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 in Prague, Faculty of Pharmacy in Hradec Králové Supervisor: Assoc. Prof. PharmD. Jan Zitko, PhD. Author: Marek Kerda Title of diploma thesis: Design, synthesis and biological evaluation of 2,3-disubstituted pyrazines This thesis deals with problem of tuberculosis. In a theoretical part are summarized information and knowledge about tuberculosis, nowadays epidemiology and drugs used in current treatment. There are also described drugs in the different stage of clinical trials and could be used for treatment of tuberculosis in the future. Searched information were used from accessible learning materials and in articles in online databases as Web of Science and PubMed. There are also summarized basic methods of computer design of new drugs. In practical part of this thesis was focus on novel inhibitor of prolyl-tRNA synthetase, which is based on structure of pyrazinamide. There was prepared in silico virtual library of pyrazine-based new potential ligands. Related docking to the structure of human prolyl t-RNA (pdb: 5VAD) and the bacterial version of this enzyme (pdb: 2J3M) and evaluation was performed in Molecular Operating Environment (Chemical Computing Group, Canada). From the results were predicted some of the relations between structure and activity. Virtual library of the...

Thesis (M.Sc. (Chemistry)) -- University of Limpopo, 2020 / In an attempt to synthesise quinoxaline-ferrocene compounds with antimycobacterial activity; a series of quinoxaline alkynyl derivatives were successfully synthesised from 3- (quinoxalin-3-yl)prop-2-yn-1-ol 86A and 3-(6-chloroquinoxalin-2-yl)prop-2-yn-1-ol 86B. In this series compounds 87A – B, 90A – B, and 93A – C were intermediates obtained in an effort to synthesise quinoxaline-ferrocene compounds. Treatment of either 86A or 86B with various acid chlorides afforded quinoxaline alkynyl ester derivatives 97A - 97B. Within this series, two quinoxaline-ferrocene compounds 3-(quinoxalin-3-yl)prop-2-ynyl ferrocetate 97A-iv and 3-(6-chloroquinoxalin-2-yl)prop-2-ynyl ferrocetate 97B-iv were successfully incorporated with ferrocenoyl chloride and obtained in 42 - 43% yield. The reactions of 3-chloroquinoxaline-2-carbonyl chloride 99 with ferrocenyl alcohol and ferrocenyl amine were unsuccessful. However, 3-chloroquinoxaline-2-carbonyl ester 100A - C and amide 101A - D derivatives with various alcohols and amines were obtained. The structures of all the compounds were confirmed by spectroscopic analysis (NMR, FT-IR and HRMS). The synthesised compounds were all evaluated for preliminary in-vitro antimycobacterial activity. The results obtained exhibited compound 90B with the highest activity against Mtb H37RV strain at MIC90 of 1.13 µM, followed by 90A and 87A exhibiting MIC90 of 4.55 and 6.47 µM, respectively. The quinoxaline alkynyl ester derivatives were found to exhibit poor to good activity. Within this series, three compounds were found to exhibit antimycobacterial activity at MIC90 ˂ 20 µM with compound 97A-ii showing the highest activity at MIC90 of 16.18 µM, followed by 97A-i and 97B-iii showing MIC90 of 18.05 and 19.36 µM, respectively. From the two quixonaline-ferrocene compounds, compound 97A iv was found to exhibit antimycobacterial activity at MIC90 of 39.90 µM. However, compound 97B-iv was found to be inactive. The 3-chloroquinoxaline-2-carbonyl ester 100A - C and amide 101A - D derivatives were found to be inactive. However, compound 99-C was found to exhibit antimycobacterial activity at MIC90 of 40.66 µM. Compounds 86A, 86C, 87A and 90A were evaluated for in-vitro antiproliferative activity against cancer cell lines. The results of antiproliferative activity showed that compounds 86A and 87A exhibited excellent activity against A549 lung cancer cell lines. Compound 87A was found to be the most active against A549 cell line showing 50% viability-inhibition at 25 µM / National Research Foundation (NRF)

Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Author: Martina Šimovičová Supervisors: Assoc. Prof. PharmDr. Jan Zitko, Ph.D.; Adjunct Prof. Paula Kiuru, Ph.D. Title of diploma thesis: Synthesis of aerothionin analogs as potential antimycobacterial agents Key words: antimycobacterial; tuberculosis; synthesis; aerothionin; bromotyrosines Drugs currently used for the treatment of tuberculosis are the result of studies carried out 50 or 60 years ago. With the constantly growing bacterial resistance to these pharmaceuticals grows also the importance of research for new antimycobacterially active compounds. The marine environment undoubtedly holds an enormous potential for discovering new leads for the development of antitubercular agents. One of these leads is a spirocyclic compound called aerothionin (1), which was found to be active against multidrug-resistant strains of Mycobacterium tuberculosis, as well as three non-tuberculosis mycobacteria (Figure 1). In addition, several spirocyclic structures (not only from marine origin) were discovered to affect on the M. tuberculosis in recent years, making this structure segment attractive for antitubercular research. Figure 1: Aerothionin (1) and general structure of the...

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...

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No. of bitstreams: 1 Tese - Daiane Martins.pdf: 4237333 bytes, checksum: e9cd7f69803566a70db4c62a6e1bb668 (MD5) Previous issue date: 2014-02-25 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / The species of Rubiaceae revealed great diversity of secondary metabolites, which are responsible for a range of biological activities. Among these species is Duroia macrophylla Huber, endemic to the Amazon Rainforest, popularly known as “cabeça-de-urubú, apuruí ou puruí-grande-da-mata”. The absence of studies of plants of the genus Duroia and the absence of chemical studies and biological activity to D. macrophylla, the aim of this work was to isolate the chemical constituents and evaluate the extracts and compounds isolated on activities: antioxidant, toxicity against Artemia salina, antibacterial, antimycobacterial and antitumor. The plant material was collected two times, dried, grounded and extracted with dichloromethane or hexane and methanol. The extracts were subjected to phytochemical screening by comparative thin layer chromatography and to determine specific telltale signs of chemical classes. The extracts were tested as antioxidant, cytotoxic, antibacterial, antimycobacterial and antitumor, to increase the chances of obtaining active molecules and/or prototypes of drugs. The isolated compounds were identified by spectroscopic methods (1H, 13C and two-dimensional NMR) and mass spectrometry and essayed as antimicrobial and antitumor. All extracts showed signs of terpenes and only the dichloromethane extracts of leaves and branches of the 1st collection did not reveal with DPPH. The methanol extracts of both collections showed aromatic compounds. The presence of alkaloids was detected only in extracts from the branches of the 2nd collection. There were isolated and identified four substances of the extracts of the 1st collection: two triterpenes from dichloromethane extract of the leaves (oleanolic acid and ursolic acid), one chalcone from methanol extract of the leaves (4,4'- dihydroxy-3'-chalcone) and a phenolic acid from methanol extract of the branches (mmethoxy- p-hydroxy-benzoic acid). Were identified of the extracts of the 2nd collection, eight monoterpene indole alkaloids: 10-methoxy-ajmalicine, 11-methoxy-ajmalicine, 11-methoxy- 3-isoajmalicine, 9-methoxy-3-isoajmalicine, 9-methoxy-19-epi-3-isoajmalicine, 10-methoxy- 19-epi-3-isoajmalicine, 10-methoxy-3-isorauniticine and 10-methoxy-rauniticine. All compounds isolated in this study were described for the first time in the genus Duroia. The methanol extracts from leaves and branches in both collections showed a good antioxidant activity. In cytotoxic assay against A. salina only the methanol extract of the leaves (2nd collection) presented toxicity at lethal concentration (LC50) of 120 mg/mL. The extracts showed bacteriostatic activity against the bacteria Klebsiella pneumoniae, Flavobacterium corumnare, Salmonella enteridis and Pseudomonas aeruginosa. Of the substances tested only oleanolic acid showed antibacterial activity against Nocardia brasiliensis and Serratia marcescens, with a MIC of 500 mg/mL. Extracts subjected to antimycobacterial