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    Wyświetlanie 1-6 z 6
    Tytuł:
    Wybrane antybiotyki nukleozydowe
    Selected nucleoside antibiotics
    Autorzy:
    Samaszko-Fiertek, J.
    Dmochowska, B.
    Ślusarz, R.
    Madaj, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/171562.pdf
    Data publikacji:
    2017
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    antybiotyki nukleozydowe
    tunikamycyna
    mureidomycyna
    muramycyna
    kapuramycyna
    nucleoside antibiotics
    tunicamycin
    mureidomycin
    muramycin
    capuramycin
    Opis:
    Every year there has been a growing increase in infections caused by strains of bacteria resistant to multiple drugs. This prompts scientists to search for new antibiotics that would be able to fight these infections. New therapeutics used in medicine, which offer greater hopes are nucleoside antibiotics. They represent a large family of natural compounds exhibiting a variety of biological functions [1]. These include antifungal, antiviral, antibacterial, insecticides, immunosuppressants or anticancer properties. These broad-spectrum antibiotics can be divided into three main groups: • antibacterial nucleoside antibiotics, responsible for the inhibition of bacterial translocation of phospho-N-acetylpentapeptides, involved in the biosynthesis of peptidoglycan cell wall of bacteria; • antifungal nucleoside antibiotics, which role is to inhibit chitin synthase, or stopping construction of the cell wall of fungi; • antiviral antibiotics nucleoside, their mechanism of action is mainly based on blocking the biosynthesis of proteins by peptide inhibition transferase. In recent years much attention has been focused on the construction, mechanism of action and biosynthesis of antibiotics [1–3]. The development of genetic engineering has opened the way for combinatorial biosynthesis and obtaining new or hybrid compounds. In this work we would like to discuss some of bioactive naturally occurring nucleoside antibiotics, such as tunicamycin (Fig. 6) [19–22], mureidomycin (Fig. 8) [31–34], muramycin (Fig. 9) [36] or capuramycin (Fig. 10) [38].
    Źródło:
    Wiadomości Chemiczne; 2017, 71, 1-2; 15-32
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Regulacja aktywności katalitycznej rybozymów HDV oraz deoksyrybozymów za pomocą antybiotyków i jonów metali
    Regulation of the catalytic activity of HDV ribozymes and deoxyribozymes with antibiotics and metal ions
    Autorzy:
    Wrzesinski, J.
    Ciesiołka, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/171740.pdf
    Data publikacji:
    2018
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    antybiotyki
    rybozymy HDV
    deoksyrybozymy
    jony metali
    antibiotics
    HDV ribozymes
    deoxyribozymes
    metal ions
    Opis:
    This review article describes the results of a 15-year cooperation between the Department of RNA Biochemistry at the Institute of Bioorganic Chemistry, Polish Academy of Sciences in Poznań and the Medical Chemistry Team of the Faculty of Chemistry at the University of Wrocław, headed by Professor Małgorzata Jeżowska- -Bojczuk. A wide spectrum of antibiotics and other low molecular compounds and their complexes with Cu2+ ions have been tested as potential inhibitors of the HDV ribozyme catalytic reaction. Unexpectedly, it has been found that a number of compounds, depending on the conditions, exhibit inhibitory or stimulatory properties, i.e. they act as modulators of the RNA catalysis process. It was found that the effect of stimulation / inhibition of the catalytic activity of the HDV ribozyme is closely related to the degree of protonation of the antibiotics under study in given conditions. Their ability to inhibit catalysis also increases after binding the Cu2+ cation. In an environment with a higher pH, antibiotics usually stimulate the cleavage reaction, as at least some of their nitrogen centers are allowed to participate in the catalysis reaction, as proton acceptors / donors or a catalytic metal ion coordination site. During the study of one of the antibiotics, bacitracin, it was also observed that it exhibits nucleolytic properties with RNA and DNA molecules. The discovery of the hydrolytic properties of bacitracin extended the potential use of this antibiotic in antiviral therapy with the aim to destroy undesired nucleic acids in the cell. To search for DNAzymes catalyzing RNA hydrolysis, the in vitro selection method was used. In the selection experiment aimed at obtaining DNAzymes active in the presence of Cd2+ ions, variants belonging to the family of DNAzymes 8–17 previously described in the literature were obtained. Analysis of their properties showed that not only Cd2+ but also Zn2+ and Mn2+ ions support catalysis, therefore the site of catalytic metal ion coordination is not highly specific. The DNAzymes obtained in the second selection experiment showed an optimum of catalytic activity in the pH range of 4.0–4.5 and were inactive at a pH higher than 5.0. Interestingly, they do not require the presence of any divalent metal ions as cofactors in the catalysis reaction. The obtained results broaden the repertoire of DNAzymes which operate under non-physiological conditions and bring new information on the possible mechanisms of reactions catalyzed by nucleic acids.
