif sur le pathogène de la septoriose du blé (Zymoseptoria tritici), serait stimulé dans les rhizomes de la plante en conditions de salinité élevées. Enfin, le dehydrojuncusol s'est montré être un nouvel inhibiteur de la réplication du virus de l'hépatite C, capable d'agir sur des formes de résistance à certains traitement disponibles sur le marché. / Research strategies of active natural products include ecological approaches. Extremophile plants, and in particular, halophytes and xerophytes, salt and drought-resistant plants, are a case in point. As they develop an arsenal of adaptation responses, including a powerful antioxidant system, they prove to be a promising source of biomolecules, especially in phenolic compounds. In this study, an assessment of biological activities was carried out on eight Tunisian halophyte and xerophyte plants that would offer new applications in public health-care, as well as in agriculture. Limonium virgatum (Willd.) Fourr. (Plumbaginaceae), a halophyte plant, showed interesting antioxidant and antibacterial activities in accordance to a high polyphenol content and to the presence of phenylpropanoides, respectively. Cirsium scabrum (Poir.) Bonnet & Barratte (Asteraceae), a xerophyte plant, revealed a cytotoxic potential involving cycloartane-type triterpenes, and a promising activity against Dermabacter hominis strains which is linked to the presence of glycosylated flavones. Juncus maritimus Lam. (Juncaceae), a halophyte plant, should be referred to a source of phenanthrene derivativeswith original biological activities. Juncunol showed a high activity against an amoxicillin-resistant strain of Streptococcus pyogenes. Effusol was highly active against the wheat pathogen (Zymoseptoria tritici), for which high salinity conditions would stimulate its activity in the rhizomes of the plant. Most interestingly, dehydrojuncusol, has been introduced as a novel inhibitor of hepatitis C virus replication that is effective against resistant mutants for which some treatments available on the market became ineffective.

Machine learning is applied to a challenging and biologically significant protein classification problem: the prediction of flavonoid UGT acceptor regioselectivity from primary protein sequence. Novel indices characterizing graphical models of protein residues are introduced. The indices are compared with existing amino acid indices and found to cluster residues appropriately. A variety of models employing the indices are then investigated by examining their performance when analyzed using nearest neighbor, support vector machine, and Bayesian neural network classifiers. Improvements over nearest neighbor classifications relying on standard alignment similarity scores are reported.

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Submitted by ÍCARO PUTINHON CARUSO null (ykrocaruso@hotmail.com) on 2016-09-19T16:20:38Z No. of bitstreams: 1 tese_doutorado_icaro_vf.pdf: 17027642 bytes, checksum: 71d2f869670d044aace5f2ab6326b657 (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-09-22T14:26:36Z (GMT) No. of bitstreams: 1 caruso_ip_dr_sjrp.pdf: 17027642 bytes, checksum: 71d2f869670d044aace5f2ab6326b657 (MD5) / Made available in DSpace on 2016-09-22T14:26:36Z (GMT). No. of bitstreams: 1 caruso_ip_dr_sjrp.pdf: 17027642 bytes, checksum: 71d2f869670d044aace5f2ab6326b657 (MD5) Previous issue date: 2016-08-26 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os flavonóides fazem parte de uma ampla classe de compostos polifenólicos os quais ocorrem naturalmente nas plantas e podem ser encontrados nas sementes, caules, folhas, flores e/ou frutos. Estudos recentes indicam que esses compostos polifenólicos podem apresentar uma variedade significativa de atividades biológicas benéficas para a saúde humana, como por exemplo: antioxidante, anti-inflamatória, antibacteriana, antiviral e anticancerígena. A Albumina do Soro Humano (HSA) é a principal proteína extracelular presente no plasma sanguíneo. A função central dessa proteína é transportar e distribuir ligantes endógenos e exógenos para diferentes alvos moleculares no corpo humano. Por tais aspectos, torna-se importante o desenvolvimento de estudos que caracterizam a interação dos flavonóides com a proteína transportadora HSA. Este trabalho investiga a interação dos flavonóides Isovitexina (ISO) e 2-Fenilcromona (2PHE) com a HSA, utilizando técnicas experimentais de espectroscopia de fluorescência, absorbância UV-Vis, dicroísmo circular (CD) e infravermelho com transformada de Fourier (FT-IR); juntamente com ferramentas computacionais de cálculo {\it{ab initio}}, dinâmica molecular e modelagem molecular. A integração dessas abordagens experimentais e computacionais possibilita caracterizar a formação dos complexos HSA-flavonóides, determinando aspectos físico-químicos como: constantes de afinidade, parâmetros termodinâmicos, número de sítios de ligação, perfil de cooperatividade e resíduos de aminoácidos responsáveis pelas interações proteína-flavonóides (hidrofóbicas e eletrostáticas). / Flavonoids belong to a large class of polyphenolic compounds which occur naturally in plants and can be found seeds, stems, leaves, flowers and/or fruits. Recent studies indicate that these polyphenolic compounds can present a significant variety of beneficial biological activities on human health, such as: antioxidant, anti-inflammatory, antibacterial, antiviral, and anticancer. Human Serum Ambumin (HSA) is the main extracellular protein presents in blood plasma. The core function of this protein is to carry and distribute endogenous and exogenous ligands to different molecular targets in the human body. For these aspects, it is important to develop studies that characterize the interaction of the flavonoids with the carrier protein HSA. This work investigates the interaction of the flavonoids Isovitexin (ISO) and 2-Phenylchromone (2PHE) with the HSA, using experimental techniques of fluorescence, UV-Vis absorbance, circular dichroism (CD), and Fourier transform infrared (FT-IR) spectroscopy; along with computational tools of ab initio calculation, molecular dynamics, and molecular modeling. The integration of these experimental and computational approaches allows to characterize the formation of the HSA-flavonoids complexes, determining physicochemical aspects, sucha as: affinity constants, thermodynamic parameters, number of binding sites, cooperativity profile and aminoacid residues responsable for the protein-flavonoids interactions (hydrophobic and electrostatic).