bioassay, the dichloromethane extract of the leaves (1st collection) showed better results against all strains of Mycobacterium tuberculosis with an MIC of 6.25 mg/mL for INHr strain, 25 mg/mL for the strain RMPr and ≤ 6.25 mg/ml for H37Rv strain. Only the alkaloids 10-methoxy-3- isorauniticine, the mixture of 9-methoxy-3-isoajmalicine with 9-methoxy-19-epi-3- isoajmalicine, 10-methoxy-3-isorauniticine and 10-methoxy-rauniticine tested against M. tuberculosis (strain INHr) showed better results rather those obtained from crude extracts. The extracts and alkaloids showed low cytotoxic potential on neoplastic cell lines: HCT116 (human colorectal carcinoma), MCF-7 (breast carcinoma), SK -Mel-19 (human melanoma) and on the non-neoplastic line: MRC-5 (human lung fibroblast). Keywords: alkaloids, antioxidant activity, antimycobacterial activity. / As espécies pertencentes à família Rubiaceae revelaram grande diversidade de metabólitos secundários, os quais são responsáveis por uma gama de atividades biológicas. Entre estas espécies encontra-se Duroia macrophylla Huber, endêmica da Floresta Amazônica, conhecida popularmente como cabeça-de-urubú, apuruí ou puruí-grande-da-mata. A escassez de estudos de plantas do gênero Duroia e a ausência de estudos químicos e de atividade biológica para D. macrophylla, instigaram este trabalho, cujo o objetivo foi isolar os constituintes químicos e avaliar os extratos e substâncias isoladas quanto às atividades: antioxidante, toxicidade frente à Artemia salina, antibacteriana, antimicobacteriana e antitumoral. Foram realizadas duas coletas desta espécie, extraída com diclorometano (DCM) ou hexano (Hex) e metanol (MeOH). Os extratos foram testados como antioxidante, citotóxico, antibacteriano, antimicobacteriano e antitumoral, com intuito de ampliar as chances de obter moléculas ativas e/ou protótipos de fármacos. As substâncias isoladas foram identificadas por métodos espectroscópicos (RMN de 1H, de 13C e bidimensionais) e por espectrometria de massas e testadas como antimicobacteriana e antitumoral. Na prospecção fitoquimica todos os extratos apresentaram indícios de terpenos e apenas os extratos DCM de folhas e galhos da 1ª coleta não apresentaram capacidade antioxidante frente ao revelador DPPH. Os extratos MeOH de ambas as coletas apresentam compostos aromáticos. A presença de alcaloides foi detectada apenas nos extratos dos galhos da 2ª coleta. Foram isoladas e identificadas quatro substâncias dos extratos da 1ª coleta: dois triterpenos do extrato DCM das folhas (ácido oleanólico e ácido ursólico), uma chalcona do extrato MeOH das folhas (4,4’dihidroxi-3’-chalcona) e um ácido fenólico do extrato MeOH dos galhos (ácido m-metoxi-p-hidroxi-benzoico). Dos extratos da 2ª coleta foram identificados oito alcaloides indólicos monoterpênicos: 10-metoxi-ajmalicina, 11-metoxi-ajmalicina, 11-metoxi-3-isoajmalicina, 9-metoxi-19-epi-3-isoajmalicina, 9-metoxi- 3-isoajmalicina, 10-metoxi-19-epi-3-isoajmalicina, 10-metoxi-3-isorauniticina e 10-metoxirauniticina. Todas as substâncias isoladas neste estudo estão sendo descritas pela primeira vez no gênero Duroia. A atividade antioxidante dos extratos MeOH de folhas e galhos de ambas as coletas foi bastante significativa. No ensaio citotóxico frente A. salina apenas o extrato metanólico das folhas da 2ª coleta apresentou toxidade na concentração letal (CL50) de 120 μg/mL. Os extratos apresentaram atividade bacteriostática sobre as bactérias Klebsiella pneumoniae, Flavobacterium corumnare, Salmonella enteridis e Pseudomonas aeroginosa. Das substâncias testadas apenas o ácido oleanólico apresentou atividade antibacteriana frente à Nocardia brasiliensis e Serratia marcescens, com uma CIM de 500 μg/mL. Dos extratos submetidos ao bioensaio antimicobacteriano, o extrato DCM das folhas (1ª coleta) apresentou melhor resultado frente às três cepas de Mycobacterium tuberculosis, com uma CMI de 6,25 μg/mL para a cepa INHr, de 25 μg/mL para a cepa RMPr e ≤ 6,25 μg/mL para a cepa H37Rv. Os alcaloides 10-metoxi-ajmalicina, a mistura de 9-metoxi-3-isoajmalicina com 9-metoxi-19- epi-3-isoajmalicina, 10-metoxi-3-isorauniticina e 10-metoxi-19-epi-3-isoajmalicina foram ativos frente ao M. tuberculosis (cepa INHr). Os extratos e alcaloides apresentaram baixo potencial citotóxico sobre as linhagens de células neoplásicas: HCT116 (carcinoma colorretal humano), MCF-7 (carcinoma de mama), SK-Mel-19 (melanoma humano) e sobre a linhagem não neoplásica: MRC-5 (fibroblasto de pulmão humano).