    Źródło:
    Wiadomości Chemiczne; 2018, 72, 7-8; 397-415
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Antybiotyki peptydowe i ich kompleksy z jonami metali
    Peptide antibiotics and their complexes with metal ions
    Autorzy:
    Stokowa-Sołtys, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/171960.pdf
    Data publikacji:
    2018
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    antybiotyki peptydowe
    metaloantybiotyki
    kompleksy jonów metali
    peptide antibiotics
    metalloantibiotic
    metal ion complexes
    Opis:
    Metal ions are essential for numerous antibiotics. They play a crucial role in the mechanism of action and may be involved in specific interactions with cell membrane or target molecules, such as: proteins and nucleic acids. Due to the fact that complexes usually poses a higher positive charge than free ligands, they might interact more tightly with DNA and RNA molecules. However, complexes may also form during antimicrobial agents application, because a lot of them possess functional groups which can bind metal ions present in physiological fluids. Many recent studies support a hypothesis that drugs may alter the serum metal ions concentration. Moreover, it has been shown that numerous complexes with antibiotics can cause DNA degradation, e.g. bleomycin which form stable complexes with redox metal ions and split the nucleic acids chain via the free radicals mechanism. Therefore, it is widely used in cancer therapy.
    Źródło:
    Wiadomości Chemiczne; 2018, 72, 7-8; 497-522
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Biokoniugaty antybiotykow jonoforowych : cele, strategie syntezy i właściwości
    Bioconjugates of ionophore antibiotics : goals, synthesis strategies and properties
    Autorzy:
    Antoszczak, M.
    Kordylas, M.
    Huczyński, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/172178.pdf
    Data publikacji:
    2018
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    antybiotyki jonoforowe
    jonofory
    biokoniugacja
    hybrydy
    aktywność przeciwbakteryjna
    aktywność przeciwnowotworowa
    ionophore antibiotics
    ionophores
    bioconjugation
    hybrids
    antibacterial
    activity
    anticancer activity
    Opis:
    Polyether ionophore antibiotics (ionophores) represent a large group of naturally- occurring lipophilic compounds which are able to form complexes with the metal cations and transport them across the lipid membranes. This process disturbs the intercellular Na+/K+ concentration gradient and intracellular pH, and leads to the mitochondrial damages, cell swelling, vacuolization and finally to apoptosis process. For this reason, ionophores are commonly used in veterinary medicine as the non-hormonal growth-promoting as well as coccidiostatic agents. In this group particularly interesting are monensin and salinomycin (Fig. 1) because of their proved anti-tumour activity, including efficiency against multidrug- -resistant cancer cells and cancer stem cells of different origin. Improved synthetic derivatives of both polyether ionophores are thus of considerable current interest. Selective derivatization of these structures whose display multiple reactive functional groups and, in the case of salinomycin, a sensitive tricyclic spiroketal ring system is however non-trivial. Even so, semi-synthetic analogs reported to date includes i.a. selective derivatization of the carboxyl group, the three hydroxyl groups, the ketone group, the alkene, and epimerization of the characteristic tricyclic salinomycin unit (for more details see: M. Antoszczak, A. Huczyński, B. Brzezinski, Wiad. Chem., 2017, 71, 629). On the other hand, as part of the original program to develop innovatory anti- -cancer pro-drugs and prompted by the idea that cancer cells may be individually effectively killed by monensin and salinomycin, a very interesting direction of research is bioconjugation of these ionophores. In this context, our review article is focused on the possible role of hybrids of both ionophore antibiotics with other biologically active substances (natural amino acids, Cinchona alkaloids, flavonoids, nucleosides) in anti-bacterial and anti-cancer treatment, and gives an overview of their properties.
