National Repository of Grey Literature 89 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Synthesis and evaluation of potential antitubercular agents based on nitro aromates
Delong, Jakub ; Krátký, Martin (advisor) ; Kučerová, Marta (referee)
The goal of the master's thesis was the synthesis and assessment of potential molecules against tuberculosis based on aromatic compounds containing nitro groups. The thesis reviews tuberculosis and its therapy, in the theoretical part, followed by well-know and new nitro group containing antibiotics. The experimental part reports multitep synthesis from parent compounds - substituted benzoic acid, pyruvic acid and variously substituted anilines, which were evaluated for their antimycobacterial activity. The core structure of the prepared compound molecules is N-phenyl-2-[2-(3,5- dinitrobenzoyl)hydrazinylidene]propanamide, which was variously substituted on the benzene ring of N-phenylpropanamide. In case of four compounds, one nitro group was switched to the trifluoromethyl group. Yields varied from 7 to 72 % and their minimum inhibitory concentrations (MIC) ranged from 4 to more than 1000 µmol/l. N-(4-Bromphenyl)-2-[2-(3,5- dinitrobenzoyl)hydrazinylidene]propanamide proved to be the most effective derivate. Key words Antibiotics, antimycobacterial activity, 3,5-dinitrobenzohydrazide, nitro group, synthesis, tuberculosis
Synthesis and investigation of potential antimicrobial compounds
Pokorná, Anežka ; Krátký, Martin (advisor) ; Zitko, Jan (referee)
One of the ways to alleviate the global problem of antibiotic resistance is, among other things, the synthesis and development of new antimicrobials. All compounds prepared in this work are based on the molecule 4-amino-1-benzylpiperidine or its isomer 4-(piperidin-1- ylmethyl)aniline. The parent molecule was chosen on the based on its previously reported activity. Thirteen imines were prepared using one-step synthesis by reacting the starting amine with the corresponding aldehyde. Two additional syntheses led to the amides by reaction of the starting molecule with the corresponding salicylic acid. The yields of the reactions ranged from 26 to 97 % for the imines and were 25 and 39 % for the amides. All compounds were prepared in sufficient quantity and purity to determine biological activity. All fifteen compounds were tested for their antibacterial activity against clinically relevant Gram-positive and Gram-negative strains. They were further tested for their antifungal activity, antimycobacterial aktivity, and their ability to inhibit the enzymes acetylcholinesterase and butyrylcholinesterase was also tested. The results of the evaluation showed that the amides were ineffective against microbes, but some imines showed excellent results. In general, the compounds were more active against...
Synthesis and evaluation of potential antimicrobial agents based on steroidal scaffold
Požárová, Pavla ; Krátký, Martin (advisor) ; Matouš, Petr (referee)
Antibiotic resistance represents a significant threat to humanity. To combat this trend, the development of new effective substances can be employed to potentially reverse its progression. Due to the broad range of biological activities exhibited by steroid structures, estrone was chosen as the starting material and was modified through various reactions. In total, fifteen new compounds were synthesized, which were tested for their antibacterial, antifungal, and antimycobacterial activities, and additionally for cholinesterases inhibition. The modification of estrone primarily involved two different approaches, resulting in the formation of hydrazones and esters. Twelve compounds were prepared through these steps. For the remaining three derivatives, changes in the starting materials or procedures were necessary. In the case of four compounds, it was necessary to synthesize one of the reactants. The yields ranged from 62% to 95% for hydrazones and from 8% to 54% for esters. The antibacterial activity was tested against four selected Gram-positive and Gram-negative strains. Antifungal activity was evaluated against four yeasts and filamentous fungi. Antimycobacterial activity was tested against five mycobacterial strains. All these methods utilized the microdilution broth method. The tested...
Synthesis and evaluation of potential drugs for neurodegenerative diseases
Foltýnová, Eva ; Krátký, Martin (advisor) ; Vinšová, Jarmila (referee)
The topic of this thesis is the synthesis of oxadiazole derivatives and their precursors as potential therapeutics for neurodegenerative diseases, and their evaluation primarily as potential inhibitors of cholinesterases (CHE). The theoretical part of this thesis focuses on Alzheimer's disease, particularly its pathophysiology, diagnosis, and treatment. It also discusses CHE inhibitors that are already clinically used, as well as new structures with potential for future clinical use. Additionally, it addresses the oxadiazole fragment, its chemical and biological properties. In the experimental work, derivatives of 1,3,4- and 1,2,4-oxadiazoles were synthesized, which differed not only in the type of oxadiazole but also in their substitution. These substances were prepared by the cyclization of precursors, which were also prepared and tested. For 1,3,4- oxadiazoles, besides their inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), their potential antimycobacterial, antibacterial, and antifungal activities were tested. For 1,2,4-oxadiazoles, so far, only their inhibitory activity against AChE and BuChE has been tested. A total of twenty-two substances were synthesized, and the yields of these syntheses ranged from 21-97%. The compound with the lowest IC50 value...
