Patients on anti-retroviral (ARV) drug treatment are sometimes simultaneously taking other prescribed drugs and/or over-the-counter drugs and/or herbal remedies. Pharmacokinetic drug-drug or herb-drug interactions can occur in these patients, which might be synergistic or antagonistic in nature leading to increased or decreased bioavailability of the ARV. Consequences of bioavailability changes may either be adverse effects due to increased plasma levels, or lack of pharmacological responses due to decreased plasma levels. The aim of this study is to determine if pharmacokinetic interactions exist between selected commercially available herbal products, namely Linctagon Forte®, Viral Choice® and Canova® and the ARV, indinavir, in terms of transport and metabolism in cell culture models. Bi-directional transport of indinavir was evaluated across Caco-2 cell monolayers in four experimental groups, namely indinavir alone (200 μM, negative control group), indinavir in combination with Linctagon Forte®, indinavir in combination with Viral Choice® and indinavir in combination with Canova® at three different concentrations. Verapamil (100 μM), a known P-gp inhibitor, was combined with indinavir in the positive control group. Samples obtained from the transport studies were analysed by means of a validated high performance liquid chromatography (HPLC) method. The apparent permeability coefficient (Papp) values were calculated from the transport results in both directions and the efflux ratio (ER) values were calculated from these Papp values. The metabolism of indinavir was determined in LS180 cells in the same groups as mentioned for the transport study but with ketoconazole (40 μM), a known CYP3A4 inhibitor, as the positive control group. Indinavir and its predominant metabolite (M6) were analysed in the metabolism samples by means of liquid chromatography linked to mass spectroscopy (LC/MS/MS) to determine the effect of the herbal products on the biotransformation of indinavir. The BL-AP transport of indinavir increased in a concentration dependent way in the presence of Linctagon Forte® and Viral Choice® when compared to that of indinavir alone (control group). Canova® only slightly affected the efflux of indinavir compared to that of the control group. Noticeable increases in the efflux ratio values of indinavir were found for Linctagon Forte® and Viral Choice®, whilst the effect of Canova® on the efflux ratio value was negligible. There was a pronounced inhibition of the metabolism of indinavir in LS180 cells over the entire concentration range for all the herbal products investigated in this study. These in vitro pharmacokinetic interactions indicate the selected herbal products may affect indinavir’s bioavailability, but the clinical significance needs to be confirmed with in vivo studies before final conclusions can be made. / MSc (Pharmaceutics), North-West University, Potchefstroom Campus, 2015

Patients on anti-retroviral (ARV) drug treatment are sometimes simultaneously taking other prescribed drugs and/or over-the-counter drugs and/or herbal remedies. Pharmacokinetic drug-drug or herb-drug interactions can occur in these patients, which might be synergistic or antagonistic in nature leading to increased or decreased bioavailability of the ARV. Consequences of bioavailability changes may either be adverse effects due to increased plasma levels, or lack of pharmacological responses due to decreased plasma levels. The aim of this study is to determine if pharmacokinetic interactions exist between selected commercially available herbal products, namely Linctagon Forte®, Viral Choice® and Canova® and the ARV, indinavir, in terms of transport and metabolism in cell culture models. Bi-directional transport of indinavir was evaluated across Caco-2 cell monolayers in four experimental groups, namely indinavir alone (200 μM, negative control group), indinavir in combination with Linctagon Forte®, indinavir in combination with Viral Choice® and indinavir in combination with Canova® at three different concentrations. Verapamil (100 μM), a known P-gp inhibitor, was combined with indinavir in the positive control group. Samples obtained from the transport studies were analysed by means of a validated high performance liquid chromatography (HPLC) method. The apparent permeability coefficient (Papp) values were calculated from the transport results in both directions and the efflux ratio (ER) values were calculated from these Papp values. The metabolism of indinavir was determined in LS180 cells in the same groups as mentioned for the transport study but with ketoconazole (40 μM), a known CYP3A4 inhibitor, as the positive control group. Indinavir and its predominant metabolite (M6) were analysed in the metabolism samples by