    Źródło:
    Wiadomości Chemiczne; 2018, 72, 1-2; 1-28
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Synteza i aktywność biologiczna pochodnych salinomycyny
    Synthesis and biological activity of salinomycin derivatives
    Autorzy:
    Antoszczak, M.
    Huczyński, A.
    Brzezinski, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/171728.pdf
    Data publikacji:
    2017
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    antybiotyki jonoforowe
    jonofory
    struktura molekularna
    aktywność przeciwbakteryjna
    aktywność przeciwnowotworowa
    ionophore antibiotics
    ionophores
    molecular structure
    antibacterial activity
    anticancer activity
    Opis:
    Polyether ionophore antibiotics (ionophores) represent a large group of naturally- occurring lipid-soluble compounds isolated from actinomycetes strains of Streptomyces genus. Ionophores are able to form complexes with the metal cations, especially sodium and potassium, and transport them across the lipid membranes according to electroneutral or electrogenic transport mechanism. This process disturbs the intercellular Na+/K+ concentration gradient and intracellular pH, leads to the mitochondrial injuries, cell swelling, vacuolization and finally to programmed cell death (apoptosis). For this reason, ionophore antibiotics found commercial use in veterinary medicine as coccidiostatic agents and non-hormonal growth promoters. In addition to the industrial use of ionophores, some of them effectively and selectively inhibit properties of different cancer cells as well as enhance the anti-cancer effects of radio- and/or chemotherapy. In this group, particularly interesting is salinomycin because of its potent anti-microbial and anti-cancer activity, including efficiency against multi-drug resistant cancer cells and cancer stem cells. A very interesting direction of research is the chemical modification of ionophore antibiotics, which can lead to obtaining various derivatives with better biological activity and lower toxicity than those of the starting substances. Because biological activity of ionophore antibiotics and their derivatives is strictly connected with the ability to form characteristic pseudocyclic structures around the complexed cations (host-guest complex), it is also important to establish the detailed information on these structures. In this context, our review article is focused on the possible role of salinomycin and its derivatives in anti-microbial as well as anti-cancer therapy, and gives an overview of the properties of this antibiotic.
    Źródło:
    Wiadomości Chemiczne; 2017, 71, 7-8; 629-661
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Antybiotyki fluorochinolonowe i ich modyfikacje strukturalne
    Fluoroquinolone antibiotics and their structural modifications
    Autorzy:
    Komarnicka, U. K.
    Walencik, P. K.
    Lesiów, M. K.
    Krupa, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/172433.pdf
    Data publikacji:
    2018
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    antybiotyki fluorochnolonowe
    modyfikacja strukturalna
    sparfloksacyna
    lomefloksacyna
    właściwości przeciwbakteryjne
    właściwości przeciwnowotworowe
    fluoroquinolone antibiotics
    complexes
    structural modifications
    sparfloxacin
    lomefloxacin
    antibacterial properties
    anticancer properties
    Opis:
    The quinolones are synthetic antibiotics derived from nalidixic acid. Chemical modification of basic structure (nalidixic acid) has led to the development of a group of various compounds currently used in medicine. This article discusses the generation of quinolones, mode of their action, and relationship between activity and structure of these antibiotics. The most common quinolones, lomefloxacin and sparfloxacin were discussed in details, also the therapeutic potential of newer agents was reviewed. Recently, understanding of how molecular modifications among quinolone core structure can affect antimicrobial and anticancer activities has progressed rapidly. In this paper we discussed few examples of fluoroquinolone structural modifications. It was proved that many organic and inorganic compounds derived from fluoroquinolones overcame bacterial drug-resistance. Furthermore, chemical modification improved fluoroquinolone’s anticancer activities.
    Źródło:
    Wiadomości Chemiczne; 2018, 72, 7-8; 543-561
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-6 z 6

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