As ciclodextrinas são oligossacarídeos descobertos há mais de cem anos e utilizados para modificação de propriedades físico-químicas de moléculas, aplicadas especialmente para aumentar/modificar sua solubilidade através da formação de complexos de inclusão tipo hóspede-hospedeiro entre sua cavidade apolar e grupamentos afins das moléculas hóspedes. O sucesso na obtenção dos complexos de inclusão depende muito do método empregado e é necessário conhecer as opções disponíveis para selecionar a melhor relação entre eficiência e rendimento. Dentre as técnicas utilizadas para a obtenção destes complexos as mais destacadas são a coprecipitação, coevaporação, neutralização, liofilização, spray-drying, malaxagem, moagem e fluidos supercríticos. O objetivo do presente trabalho foi avaliar a influência da complexação do pizotifeno (PZT) com ciclodextrinas (CDs) sobre a sua fotodegradação em solução aquosa. Para isso foram utilizados diferentes tipos de CDs (α, β e γ ). Adicionalmente, um método analítico indicador de estabilidade por cromatografia líquida de alta eficiência foi desenvolvido e validado. Este método cromatográfico foi avaliado quanto a sua seletividade, linearidade, precisão intermediária, exatidão, estimativas de limites inferiores de quantificação e detecção, robustez e saturação dos filtros. A coluna cromatográfica utilizada foi uma Wakosil II 5C18 RS, 250mm x 4,6mm (5µm). A fase móvel (FM) utilizada consistiu numa mistura de solução aquosa de (NaH2PO4 + Pic B8) 2 mmol/l:acetonitrila:trietilamina (600:400:2, v/v) com pH aparente de 3,00±0,05. A vazão de trabalho utilizada foi de 1,5 ml/min e a temperatura da coluna foi mantida a 30°C. O método avaliado mostrou-se capaz de separar o PZT de seus principais produtos de degradação, preciso, exato, satisfatoriamente linear (r2>0,99, intercepto-y próximo de zero), robusto quanto ao pH, composição e vazão da FM e a condição de filtração ideal foi através de filtros de PVDF hidrofílico. A mudança na fotoestabilidade do pizotifeno puro e complexado com α, β e γ ciclodextrinas em solução aquosa foi avaliada em câmara de fotoestabilidade sob luz branca e UV por doze dias em frascos de vidro lacrados. Os complexos de inclusão conferiram ao fármaco uma velocidade de degradação no mínimo 19% menor em relação ao PZT puro e uma proteção relativa de até 1,61. A magnitude da fotoproteção foi maior para o complexo formado com β-ciclodextrina independentemente do tipo de radiação. / Cyclodextrins (CDs) are oligosaccharides discovered over one hundred years ago and used to change physicochemical properties of molecules, acting especially over its aqueous solubility through the formation of guest-host type inclusion complexes between its apolar cavity and similar structures in the guest molecule. Among the techniques employed to obtain these inclusion complexes the most commonly used are coprecipitation, coevaporation, neutralization, freeze-drying, spray-drying, kneading, grinding and precipitation from supercritical fluids. The objective of the present work was to evaluate the influence of the complexation of pizotifen (PZT) with various CDs (α, β and γ) over its photostability in aqueous solution. Also, a stability indicating high performance chromatographic method was developed and fully validated regarding its selectivity, linearity, intermediate precision, accuracy, lower limits of detection and quantification, robustness and filter saturation. The column used was a Wakosil II 5C18 RS with (250 x 4,6) mm, 5 µm particle size and kept at 30°C. The mobile phase (MP) used consisted of a mixture of a saline aqueous solution (NaH2PO4 + Sodium Octanesulfonate) 2 mmol/l:acetonitrile:tryethylamine (600:400:2 v/v) with its apparent pH adjusted to 3 and with a flow rate of 1,5 ml/min. The method was selective regarding PZT peak even among its degradation products and also precise, exact, linear (r2>0,99 and y-intercept close to zero), robust regarding MP\'s pH, composition and flow rate and the best filtration condition was with hydrophilic PVDF. Photostability changes in pure and complexed PZT in aqueous solution inside sealed glass vials were assessed for 12 days under both white and UV light in a photostability chamber regarding PZT\'s observed degradation rate, half-life and relative protection. Inclusion complexation significantly reduced PZT\'s degradation constant at least 20%, with equivalent increase in its half-life and a maximum relative protection of 1,61. The most significant protection was observed in the β-CD complex solution for both types of irradiation.