Chemotherapy of tuberculosis (TB), a disease caused by Mycobacterium tuberculosis (M. tuberculosis), is successful against actively-growing bacilli but ineffective against dormant/persistent organisms, found mainly in a protective lipid-laden granuloma, possibly necessitating the use of lipophilic antibiotics. In vitro, these bacilli are encased in lipid-rich biofilms. In this study, the antimycobacterial activity of one such agent, clofazimine, and its nanoparticle formulation, have been investigated against Mycobacterium smegmatis (M. smegmatis), as a surrogate for M. tuberculosis, by determining the bacteriostatic and bactericidal activities of the native (NC) and spray-dried (SDC) preparations of this agent on planktonic and biofilm populations, as well as their effects on biofilm formation and its lipid compositions, specifically free mycolic acid (FM) content. Both preparations were comparable, being bacteriostatic for rapidly-proliferating bacilli, bactericidal for slow-growing, biofilm-producing sessile bacteria, but ineffective against non-replicating, biofilm-encased M. smegmatis organisms. However, similar studies in M. tuberculosis are required. / Dissertation (MSc)--University of Pretoria, 2013. / Immunology / Unrestricted

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...

(ENGLISH) Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Candidate: Sarah Basem Bouz Supervisor: PharmDr. Jan Zitko, Ph.D. Title of diploma thesis: Derivatives of quinoxaline-2-carboxylic acid as potential antimicrobial compounds Despite the presence of well-established treatment plan, tuberculosis remains the number one killer of infections according to WHO. One of the reasons behind this failure in eradicating this infection is drug resistance. This fact potentiates worldwide efforts to develop new antituberculars. As part of our long-term research on pyrazine derivatives, we prepared a series of N-substituted quinoxaline-2-carboxamides, refer to fig. below. Quinoxaline-2-carboxylic acid was activated by oxalyl chloride and reacted with different anilines or benzylamines in the presence of pyridine at room temperature, overnight with stirring, and then obtained crudes were purified with flash chromatography. Final products were evaluated for in vitro antimicrobial activities against six mycobacterial strains, eight fungal stems, along with four gram positive and four gram negative bacteria of clinical importance. The most promising compound among all with broad spectrum of antimycobacterial activity (MICMtbH37Ra = 3.91...