means of liquid chromatography linked to mass spectroscopy (LC/MS/MS) to determine the effect of the herbal products on the biotransformation of indinavir. The BL-AP transport of indinavir increased in a concentration dependent way in the presence of Linctagon Forte® and Viral Choice® when compared to that of indinavir alone (control group). Canova® only slightly affected the efflux of indinavir compared to that of the control group. Noticeable increases in the efflux ratio values of indinavir were found for Linctagon Forte® and Viral Choice®, whilst the effect of Canova® on the efflux ratio value was negligible. There was a pronounced inhibition of the metabolism of indinavir in LS180 cells over the entire concentration range for all the herbal products investigated in this study. These in vitro pharmacokinetic interactions indicate the selected herbal products may affect indinavir’s bioavailability, but the clinical significance needs to be confirmed with in vivo studies before final conclusions can be made. / MSc (Pharmaceutics), North-West University, Potchefstroom Campus, 2015

Einleitung Die ständige Suche nach effektiveren und/oder weiteren botanischen Antibiotika im weiten Feld der geographischen Artenvielfalt macht den Stand der Forschung sehr unübersichtlich. Ziel dieser Arbeit ist es, durch Literaturrecherche eine Übersicht antimikrobiell wirksamer Pflanzen, Zubereitungen und Extrakte auf ausgewählte Bakterien der Mundhöhle aufzuzeigen. Material und Methoden Die Literaturrecherche erfolgte weltweit durch englische Schlüsselwörter in den elektronischen Datenbanken Cochrane Library, Pubmed / Medline, Embase und Google scholar für den Zeitraum bis einschließlich Dezember 2012. Ergebnisse Es wurden Veröffentlichungen über 735 Pflanzen gefunden, die auf ihre antimikrobielle Wirkung gegen folgende Mikroorganismen getestet wurden: Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, Fusobacterium nucleatum, Prevotella intermedia, Campylobacter rectus, Streptococcus mutans, Streptococcus mitis, Streptococcus oralis, Streptococcus sanguinis, Streptococcus gordonii. Gute antimikrobielle Wirkung zeigten Extrakte von 149 Pflanzen. In 87 klinischen Studien wurden Extrakte und Mixturen von ingesamt 61 Pflanzen untersucht, wovon nur 4 Studien keinen Effekt auf die klinischen Parameter hatten. Schlussfolgerung für die Klinik Pflanzenextrakte als neue potenzielle antimikrobielle Wirkstoffe in Prävention und Therapie von oralen Erkrankungen erforden noch weitere kontrollierte Studien in definierten Verfahren. / Introduction The constant search for more effective and / or other botanical antibiotics in the vast field of geographic diversity makes the state of research very confusing. The aim of this work is to show an overview of antimicrobial plants, preparations and extracts on selected bacteria of the oral cavity through literature. Material and Methods The literature search was carried worldwide by English keywords in the electronic databases Cochrane Library, PubMed / Medline, Embase and Google scholar for the period up to and including December 2012. Results Publications were found about 735 plants. They were tested for antimicrobial activity against the following microorganisms: Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, Fusobacterium nucleatum, Prevotella intermedia, Campylobacter rectus, Streptococcus mutans, Streptococcus mitis, Streptococcus oralis, Streptococcus sanguinis, Streptococcus gordonii. Extracts of 149 plants showed good antimicrobial effect. In 87 clinical studies, extracts and mixtures of a total of 61 plants were examined, of which only 4 studies had no effect on clinical parameters Conclusion for the clinic Require new potential plant extracts as antimicrobial agents in the prevention and treatment of oral diseases, further controlled studies in defined procedures

This study investigated the impact of three edaphic factors on the distribution of forest plants in Sweden. Based on 2657 plots with 22 common species, Canonical Correspondence Analysis (CCA) and Generalized-linear-model (GLM) were performed with pH measurements in the top layer of the soil, latitude and deciduous tree proportion as explanatory variables. Variation of the species occurrence could to a substantial degree be explained by pH, latitude and proportion of timber volume of deciduous tree species. Furthermore, the majority of species were affected by the studied environmental variables. Therefore, these factors have an important role in the ecological interactions in the forest. All species also showed broad pH-niches with many occurrences spread out within the species entire pH-range. Finally, the study relates to educational science through designing a meaningful excursion for secondary school when teaching ecology.