Les lectines sont des protéines qui reconnaissent les glucides complexes de manière spécifique et réversible. L'amibe Dictyostelium discoideum est un organisme modèle eucaryote très employé pour l'étude de nombreux processus biologiques tel la phagocytose, la différenciation ou la mort cellulaire. Lorsqu'elle se différencie suite à une absence de nutriments, elle produit au cours de la phase d'agrégation, deux lectines qui reconnaissent le Gal/GalNAc : les discoidines (DiscI et DiscII). DiscI et DiscII présentent 48% d'identité de séquence, forment des trimères en solution et partagent la même organisation en domaine. Un domaine discoidine (domaine DS) impliqué dans les processus d'adhésion cellulaire est retrouvé en N-terminal suivi d'un domaine lectine de type H en C-terminal. Le domaine lectine présente des similarités avec la lectine d'escargot HPA. Cette lectine spécifique du GalNAc est utilisée extensivement en histopathologie comme marqueur des cellules tumorales à fort caractère métastatique. Les travaux de recherche développés dans cette thèse portent sur l'étude structurale et fonctionnelle de l'interaction de DiscI et DiscII avec les sucres Gal/GalNAc selon une approche pluridisciplinaire. Ces deux lectines ont été clonées, exprimées sous forme recombinante dans Escherichia coli avant d'être purifiées. Leur spécificité et leur affinité ont été déterminées par l'utilisation de puces à sucres et par microcalorimétrie de titration. L'analyse des interactions à un niveau oléculaire s'est réalisée suite à la détermination de leur structure 3-D sous forme native ou complexée par cristallographie aux rayons X. La comparaison des sites de liaison entre les Discoidines et HPA a permis une meilleure compréhension des leurs mécanismes de reconnaissance, de spécificité et d'affinité à niveau moléculaire.

Certaines fibres alimentaires réduiraient l'apparition des cancers colorectaux mais l'hypothèse reste contreversée. Un des mécanismes fait intervenir la production par fermentation de butyrate. Nous avons testé deux fibres butyrogènes chimiquement différentes (fructo-oligosaccharides à chaîne courte scFOS, et amidon résistant) versus une fibre faiblement productrice de butyrate (son de blé désamidonné) chez la souris Min, un modèle de carcinogenèse intestinale spontanée. Seul le régime scFOS réduisait le nombre de tumeurs coliques et stimulait l'immunité locale. La nature chimique de la fibre ou bien les propriétés prébiotiques des scFOS (ils favorisent la croissance de bactéries lactiques qui agiraient sur la réaction immunitaire) sont donc impliquées. Deux autres types d'amidons résistants réduisaient le nombre de petites tumeurs. L'addition de bifidobactéries à l'un de ces deux régimes réduisait le nombre de petites tumeurs, mais augmentait celui de grosses tumeurs illustrant le concept de modulation par l'immunogénicité de la dualité immunofacilitation/surveillance. La déplétion en lymphocytes T associée au régime scFOS doublait le nombre de tumeurs par rapport aux souris immunocompétentes. Le régime scFOS diminuait l'expression du récepteur à l'IL2 à la surface des lymphocytes intra-épithéliaux (LIE) suggérant la mise en anergie temporaire du système immunitaire, mais pouvant aussi signifier l'implication d'une autre voie d'activation des LIE. Enfin, pour mettre en place une modélisation des intéractions lympho-épithéliales, nous avons croisé des souris C57BL6 et Min avec la souris transgénique Immortomouse et isolé à partir de primo-cultures de muqueuses des lignées cellulaires conditionnellement immortalisées saines et mutées sur Apc. Ce modèle permettra d'étudier en co-culture sur filtre, l'influence des glucides indigestibles et de leurs produits de fermentation sur les interactions lympho-épithéliales au cours de la carcinogenèse.

