Mainz, Universiẗat, Diss., 2001.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.

Thesis--Catholic University of America. / Bibliography: p. 25-27.

Universiẗat, Diss., 2004--Bielefeld.

A hemoglobina (Hb) é uma fonte reconhecida de peptídeos com funções biológicas diversas. O fragmento 33-61 da cadeia α da Hb, isolado do trato gastrointestinal do carrapato Boophilus microplus, foi o primeiro a ser descrito com ação antimicrobiana. O seu análogo sintético amidado, Hb33-61a, mostrou-se ativo contra bactérias Gram-positivas e fungos [Fogaça et al. (1999) J. Biol. Chem. 274, 25330-4]. O estudo de análogos do Hb33-61 nas formas amidada e com carboxila livre revelou que a amidação provoca aumento significativo da atividade frente a Candida albicans. Por apresentar propriedades biológicas e estruturais idênticas às do Hb33-61a, o Hb40-61a pareceu ser a sua porção mÌnima ativa [Sforça et al. (2005) Biochemistry 44, 6440- 51; Machado et al. (2007) Biopolymers 88, 413-26]. Para comprovar tal sugestão, no presente trabalho, sintetizamos, purificamos e caracterizamos novos an·logos do Hb33-61a, bem como os avaliamos quanto às suas atividades frente a C. albicans e Micrococcus luteus. Os resultados confirmaram a sugestão apenas para a ação antifúngica. O análogo Hb40-61a também se mostrou ativo frente a C. albicans resistente a fluconazol. A sua atividade antifúngica se mostrou fortemente dependente da força iônica do meio. A sua baixa atividade hemolítica foi confirmada mesmo em meio de baixa força iônica. O peptídeo Hb40-61a não apresentou sinergismo com o fluconazol frente a C. albicans. A cinética de morte celular mostrou que ele mata a levedura de forma rápida. Portanto, esta hemocidina sintética pode apresentar valor comercial se a via de administração for tópica ou se o seu uso envolver meios de baixa força iônica. Além disso, ela é um modelo valioso para o estudo do mecanismo de ação de peptídeos antimicrobianos com características estruturais similares e pode servir de base para o desenho de novos agentes antibiôticos. / It is well known that hemoglobin (Hb) is a source of biologically active peptides. The fragment 33-61 of bovine hemoglobin α-chain, isolated from the gut contents of the tick Boophilus microplus, was the first identified with antimicrobial activity . Its amidated analogue, Hb33-61a, showed to be active against Gram-positive bacteria and fungi strains [FogaÁa et al. (1999) J. Biol. Chem. 274, 25330-4]. The study of a series of carboxyl-free and amidated synthetic analogues of Hb33-61 revealed that C-terminus amidation enhances the activity against Candida albicans. Since Hb33-61a and Hb40-61a presented identical biological and structural properties, it seemed that Hb40-61a was Hb33-61a minimal active motif [SforÁa et al. (2005) Biochemistry 44, 6440- To test this suggestion, in the present study 51; Machado et al. (2007) Biopolymers 88, 413-26]. we synthesized, purified and characterized Hb40-61a analogues and assayed them against C. albicans and Micrococcus luteus. The results confirmed the suggestion only for the antifungal activity. When tested against fluconazole-resistant C. albicans, Hb40-61a was also active. Its antifungal activity showed to be dependent on the ionic strength of the medium. Its low hemolytic activity was confirmed even under low ionic strength conditions. Hb40-61a had no synergic effect with fluconazole on C. albicans. In vitro time-kill assays demonstrated that Hb40-61a kills the yeast rapidly. Therefore, this synthetic hemocidin may be of commercial interest for topical application or other uses involving low ionic strength medium. Moreover, it can serve as a template for the study of the mechanism of action of structurally related antimicrobial peptides or for the design of novel antibiotic drugs.