Selenium is a trace and essential element for good health but required only in very narrow range. Hence, determination of selenium in trace level in any matrix related with human health is important. A preconcentration method is performed to obtain a low detection limit for analyte. In this study, the methodology of cloud point extraction (CPE) was used as the preconcentration method for speciation of selenium in vitamin tablets. Non-ionic surfactant Triton X-114 and a fluorimetric ligand, 2,3- diaminonaphtalene (DAN) were used for the extraction of trace levels of organic and inorganic selenium species as a prior step to their determination by spectrofluorimetry. The aqueous solutions of nonionic and zwitterionic surfactant materials become cloudy when temperature reaches the cloud point temperature and analyte collapses with surface active material. The volume of surfactant rich phase is smaller than the solution volume and by this way high preconcentration factor was obtained. Optimization of the CPE parameters affecting complexation and phase separation was performed. Standard addition method was used in the quantitative measurements. Spectrofluorimetric determination of selenium was done using excitation and emission wavelegths of 380 nm end 570 nm respectively. The detection limit, established as 3s /slope where s is the standard deviation of 12 measurements of 0.02 mg/L Se-DAN complex after 10 fold preconcentration was 2.3 &micro / g/L. Accuracy of the method was checked using EnviroMat Waste Water, EU-L-2 as SRM and the result was in good agreement with certified value.Besides, selenium rich vegetables (dill, watercress herb and garlic) were grown in a pot at a controlled atmosphere.Selenium in plants (dill, watercress gerb and garlic), both control and enriched groups was determined by ICP-MS.

Orientador: Marlene Tiduko Ueta / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-10T03:20:32Z (GMT). No. of bitstreams: 1 Bernardes_HaydeeMariaSales_D.pdf: 1458843 bytes, checksum: c7f4fa3e8275d01a76b355a9371effc1 (MD5) Previous issue date: 2006 / Resumo: No presente estudo foi avaliado o efeito anti-helmíntico do extrato hidroalcóolico (EHA) de Chenopodium ambrosioides L. (Chenopodiaceae) e frações sobre Strongyloides venezuelensis (Brumpt, 1934). O EHA de C. ambrosioides foi obtido de folhas secas e moídas em solução de etanol:água (70:30) em sistema de extração ultra turrax. O extrato hidroalcóolico liofilizado (EHA) foi fracionado e analisado. Foram realizados testes para a determinação da concentração resposta em camundongos Swiss machos de 30 dias, infectados com S.venezuelensis e tratados, via oral, com as concentrações de 100mg Kg- 1/animal/dia, 250mg Kg-1/animal/dia e 400mg Kg-1/animal/dia durante cinco dias. Foram formados grupos de 10 animais para cada concentração e um grupo controle. Os animais foram infectados por injeção subcutânea com 1500 larvas e sacrificados no 6o d.p.i para contagem do número de ovos e de fêmeas. A concentração de 400mg Kg-1/animal/dia apresentou maior eficácia tanto para o número de ovos por grama de fezes (75,89 %) quanto para as fêmeas parasitas (86,31 %). Em outro experimento a concentração de 400mgKg-1/animal dia do EHA de C.ambrosioides foi comparada com o Tiabendazol (TBZ) na concentração de 50 mgKg-1/animal/dia em regime de tratamento pós e préinfecção sendo formados grupos de 10 animais para cada tratamento e droga. Nos tratamentos pré-infecção, os animais receberam TBZ ou EHA de C. ambrosioides durante cinco dias e foram infectados com 1500 larvas. Nos tratamentos pós-infecção, os animais foram infectados, tratados com TBZ ou EHA de C.ambrosioides 24h após infecção durante cinco dias. Em ambos os tratamentos os animais foram sacrificados no 6o d.p.i para a contagem de ovos e fêmeas. A concentração de 400mgKg-1/animal/dia apresentou eficácia de 99,14 % e 89,95 % para ovos e fêmeas, respectivamente quando avaliado o grupo tratado pré-infecção contra 79,60 % para ovos e 86,46 % para fêmeas parasitas, no grupo tratado pós-infecção. O TBZ apresentou eficácia de 39,91 % para o OPG e 89,54 % para fêmeas no grupo tratado pré-infecção e eficácia de 100 % tanto para ovos quanto para as fêmeas no regime de tratamento pós-infecção. O TBZ mostrou-se pouco eficiente como preventivo da infecção de camundongos por S. venezuelensis. O EHA de C. ambrosioides apresentou eficácia moderada para o número de fêmeas no tratamento