<p>Oligosaccharides (carbohydrates) are a large class of biological molecules that are important as energy sources in the human body and have enormously varied biological functions. It is generally believed that biological activities of carbohydrates are related to their internal dynamics. The dynamic properties of some oligosaccharides in solution are studied in this thesis, by NMR relaxation. We have employed relaxation interference effects to investigate the conformational dynamics within oligosaccharides (in-tramolecular dynamics) and paramagnetic relaxation enhancement (PRE) as an experimental tool to study intermolecular dynamics. Most of the thesis concerns the dynamics of the methylene group in the two possibly mobile parts of the oligosaccharide: in the exocyclic hydroxymethyl moiety and in the glycosidic linkage position. To perform conformational dynamic studies, the more traditional auto-relaxation pa-rameters are combined with the relaxation interference terms or the cross-correlated relaxation rates (CCRRs). Some experimental schemes based on the initial-rate technique were developed for measuring CCRRs. The techniques are useful for labelled sugars as well as naturally abundant ones. Furthermore, various dynamical models ranging from the Lipari–Szabo approach to several more informative and complicated models such as the two-site jump model, restricted internal rotation and slowly relaxing local structure (SRLS), have been employed to interpret our experimental data. We have combined and com-pared different models; we have also developed a novel approach to existing models, by scaling dipolar coupling constants (DCC), to extract the dynamic behaviour and structural properties of the system. We found that the auto- and cross-correlated relaxation data analyses yield a consistent picture of the dynam-ics in all cases. Additionally, our investigations show that CCRRs are practically important for verifica-tion of certain dynamical and structural information that is difficult to be determined by other means. Moreover, the anisotropy of the carbon-13 chemical shielding tensor in the methylene group has been estimated, using the interference between dipole-dipole and chemical shift anisotropy.</p><p>This thesis also discusses using the PRE to investigate sugar dynamics relative to a paramagnetic MRI contrast agent in solution, which might be important in medicine. We have studied the intramolecu-lar dynamics of the trisaccharide raffinose in the presence of a gadolinium complex. We also investigated the effect of translational diffusion instead of rotational diffusion, which is normally more important in NMR. The paramagnetically enhanced spin–lattice relaxation rates of aqueous protons over a wide range of magnetic fields and of carbon-13 and protons of the sugar at high fields have been measured. The nuclear magnetic relaxation dispersion of water protons and the PREs of proton and carbon in the sugar are interpreted in terms of the model recently developed in our laboratory, allowing both outer- and inner-sphere PREs for water protons, but allowing only the outer sphere PRE for nuclei in the sugar. We found that the relative diffusion has a stronger effect on the PRE than the electron spin relaxation.</p>

Oligosaccharides (carbohydrates) are a large class of biological molecules that are important as energy sources in the human body and have enormously varied biological functions. It is generally believed that biological activities of carbohydrates are related to their internal dynamics. The dynamic properties of some oligosaccharides in solution are studied in this thesis, by NMR relaxation. We have employed relaxation interference effects to investigate the conformational dynamics within oligosaccharides (in-tramolecular dynamics) and paramagnetic relaxation enhancement (PRE) as an experimental tool to study intermolecular dynamics. Most of the thesis concerns the dynamics of the methylene group in the two possibly mobile parts of the oligosaccharide: in the exocyclic hydroxymethyl moiety and in the glycosidic linkage position. To perform conformational dynamic studies, the more traditional auto-relaxation pa-rameters are combined with the relaxation interference terms or the cross-correlated relaxation rates (CCRRs). Some experimental schemes based on the initial-rate technique were developed for measuring CCRRs. The techniques are useful for labelled sugars as well as naturally abundant ones. Furthermore, various dynamical models ranging from the Lipari–Szabo approach to several more informative and complicated models such as the two-site jump model, restricted internal rotation and slowly relaxing local structure (SRLS), have been employed to interpret our experimental data. We have combined and com-pared different models; we have also developed a novel approach to existing models, by scaling dipolar coupling constants (DCC), to extract the dynamic behaviour and structural properties of the system. We found that the auto- and cross-correlated relaxation data analyses yield a consistent picture of the dynam-ics in all cases. Additionally, our investigations show that CCRRs are practically important for verifica-tion of certain dynamical and structural information that is difficult to be determined by other means. Moreover, the anisotropy of the carbon-13 chemical shielding tensor in the methylene group has been estimated, using the interference between dipole-dipole and chemical shift anisotropy. This thesis also discusses using the PRE to investigate sugar dynamics relative to a paramagnetic MRI contrast agent in solution, which might be important in medicine. We have studied the intramolecu-lar dynamics of the trisaccharide raffinose in the presence of a gadolinium complex. We also investigated the effect of translational diffusion instead of rotational diffusion, which is normally more important in NMR. The paramagnetically enhanced spin–lattice relaxation rates of aqueous protons over a wide range of magnetic fields and of carbon-13 and protons of the sugar at high fields have been measured. The nuclear magnetic relaxation dispersion of water protons and the PREs of proton and carbon in the sugar are interpreted in terms of the model recently developed in our laboratory, allowing both outer- and inner-sphere PREs for water protons, but allowing only the outer sphere PRE for nuclei in the sugar. We found that the relative diffusion has a stronger effect on the PRE than the electron spin relaxation.