Synthesis and evaluation of novel disinfectant agents
Veselý, Jan ; Krátký, Martin (advisor) ; Vinšová, Jarmila (referee)
This diploma thesis deals with the synthesis and use of new quaternary ammonium salts (QACs). These substances have been commonly used for decades as disinfectants, antiseptics, antimicrobial additives, preservatives, and currently their decontamination potential using micellar catalysis is being investigated. The theoretical part contains information about the mechanism of action on individual types of microbes, an overview of physicochemical properties, especially solubility and determination of logP, micelle formation. Furthermore, microbial resistance and the mechanism of cross-resistance between QACs and antibiotics (ATB) are described here. The experimental part mainly deals with the synthesis of new QACs, which we expect to have an antimicrobial effect and the potential of creating a micellar microenvironment for micellar catalysis. The first series of reactions is focused on the preparation of three molecules of monoquaternary ammonium salts from the starting material benzylamine, to which two homologous aliphatic alkyl chains C8, C10 and C12 and a hydroxyethyl group are attached. This structure is a necessary carrier of the antimicrobial effect and the formation of micelles. All three molecules were successfully prepared. The second series of reactions is focused on the preparation of nine...
Synthesis and evaluation of potential antifungal agents
Straková, Jana ; Krátký, Martin (advisor) ; Novotná, Eva (referee)
Mycotic systemic infection is often very severe, whether due to patient immunodeficiency, the side effects of available antifungal agents, or clinical or drug resistance. Emphasis should therefore be placed on the timely determination of the correct diagnosis, appropriate indications of current drugs, and especially the development of new antifungal agents (ATM). The core of all synthesized compounds is the molecule of itaconic acid (IA) or its anhydride. The starting molecule was chosen based on its broad spectrum of biological activities, including antibacterial and antifungal activities. The aim was to create ten monoamides using a one-step synthesis of IA anhydride with the appropriate chlorinated aniline. These monoamides were then cyclized to form ten imides. The yields of the reactions to form the monoamides were high, with two exceptions (24% and 31%), and were generally above 80%. The yields of the reactions to form the imides were lower, ranging from 29% to 86%. The antimicrobial activity was tested using the broth microdilution method for all imides and most monoamides. All compounds were ineffective against gram-negative bacteria, and very low activity against gram-positive bacteria was shown by the compounds 1-(2,4,6-trichlorophenyl)-3-methylene-2,5-pyrrolidinedione,...
Studies on phthalocyanines and tetrapyrazinoporphyrazines - preparation, properties and potential biological applications.
Beranová, Michaela ; Miletín, Miroslav (advisor) ; Imramovský, Aleš (referee) ; Krátký, Martin (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Candidate: Mgr. Michaela Beranová Supervisor: doc. PharmDr. Miroslav Miletín, Ph.D. Title: Studies on phthalocyanines and tetrapyrazinoporphyrazines - preparation, properties and potential biological applications. Phthalocyanines (Pc) and their derivatives, tetrapyrazinoporphyrazines (TPyzPz), have been the subject of extensive research in various fields of science for almost a century. The macrocycle with its 18 π-electron conjugated double bond system carries very interesting photophysical and photochemical properties. These are high absorption and fluorescence emission in the near-infrared region (600 - 850 nm) and alternative ways of excited state energy release such as singlet oxygen production or fast intramolecular charge transfer. These characteristics and their extremely precise tuning due to their diverse but easy-to-prepare structures have made Pc and TPyzPz suitable candidates for applications in electrical engineering, materials industry, or medical disciplines. However, whether for photodynamic therapy of cancer and infectious diseases or the development of hybridization probes, they still exhibit undesirable properties that limit their potential applications....
Technology demonstrator of a four-stroke naturally aspirated spark-ignition engine
Chovanec, Stanislav ; Krátký, Martin (referee) ; Drápal, Lubomír (advisor)
Master’s thesis deals with design of single cylinder engine which is technology demonstrator of four cylinder naturally aspirated spark ignition engine Mazda Skyactiv-G. Outset of this thesis deals with construction of modern naturally aspirated engines and with comparison of their parameters. Computational part consists of forces in crank mechanism. These calculations are later used in FEM analysis of connecting rod.
Mobile application for 3D reconstruction
Krátký, Martin ; Janáková, Ilona (referee) ; Richter, Miloslav (advisor)
The aim of this master thesis is to create mobile application for spatial reconstruction. Thesis describes image processing methods suitable for solving this problem. Available platforms for creating mobile application are described. The parameters of the measured scenes are defined. A mobile application containing the described methods is created. The application is tested by reconstruction of objects in different conditions.

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See also: similar author names
1 Krátký, Marek
2 Krátký, Matouš
1 Krátký, Matěj
9 Krátký, Michal
1 Krátký, Milan
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