pós-infecção. Após o fracionamento do EHA em seis frações, das quais três (Fr 4, Fr 5 e Fr 6) foram testadas em regime de tratamento pós e pré infecção na concentração de 250 mg Kg-1/animal/dia durante cinco dias. Foram formados grupos de 10 animais para cada fração e um grupo controle. A infecção e administração foram realizadas como descrito anteriormente. A fração 6 foi a que apresentou maior eficácia para ovos (94,51 %) e fêmeas (90,55 %) no tratamento pós-infecção. No tratamento pré-infecção, a Fr 5 foi a mais eficaz para os ovos (90,84 %) e para as fêmeas parasitas (67,28 %). Ficou demonstrada a presença de compostos fenólicos da classe dos flavonóides (por CCD) nas frações 5 e 6. A fração 6 apresentou-se mais rica nesses flavonóides semelhantes aos padrões de flavonóides testados. O fitol foi o composto majoritário detectado no EHA por CG-EM / Abstract: The present study the antihelmintic effect of the hidroalcholic extract (EHA) Chenopodium ambrosioides L. (Chenopodiaceae) and fractions obtained of dry column on Strongyloides venezuelensis (Brumpt, 1934) was evaluated The EHA of C. ambrosioides was obtained from dried and powered using ethanol:H2O solution (70:30). The extract was evaporated and liophilized, getting the hidroalcoholic crude extract. The EHA was partitioned in dry column using chloroform: methanol solution (90:10) and analyzed by TLC (Thin Layer Chromatography) and GC-MS (Gasous Cromatography Mass Espectometry). Tests for the determination of the concentration response had been carried out in Swiss male mice of 30 days infected with S. venezuelensis and treated with the concentrations to 100mg kg-1/animal/day, 250mg kg-1/animal/day and 400mg kg-1/animal/day during five days by intraesophageal intubation. Groups of 10 animals for each concentration and a control group were formed. The animals had been infected subcutaneous injection with 1500 larvae sacrificed in 6o d.p.i (day post-infectuion) for evaluation for the number of eggs and females. The concentration of 400mg kg-1/animal/dia presented greater in such a way effectiveness for the eggs (75.89 %) how much for the parasites females (86.31 %). In another experiment it was compared concentration of 400mgKg-1/animal/day of the EHA of C. ambrosioides with Thiabendazole (TBZ) in regimen of treatment post and preinfection being formed groups of 10 animals for each treatment and drugs. In the preinfection treatments, the animals had been treated with EHA of C. ambrosioides or TBZ during five days and infected. In the post-infection treatments, the animals had been infected, treated with TBZ or EHA of C. ambrosioides 24h after infection during five days. The animals had been sacrificed for quantification of eggs and females in the 6o d.p.i..The 400mgKg-1/animal/dia concentration presented effectiveness of 99.14 % and 89.95 % for the eggs and females respectively when evaluated the pre-infection treated group against 79.60 % to (eggs) and 86.46 % (females) in the group post-infection treated. The TBZ presented a effectiveness of 39.91 % for eggs and 89.54 % for the females in the preinfection treated group and effectiveness of 100 % for eggs how much for the females parasites in the regimen of post-infection treatment. The TBZ revealed little efficient as preventive of the infection of mice with S. venezuelensis. The EHA of C. ambrosioides presented moderate effectiveness to the number of female parasites in the treatment post infection. After the partition of the EHA six fractions had been gotten and three (Fraction 4, 5 Fraction 5 and Fraction 6 ) had been tested in regimen of post-infection and pre-infection in the 250 mg kg-1/animal/dia concentration during five days. Groups of 10 animals for each fraction had been formed and one control group. The infection and administration had been carried through as described previously. The fraction 6 presented greater effectiveness for the eggs (94.51 %) and parasite females (90.55 %) in the group post-infection treated. In the treatment pre-infection, the Fr 5 was the one that revealed more efficient for the eggs (90.84 %) and for the number of female parasites (67.28 %). It showed the presence of fenolics compounds of flavonols class in tehe fractions 5 and 6 (in TLC). The fraction 6 presented more rich in these compounds, same to used standarts. The phytol was the compound major detected in the GC-MS / Doutorado / Parasitologia / Doutor em Parasitologia