La colonisation chronique des poumons par P. aeruginosa est une cause majeure d'infection<br />et de mortalité chez les patients atteints de mucoviscidose (CF). Pour la bactérie pathogène, la<br />capacité à adhérer aux cellules hôtes est essentielle pour initier l'infection, et les<br />glycoconjugés présents à la surface des cellules épithéliales sont autant de cibles pour les<br />récepteurs bactériens. Chez les patients CF, des modifications surviennent dans les<br />glycoconjugués des surfaces épithéliales ainsi que dans les mucines pulmonaires et salivaires.<br />Une augmentation d'oligosaccharides fucosylés de type Lewis est observée, souvent<br />accompagnée de sialylation et/ou sulfatation.Une lectine soluble, PA-IIL, reconnaissant<br />spécifiquement le fucose, a été identifiée dans le cytoplasme de P. aeruginosa. Cette lectine,<br />également présente sur la surface de la bactérie, pourrait être impliquée dans la<br />reconnaissance de l'hôte et/ou dans la formation du biofilm responsable de la résistance de la<br />bactérie contre les antibiotiques. Les travaux développés dans la thèse portent sur l'étude<br />structurale et thermodynamique de l'interaction de PA-IIL avec des ligands naturels et des<br />glycomimétiques de synthèse. Des tests d'interaction ELLA (Enzyme-Linked Lectin Assays)<br />ont été mis en place afin d'évaluer les propriétés inhibitrices de ces composés. Ces travaux<br />constituent une première approche dans la conception de composés dérivés des sucres<br />pouvant servir comme alternative aux antibiotiques utilisés dans les infections survenants<br />chez les patients atteints de mucoviscidose. (Projet financé par l'association: Vaincre la<br />Mucoviscidose)

Reproduction de : Thèse de doctorat : Stratégie d'exploitation des fonctions biologiques : Lille 1 : 2004. / Résumé en français et en anglais. Titre provenant de la page de titre du document numérisé. Bibliogr. f. 107-123.

Made available in DSpace on 2016-12-23T13:50:02Z (GMT). No. of bitstreams: 1 Rayana Pinheiro Viana.pdf: 1511945 bytes, checksum: 9929e64da8465eb2d080c71e13b5d83c (MD5) Previous issue date: 2013-08-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O yacon é uma raiz tuberosa ainda pouco consumida no Brasil, sendo ultimamente muito estudada na saúde humana devido à presença dos fruto-oligossacarídeos (FOS). No presente estudo foi produzida a farinha de yacon e avaliou-se a influência de sua ingestão por mulheres portadoras de diabetes tipo 2 durante 60 dias (T0: início; T30: após 30 dias; T60: após 60 dias). As participantes foram divididas em grupo controle (GC: n = 29) e grupo yacon (GY: n = 23), que consumiu 11 g de FOS presentes na farinha de yacon. Foram avaliados os parâmetros de glicose em jejum, perfil lipídico, composição corporal e consumo alimentar, adotando um nível de 5% de significância nos testes estatísticos. A farinha de yacon apresentou 6,50% de rendimento, 1,15% de umidade, 4,52% de proteína total, 0,33% de gordura, 2,94% de cinzas, 10,23% de fibra bruta, 91,0% de carboidratos totais e 35,06% de FOS. No GY foi encontrado aumento significativo do HDL entre os três tempos do estudo (p < 0,0001) e também de colesterol total de T0 para T60 (p = 0,03) e redução significativa do percentual de gordura corporal de T0 para T60 (p = 0,03). No GC, um aumento significativo foi encontrado no HDL de T0 e T30 para T60 (p < 0,0001) e de triacilgliceróis de T0 para T30 (p = 0,01). Em relação ao consumo alimentar, houve diferença significativa entre os grupos em relação às fibras em T30 e T60 (p = 0,01/p = 0,009). O GY apresentou uma redução significativa de calorias (p = 0,02) e ácidos graxos saturados (p = 0,02) de T0 para T60, enquanto o GC apresentou redução significativa da ingestão de carboidratos de T0 para T30 (p = 0,03). A diminuição do percentual de gordura corporal e da ingestão