Charles University, Pharmaceutical Faculty in Hradec Králové Department: Department of Pharmaceutical Chemistry and Pharmaceutical analysis Candidate: Martina Čečetková Supervisor: PharmDr. Jan Zitko, Ph.D. Title of Diploma Thesis: Pyrazinamide derivatives as potential antimicrobial compounds Even in 21st century, tuberculosis still remains a serious and global health threat. Tuberculosis is one of the 10 most common causes of death, the most burdened are developing countries, but this disease infects up to 1/3 of population worldwide. Due to ineffective treatment of tuberculosis in developing countries, the prevalence of tuberculosis which does not respond to standard treatment is increasing. It is necessary to develop new drugs effective against multidrug-resistant tuberculosis and prevent further spread of the disease. The design of final structures is based on previously synthesized molecule 6- chloro-N-(4-(4-fluorophenyl)thiazol-2-yl)pyrazine-2-carboxamide, which structure comes from first line antitubercular pyrazinamide (PZA) and 4-arylthiazol-2-amine scaffold with formerly identified antimycobacterial activity. This starting compound exhibits high activity against M. tuberculosis described by MIC = 0,78 µg/mL and low cytotoxicity. The object of study was to determine effect of substitution...

Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Candidate: Lucie Kučerová Supervisor: doc. PharmDr. Jan Zitko, Ph.D. Consultant: PharmDr. Martin Juhás Title of diploma thesis: Design, synthesis and evaluation of pyrazinamide derivatives as potential antimicrobial compounds II Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis complex and is currently one of the most common causes of death from an infectious disease. Treatment of tuberculosis is long-term, combined and controlled to prevent resistance. Resistance is very serious and therefore treatment is always performed with more antituberculars at the same time. Finding new drugs and improving existing ones is a constant part of research. In the theoretical part I tried to summarize information about tuberculosis, its causative agent, diagnostics, possible prevention and treatment strategy. I have described the most commonly used antituberculars, especially the first- line antituberculars - pyrazinamide, from which the derivatives synthesized in my work are based. In the experimental part I described the procedures and reactions used for synthesis of the new compounds, which were formed by combining pyrazinamide with various amino acids. In this...

Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical chemistry and Pharmaceutical analysis Author: Jana Žecová Supervisor: PharmDr. Jan Zitko, Ph.D. Title of diploma thesis: Compounds combining pyrazinamide and 4-aminobenzoic acid fragments as potential antituberculars Tuberculosis is a severe infectious disease, which has been afflicting the human world population for centuries. It's figuring in the scale of the deadliest diseases as well as the occurring of strains resistant to therapy requires a serious approach to this problem and the research of new therapeutic means. Among the actual antituberculars figure two compounds, PZA and PAS. Pyrazinamide is a first line drug, and its derivatives are subject of the research in the Department of Pharmaceutical chemistry and Pharmaceutical analysis. Structurally similar to 4-aminobenzoic acid, PAS is a second line antitubercular, which is again actual in the therapy of resistant form of TBC. This diploma thesis treats about possibilities of the use of compounds combining fragments of PZA and 4-aminobenzoic acid as potential antituberculars. Furthermore, this thesis evaluates the influence of PAS fragment in the derivatives prepared with this antimycobacterial purpose. The theoretical part describes the actual state of...

COMPOUNDS COMBINING PYRAZINAMIDE AND P-AMINOSALICYLIC ACID FRAGMENTS AS POTENTIAL ANTITUBERCULARS II ŽÁK ONDŘEJ Department of Pharmaceutical Chemistry and Drug Analysis, Faculty of Pharmacy in Hradec Králové, Charles University, Czech Republic A series of new compounds combining pyrazinamide and p-aminobenzoic acid was prepared and in vitro tested for antimycobacterial activity against M. tuberculosis, M. avium, M. kansasii, M. aurum and M. smegmatis. Previously prepared 4-(5-chloropyrazine-2-carboxamido)-2-hydroxybenzoic acid (R1 = OH) exerted micromolar activity against M.tuberculosis and low in vitro cytotoxicity in HepG2 cells. Para-Aminosalicylic acid (PAS) has significant antitubercular properties based on its resemblance to p-aminobenzoic acid and interference with the folate pathway in mycobacteria. To assess the role of the PAS fragment, we designed and prepared derivatives with modified substitution on the phenyl ring (R1 ). Further modification was the exchange of 5-Cl on the pyrazine core for (alkyl)amino substituent (JZ-OZ), which was a successful modification in previous series. Final compounds were described by melting point, elementary analysis, IR spectroscopy and 1 H, 13 C NMR. Changing the PAS fragment, when we removed or replaced the OH-group at position 2, the antimycobacterial...

Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical chemistry and Pharmaceutical analysis Author: Petr Šlechta Supervisor: doc. PharmDr. Jan Zitko, Ph.D. Consultant: MSc. Ghada Basem Bouz, Ph.D. Title of diploma thesis: Derivatives combining the fragment of pyrazinamide and 4-aminosalicylic acid as antimycobacterial compounds According to WHO, tuberculosis (TB) is the leading cause of death from a single infectious organism worldwide and the number of cases with drug resistant TB is still increasing, creating the need for new antituberculotics. Therefore, we report design, synthesis and antimicrobial evaluation of a series of hybrid compounds combining different pyrazinamide derivates and p- aminosalicylic acid as potential antituberculotic agents. The compounds were prepared by mixing different pyrazinecarboxylic acids, after activation by 1,1'-carbonyldiimidazole, with p- aminosalicylic acid in dimethylsulfoxide as a solvent. Obtained compounds were in vitro tested for their antimycobacterial activity against M. tuberculosis H37Rv, M. tuberculosis H37Ra and four other mycobacterial strains. Prepared compounds were also in vitro screened for antibacterial, antifungal, and cytotoxic (HepG2) activity. Most compounds showed antimycobacterial activity in range of...

Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical chemistry and Pharmaceutical analysis Author: Petr Šlechta Supervisor: doc. PharmDr. Jan Zitko, Ph.D. Consultant: MSc. Ghada Basem Bouz, Ph.D. Title of diploma thesis: Derivatives combining the fragment of pyrazinamide and 4-aminosalicylic acid as antimycobacterial compounds According to WHO, tuberculosis (TB) is the leading cause of death from a single infectious organism worldwide and the number of cases with drug resistant TB is still increasing, creating the need for new antituberculotics. Therefore, we report design, synthesis and antimicrobial evaluation of a series of hybrid compounds combining different pyrazinamide derivates and p- aminosalicylic acid as potential antituberculotic agents. The compounds were prepared by mixing different pyrazinecarboxylic acids, after activation by 1,1'-carbonyldiimidazole, with p- aminosalicylic acid in dimethylsulfoxide as a solvent. Obtained compounds were in vitro tested for their antimycobacterial activity against M. tuberculosis H37Rv, M. tuberculosis H37Ra and four other mycobacterial strains. Prepared compounds were also in vitro screened for antibacterial, antifungal, and cytotoxic (HepG2) activity. Most compounds showed antimycobacterial activity in range of...

Die Mechanochemie findet zunehmend Verwendung für die Synthese neuer Verbindungen. Dennoch sind die beim Mahlen stattfindenden Prozesse weitestgehend unverstanden. Dahingehend wurde in dieser Arbeit eine Dreifachkopplung aus in situ Synchrotron-Röntgenbeugung, Raman-Spektroskopie und Thermographie entwickelt, um mechanochemische Reaktionen unter realistischen Bedingungen in Echtzeit zu verfolgen. Dadurch konnten tiefgreifende Einblicke in den Reaktionsverlauf und Temperaturverlauf beim Mahlen erhalten und neue metastabile Verbindungen isoliert werden. Für die Bildung pharmazeutischer Cokristalle diente Pyrazinamid als Modellsystem. Es konnten neue binäre und ternäre Verbindungen synthetisiert, detailliert charakterisiert und deren Kristallstruktur aufgeklärt werden. Die Abhängigkeit der Stabilität polymorpher Cokristalle von der Temperatur und den Synthesebedingungen konnte gezeigt werden. In Konkurrenzreaktionen konnten Trends hinsichtlich der bevorzugten Bildung eine bestimmten Cokristalls beobachtet werden. Mittels in situ Untersuchungen wurde der Einfluss zentraler Reaktionsparameter, wie die Mahlfrequenz, der Kugeldurchmesser, der eingesetzte Ausgangsstoff und die Zugabe von Lösungsmittel, auf die Induktions- und Reaktionszeit der Reaktion ermittelt. Basierend auf den gewonnenen Erkenntnissen konnte ein Diffusionsmechanismus für die mechanochemische Cokristallbildung abgeleitet werden. / Mechanochemistry is increasingly applied for the synthesis of new compounds. Still, the processes taking place during milling are far from being understood. In this thesis, a triple coupling of in situ synchrotron X-ray diffraction, Raman spectroscopy and thermography has been developed to follow mechanochemical reactions under realistic conditions in real time. This allowed deep insights into the reaction and temperature progression during milling and the isolation of new metastable compounds. For the formation of pharmaceutical cocrystals pyrazinamide served as a model system. New binary and ternary compounds were synthesized, characterized in detail and their crystal structure solved. The dependence of the stability of polymorphic cocrystals on temperature and synthesis conditions could be shown. In competitive reactions, trends regarding the preferred formation of a certain cocrystal have been observed. The influence of important reaction parameters, such as the milling frequency, the ball diameter, the starting material used and the addition of solvent, on the induction and reaction time of the reaction was determined by means of in situ investigations. Based on the gained knowledge, a diffusion mechanism for the mechanochemical cocrystal formation could be derived.