Submitted by Mario BC (mario@bc.ufrpe.br) on 2016-06-02T13:20:51Z No. of bitstreams: 1 Patricia Barbosa Lima.pdf: 4109614 bytes, checksum: 3b7b42d45a4e5399c06e4dca0fa7137f (MD5) / Made available in DSpace on 2016-06-02T13:20:51Z (GMT). No. of bitstreams: 1 Patricia Barbosa Lima.pdf: 4109614 bytes, checksum: 3b7b42d45a4e5399c06e4dca0fa7137f (MD5) Previous issue date: 2016-02-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Secondary forest areas in different successional stages are predominantly found in tropical rainforest areas, and can help with biodiversity maintenance. These forests show gradual changes in biotic and abiotic environment throughout the forest succession. The successional trajectory is well described for woody flora. Nevertheless, studies on herbaceous plants are still lagging. This study was divided into two manuscripts, whose objectives were to: 1) analyze herbaceous assembly in a 30 years chronosequence of sugar cane abandonment, and compare theses assemblade to mature forest sites, also considering environmental factors (chronosequence age, surrounding forest cover, understory light, and soil characteristics) that drive the herbs responses; and 2) understand how aliens herbaceous affect richness, and native forest herbs diversity of this chronosequence. In order to understand this, one sugar cane abandoned chronosequence was selected, containing 15 secondary forest sites (FS) (ages varying from 4 up to 30 years of abandonment), and 15 areas of mature forest (FM) in the Corredor Ecológico Pacatuba-Gargaú landscape, located inside of Paraíba Atlantic forest. In each site were established nine plots of 5x5m, in a total of 270 plots, which all herbs were registered. The plants were identified and posteriorly classified regarding their geographic origin. An NMDS was performed in order to verify difference in the floristic composition among FS and FM sites, as well as, an analysis of indicator species of those environments was performed. Generalized Linear Models (GLMs) were used to test: the impact of age areas, soil characteristics, availability of light, and surrounding forest cover on the structural characteristics of herbs in FS; and the impact of the more representative aliens herbs on native flora of FS. In a total, 42,966 individuals were registered (of this total 32,915 and 10,615 native and alien individuals, respectively), in 67 species (59 natives; 6 aliens herbs; 2 morphospecies; 66% and 18% of exclusive species in FS and FM, respectively). The density and the diversity of the herbs were significantly higher in FS than in FM, while the richness was lower in FM and the equability did not exhibit significantive difference. There was more proportion of native herbs than aliens herbs in both habitats. The floristic composition was distinct between FS and FM, also were observed 21 and 11 indicatives species of FS and FM, respectively. The sites age was positively related to richness and species diversity; however, negatively related to the herbs density. Successional progress influenced positively native richness throughout the chronosequence, and minimized negative impact of the only two invasive especies Digitaria insularis and Megathyrsus maximum on native’s species. Surrounding forest cover was also one of the mainly variants that negatively influenced richness and herbs density of the studied landscape. Finally, this study shows that despite the invasive species presence on the sugar cane abandoned chronosequence, the landscape Corredor Ecológico Pacatuba-Gargaú exhibits a dense, diverse, and rich flora of herbs (natives and alien), that are in agreement to the Intermediate Disturbance Hypothesis, and it is favored by the increment of biotic resistance associated to environmental changes along the successional progress. / Áreas de floresta secundária em diferentes estádios sucessionais predominam na região tropical úmida e podem auxiliar na manutenção da biodiversidade. Estas florestas apresentam uma gradativa mudança nos meios biótico e abiótico no decorrer da sucessão florestal. A trajetória sucessional está bem descrita para a flora lenhosa, todavia estudos sobre as plantas herbáceas continuam defasados. Este trabalho foi dividido em dois manuscritos, que tiveram os objetivos de: 1) analisar a assembleia de herbáceas em uma cronossequência de 30 anos de abandono canavieiro, e comparar essas assembleias com as de sítios de