A hemoglobina (Hb) é uma fonte reconhecida de peptídeos com funções biológicas diversas. O fragmento 33-61 da cadeia α da Hb, isolado do trato gastrointestinal do carrapato Boophilus microplus, foi o primeiro a ser descrito com ação antimicrobiana. O seu análogo sintético amidado, Hb33-61a, mostrou-se ativo contra bactérias Gram-positivas e fungos [Fogaça et al. (1999) J. Biol. Chem. 274, 25330-4]. O estudo de análogos do Hb33-61 nas formas amidada e com carboxila livre revelou que a amidação provoca aumento significativo da atividade frente a Candida albicans. Por apresentar propriedades biológicas e estruturais idênticas às do Hb33-61a, o Hb40-61a pareceu ser a sua porção mÌnima ativa [Sforça et al. (2005) Biochemistry 44, 6440- 51; Machado et al. (2007) Biopolymers 88, 413-26]. Para comprovar tal sugestão, no presente trabalho, sintetizamos, purificamos e caracterizamos novos an·logos do Hb33-61a, bem como os avaliamos quanto às suas atividades frente a C. albicans e Micrococcus luteus. Os resultados confirmaram a sugestão apenas para a ação antifúngica. O análogo Hb40-61a também se mostrou ativo frente a C. albicans resistente a fluconazol. A sua atividade antifúngica se mostrou fortemente dependente da força iônica do meio. A sua baixa atividade hemolítica foi confirmada mesmo em meio de baixa força iônica. O peptídeo Hb40-61a não apresentou sinergismo com o fluconazol frente a C. albicans. A cinética de morte celular mostrou que ele mata a levedura de forma rápida. Portanto, esta hemocidina sintética pode apresentar valor comercial se a via de administração for tópica ou se o seu uso envolver meios de baixa força iônica. Além disso, ela é um modelo valioso para o estudo do mecanismo de ação de peptídeos antimicrobianos com características estruturais similares e pode servir de base para o desenho de novos agentes antibiôticos. / It is well known that hemoglobin (Hb) is a source of biologically active peptides. The fragment 33-61 of bovine hemoglobin α-chain, isolated from the gut contents of the tick Boophilus microplus, was the first identified with antimicrobial activity . Its amidated analogue, Hb33-61a, showed to be active against Gram-positive bacteria and fungi strains [FogaÁa et al. (1999) J. Biol. Chem. 274, 25330-4]. The study of a series of carboxyl-free and amidated synthetic analogues of Hb33-61 revealed that C-terminus amidation enhances the activity against Candida albicans. Since Hb33-61a and Hb40-61a presented identical biological and structural properties, it seemed that Hb40-61a was Hb33-61a minimal active motif [SforÁa et al. (2005) Biochemistry 44, 6440- To test this suggestion, in the present study 51; Machado et al. (2007) Biopolymers 88, 413-26]. we synthesized, purified and characterized Hb40-61a analogues and assayed them against C. albicans and Micrococcus luteus. The results confirmed the suggestion only for the antifungal activity. When tested against fluconazole-resistant C. albicans, Hb40-61a was also active. Its antifungal activity showed to be dependent on the ionic strength of the medium. Its low hemolytic activity was confirmed even under low ionic strength conditions. Hb40-61a had no synergic effect with fluconazole on C. albicans. In vitro time-kill assays demonstrated that Hb40-61a kills the yeast rapidly. Therefore, this synthetic hemocidin may be of commercial interest for topical application or other uses involving low ionic strength medium. Moreover, it can serve as a template for the study of the mechanism of action of structurally related antimicrobial peptides or for the design of novel antibiotic drugs.

This master thesis is oriented on study antimicrobial effects extracts and macerates from cure Stevia rebaudiana Bertoni. Teoretical part describes basic information about plant Stevia, summary of health significant matters contained in Stevia and posobilities preparing extracts from Stevia. Antimicrobial effects extracts and macerates from cure Stevia were testing on food-borne bacteria (Bacillus cereus and Micrococcus luteus) and yeasts (Geotrichum candidum and Hansenula anomala). Microorganism, extracts and macerates were chosen on basis previous study (Study of antimicrobial effects Stevia Rebaudiana extracts, Eva Rakovská). For screening antimicrobial activity were determined the growth curves by using turbidimetrie for bacteria and direct treetment metod of cells number for yeasts. Antimicrobial effects were confirmed aplication with diffusion pit method on the agar ranges. From the results flow the testing extracts and macerates from stevia analysed antimicrobial effects. The best effect was demostrated on macerates and the most sensitive was bacteria Micrococcus luteus with the best inhibitoring effects.

Cannabis is the only plant which contains cannabinoids and thanks to these compounds it has enormous potential. This thesis deals with the analysis of technical hemp. Effects of cannabinoids and methods used for cannabis analysis are discussed in the theoretical part. The experimental part includes spectrophotometric characterization of cannabis, it´s antimicrobial effects and thin layer chromatography analysis. Three sorts of Cannabis sativa L. were analyzed, namely Finola, Fedora and Kompolti. Firstly, the content of polyphenols, flavonoids and antioxidant activity in prepared tinctures were determined. Moreover, antimicrobial test were performed using disk test and turbidity determination. Gram-positive and Gram-negative bacteria and yeast organism were tested. It was found that cannabis tinctures possess good antimicrobial effects. Some of them are comparable with synthetic antibiotics. Finally, thin layer chromatography enabled visualization of cannabinoids in prepared tinctures.