energética do GY sugere um possível efeito benéfico dos FOS / The yacon is a tuberous root poorly consumed in Brazil lately been much studied on human health due to the presence of fructo-oligosaccharides (FOS). In the present study was produced flour from the yacon pulp and evaluated the influence of its intake of women with type 2 diabetes, during a period of 60 days (T0: in the beginning of the study; T30: after 30 days; T60: after 60 days). The participants were divided in a control group (CG: n = 29) and yacon group (YG: n = 23) who consumed 11 g of FOS present in yacon flour. The parameters evaluated were fasting glucose, lipid profile, body composition and the evaluation of food intake, adopting a 5% level of significance in statistical tests Yacon flour presented 6.50% of yield, 1.15% of moisture, 4.52% of total protein, 0.33 % of fat, 2.94% of ash, 10.23% of crude fiber, 91.0% of total carbohydrate and 35.06 % of FOS. In YG was observed a significant increase of HDL for the three study period (p < 0.0001), but there was also an increase of total cholesterol of T0 to T60 (p = 0.03) and significant reduction in percentage of body fat for T0 to T60 (p = 0.03). In the CG a significant increase was found for the HDL from T0 and T30 to T60 (p < 0.0001) parameters and triglycerides from T0 to T30 (p = 0.01). In the relation to the food intake, there was a significant difference between the groups in relation to the fiber in T30 and T60 (p = 0.01/p = 0.009). YG presented a significant reduction of calories (p = 0.02) and saturated fatty acids (p = 0.02) of T0 to T60 and CG a significant reduction of carbohydrate intake of T0 to T30 (p = 0.03). The decrease in the percentage of body fat and energy intake of the GY suggests a possible beneficial effect of FOS

Orientador: Edivaldo Antônio Garcia / Resumo: O experimento foi realizado no setor de avicultura da Faculdade de Medicina Veterinária e Zootecnia, Câmpus de Botucatu, com o objetivo de avaliar os efeitos da inclusão de flavonóides juntamente com mananoligossacarídeos (mos) frente a outros aditivos sobre o desempenho, rendimento da carcaça e de partes e qualidade da carne de frangos de corte criados no período de 1 a 42 dias. Foram utilizados 1500 frangos de corte da linhagem Cobb, distribuídos em um delineamento inteiramente casualizado com cinco tratamentos e seis repetições de 50 aves por parcela, para análise de desempenho nos períodos de 1 - 21, 22 - 42, 22 - 35, 36 - 42 e 1 - 42 dias. Os tratamentos consistiram em antibiótico, probiótico 1, probiótico 2, testemunha e flavonóide + mos. Aos 42 dias foram retiradas 24 aves por tratamento para as análises de rendimento de carcaça, de partes e qualidade de carne. A análise estatística dos dados foi realizada pelo SISVAR (Ferreira, 1998). Não houve diferença significativa entre os tratamentos para ganho de peso diário, consumo de ração, mortalidade, conversão alimentar e peso médio final nos períodos de 1 - 21, 22 - 42, 22 - 35, 36 - 42. No período de 1 - 42 dias também não houve diferença significativa entre os tratamentos para ganho de peso diário, consumo de ração, mortalidade e peso médio final mas houve diferença significativa para conversão alimentar, onde o tratamento flavonóide + mos apresentou o melhor índice. O rendimento de carcaça e de partes não foi alterado significativamente entre os tratamentos. As análises de qualidade de carne para pH e coloração... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The experiment was carried out at the School of Veterinary and Animal Science, FMVZ, Unesp, Botucatu. The study aimed to evaluated to effect of the use of flavonoids + mannan oligosaccharides (mos) and others growth promoters on performance, carcass yield and cuts, meat quality of broilers reared from 1 - 42 days. This experimental design was the completely randomized. One thousand and fifty male Cobb broiler chicks were distributed in five treatment with six replicates of 50 birds each. Growth performance data were obtained from 1 - 21, 22 - 42, 22 - 35, 36 - 42 and 1 - 42 days period. The treatments were denominated as: antibiotic, probiotic 1, probiotic 2, negative control and flavonoids + mos. At 42 days of age, twenty four birds from each treatment were slaughtered to evaluate carcass yield and cuts, and meat quality. Experiment data were calculated and analyzed using SISVAR (Ferreira, 1998). There were no significant effects of treatments on growth performance data were obtained from 1 - 21, 22 - 42, 22 - 35, 36 - 42 days period. In the total period, 1 - 42 days, the results showed that there were no significant of treatment effect on mortality, weight gain, feed consumption, live weight and efficiency production factor but there were significant effect on feed convertion, the treatment flavonoids + mos was better when compared with other treatments. There were no significant effects of treatments on carcass yield, yield cuts, pH and color. There were significant effects of treatments on Tbars (this analysis show the oxidative stability) to breast and thig meat, the treatment flavonoids + mos. was better when compared with other treatments. / Mestre

Made available in DSpace on 2014-12-17T15:01:16Z (GMT). No. of bitstreams: 1 RaimundoCSF.pdf: 2059810 bytes, checksum: 4d1a84d062e046ae8304a415fa8bdd6b (MD5) Previous issue date: 2005-12-13 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In this work a 24 factorial design with triplicate at central point was used in order to investigate the influence of chitosan concentration (substrate) (Cs), culture media temperature (CMT), aeration ratio (AR) as well as agitation (A) on chitosanase production by Aspergillus ochraceus. Experiments were carried out using the following levels to the factors: (Cs) (-1) 0.1%; (0) 0.15%; (+1) 0.2%; (TMC) (-1) 25 minutes; (0) 30 minutes; (+1) 35 minutes; (RA) (-1) 0.4; (0) 0.6; (+1) 0.8; (A) (-1) 90 rpm, (0) 120 rpm, (+1) 150 rpm. One chitosanolytic activity (U.mL-1) was defined as the enzyme necessary to produce 1.0 mmol.min-1 of glicosamine by mL of extract. Chitosanolytic assays were carried out using two extract volumes, 0.05 and 0.1 mL, respectively. Results showed that was possible to produce chitosanase of order aproximatelly 5,9 U.mL-1 by Aspergillus ochraceus and chitosanolytic activity was increased by increment on substrate concentration, aeration ratio as well as agitation while media culture temperature increment decreased activity / No presente trabalho utilizou-se um planejamento fatorial 24 com repeti??o em triplicata no ponto central, para se investigar a influ?ncia dos fatores: concentra??o de quitosana (substrato) (Cs), temperatura de cultivo (TMC), raz?o de aera??o (RA) e agita??o (A) na produ??o da enzima quitosanase por Aspergillus ochraceus. Os ensaios foram realizados aleatoriamente utilizando-se os seguintes n?veis para os fatores: (Cs) (-1) 0,1%; (0) 0,15%; (+1) 0,2%; (TMC) (-1) 25 minutos; (0) 30 minutos; (+1) 35 minutos; (RA) (-1) 0,4; (0) 0,6; (+1) 0,8; (A) (-1) 90 rpm, (0) 120rpm, (+1) 150 rpm. Uma unidade de atividade quitosanol?tica (U.mL-1) foi definida como a quantidade de enzima necess?ria para produzir (1,0 mmol.min-1) de glicosamina por mL de extrato enzim?tico. Para o teste de atividade quitosanol?tica foram utilizados dois volumes diferentes de caldo enzim?tico 0,05 mL e 0,1 mL, respectivamente. Os resultados mostraram que foi poss?vel produzir quitosanase em concentra??o aproximada de 5,9 U.mL-1 utilizando Aspergillus ochraceus e que a atividade foi favorecida pelo aumento da agita??o (A), da raz?o de aera??o (RA) e da concentra??o de substrato (Cs), enquanto que o aumento da temperatura de cultivo (TMC) n?o favoreceu a resposta (atividade quitosanol?tica)