florestas maduras, considerando também fatores ambientais (idade da cronossequência, cobertura florestal circundante, luminosidade no sub-bosque e características edáficas) que direcionam as respostas das ervas; e 2) compreender como herbáceas exóticas afetam a riqueza e a densidade de ervas florestais nativas dessa cronossequência. Para isso, foram selecionadas uma cronossequência de canaviais abandonados contendo 15 sítios de florestas secundárias (FS) (com idades variando de 4 até 30 anos de abandono) e 15 áreas de floresta madura (FM) na paisagem do corredor Ecológico Pacatuba-Gargaú localizada dentro da floresta Atlântica da Paraíba. Em cada sítio foram estabelecidas nove parcelas de 5x5m, totalizando 270 parcelas, nas quais todas as ervas foram registradas. As plantas foram identificadas e posteriormente classificadas quanto à origem geográfica. Um NMDS foi realizado para verificar a diferença na composição florística entre os sítios de FS e FM, bem como, foi realizada uma análise de espécies indicadoras destes ambientes. Modelos Lineares Generalizados (GLMs) foram usados para testar: 1) o impacto da idade das áreas, das características de solo, da disponibilidade de luz e da cobertura florestal circundante sobre as características estruturais das ervas em FS; e 2) o impacto das ervas exóticas mais representativas sobre a flora nativas de FS. Registraram-se 42.966 indivíduos no total (sendo 32.915 e 10.615 indivíduos nativos e exóticos, respectivamente), em 67 espécies (59 nativas; seis exóticas; duas morfoespécies; 66% e 18% de espécies exclusivas em FS e FM, respectivamente). A densidade e a diversidade de ervas foram significativamente maiores em FS do que em FM, enquanto que a riqueza foi menor em FM e a equitabilidade não exibiu diferença significativa. Houve maior proporção de ervas nativas do que ervas exóticas em ambos os hábitats. A composição florística foi distinta entre FS e FM, e foram observados 21 e 11 espécies indicadoras de FS e FM, respectivamente. A idade dos sítios foi positivamente relacionada à riqueza e diversidade de espécies, mas negativamente relacionada com a densidade de ervas. O avanço na sucessão influenciou positivamente a riqueza de nativas ao longo da cronossequência e minimizou o impacto negativo das únicas espécies invasoras Digitaria insularis e Megathyrsus maximum sobre as nativas. E a cobertura florestal circundante foi também uma das principais variáveis que influenciou negativamente a riqueza e densidade de ervas da paisagem estudada. Por fim, este estudo mostrou que apesar de possuir espécies invasoras na cronossequência de abandono canavieiro, a paisagem do Corredor Ecológico Pacatuba-Gargaú exibe uma rica, densa e diversa flora de ervas (nativas e exóticas), que segue os pressupostos da Hipótese do Distúrbio Intermediário e que é favorecida pelo incremento da resistência biótica associada às mudanças ambientais ao longo do avanço sucessional.

Orientador: Helena Teixeira Godoy / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-15T07:26:27Z (GMT). No. of bitstreams: 1 Bizzotto_CarolinaSchaper_D.pdf: 1638844 bytes, checksum: 02d02a3b31cb8fd2bf5d15d5464fe34c (MD5) Previous issue date: 2010 / Resumo: A otimização simultânea de múltiplas respostas foi utilizada no desenvolvimento de um método por eletroforese capilar (EC) para a determinação de cafeína em café descafeinado. O método foi desenvolvido utilizando o planejamento composto central para otimizar a concentração de dodecilsulfato de sódio (SDS), a concentração de carbonato de sódio e a voltagem. Os experimentos foram conduzidos com uma amostra de café descafeínado, onde o resíduo de cafeína foi extraído com clorofórmio, ressuspenso em água e filtrado. As condições otimizadas foram encontradas pela avaliação dos efeitos de seis respostas: separação de interferentes, área, ruído, variação na linha de base, corrente e tempo de análise. Modelos de regressão lineares e quadráticos foram gerados para cada conjunto de respostas. Os modelos de regressão, coeficientes de correlação e a análise de componentes principais (PCA) foram usados na determinação das condições experimentais ótimas. Os melhores resultados foram obtidos usando-se um capilar de 50 mm x 48 cm, tampão contendo 10 mmol. L-1 de carbonato de sódio e 50 mmol. L-1 de SDS (pH 11,0), 15 kV, 25,0 ºC e detecção a 206 nm. Sob as condições otimizadas, a cafeína foi separada dos interferentes. O tempo de análise foi de 5,5 min. O método desenvolvido foi validado e comparado a um método por CLAE quanto à eficiência de separação, tempo de análise, custo por análise e volume de resíduos gerados. O método por EC foi então aplicado a amostras de café descafeinado torrado moído e instantâneo e amostras de bebida enérgética. A quantidade total de xantinas presentes nas bebidas chimarrão e tererê, a base de erva-mate (Ilex paraguariensis), também foi avaliada. Estas bebidas foram preparadas como são tradicionalmente consumidas. Os valores de cafeína das amostras analisadas tanto por EC quanto por CLAE não foram estatisticamente diferentes a 95% de confiança. A sensibilidade do método por CLAE foi 42 vezes maior que a do método por EC, porém este apresentou um tempo total de análise 30,4% menor. O volume de resíduos gerados foi 33 vezes maior no método por CLAE, e o custo em reagentes foi 76,5 vezes menor por EC. A vantagem mais importante do método por EC foi o uso de tampão aquoso econômico e ecológico no processo de separação. Com relação às amostras analisadas, sete amostras de café de quatro diferentes marcas apresentaram teor de cafeína acima do permitido pela legislação brasileira, e 76% das bebidas energéticas possuíam menos cafeína do que o valor informado no rótulo do produto. O teor de cafeína e teobromina variou nos diferentes tipos comerciais de erva-mate empregados no preparo das bebidas. Além disso, o tererê apresentou níveis de xantinas 2,5 vezes maior que o chimarrão / Abstract: Multiple response simultaneous optimization was used to develop a micellar electrokinetic chromatography (MECK) method for caffeine determination in decaffeinated coffee samples. The method was developed using a central composite design to optimize the concentration of sodium dodecylsulfate (SDS), sodium carbonate and voltage (V). The experiments were carried out using a sample of Brazilian decaffeinated coffee extracted with chloroform, which was subsequently recovered with water and then filtered. Optimized conditions were found by evaluating the effects of six responses: interferent separation, area, noise, baseline variation, current e analysis time. Each set of response values was regressed on the factor levels of the experimental design using linear and quadratic models. The regression models, correlation coefficients involving both factor levels and response values, and a principal component analysis (PCA) were used to determine the optimum experimental conditions. Successful results were obtained using a fused-silica capillary of 50 mm x 48 cm total length, buffer containing 10 mmol. L-1 of sodium carbonate and 50 mmol. L-1 of SDS (pH 11.0), voltage of 15 kV, temperature of 25.0 ºC, with detection at 206 nm. Under optimized conditions, caffeine was separated from the interferents. The analysis time was of 5.5 min. After validation, the capillary electrophoresis (CE) method was compared to a HPLC method regarding separation performance, quantification of caffeine in twenty samples, analysis time, costs per analysis and volume of generated residue. CE method was applied to decaffeinated instant and groundroasted coffee, and energy drinks. The total amount of xanthines in mate (Ilex paraguariensis) beverages, ¿chimarrao¿ and ¿terere¿ obtained in the same way as they are traditionally consumed, was also estimated using the CE method. Caffeine content of the samples analyzed with both CE and HPLC methods did not differ statistically at 95% confidence level. HPLC method sensitivity was 42 times greater than by CE method. In another hand, CE presents total analysis time 30.4% lower than HPLC. The volume of generated residues was 33 times greater in HPLC and the cost in reagents for CE was 76.5 times lower than for HPLC. The most important advantage of CE is the use of economical and ecological aqueous buffer in the separation process. Regarding samples analyzed, seven decaffeinated coffee samples of four different brands showed higher levels than the limit specified by Brazilian legislation and 76% of the energy drinks samples had caffeine content lower than the value informed to the consumer. Caffeine and theobromine levels varied in different commercial types of mate employed for the beverages preparation. Besides, ¿terere¿ presented quantities 2.5 times higher than the ¿chimarrao¿ beverage / Doutorado / Doutor em Ciência de Alimentos

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