Wyniki wyszukiwania - BazTech

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Peptydy jako potencjalne ligandy wiążące jony metali przejściowych

Krupa K., Lesiów M. K., Kowalik-Jankowska T.

Wiadomości Chemiczne

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2018

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[Z] 72, 7-8

597--608

EN

Peptides are crucial ligands for transition metal ions and form complexes with them, that can have important biological activity. Many factors impact on the creation of complexes such as: protection of amine group from N-terminal or carboxylate group from C-terminals of the protein, the presence of noncoordinating and coordinating side chains in the peptide sequence, the number of histidyl residues and their location in the peptide chain. In complexes the metal ion can be bound bound by various donor atoms from amino acids residues (e.g. nitrogen, oxygen or sulphur). In general, the protection of N- or C-terminal groups influences the less stable formation of complexes. Stable complexes are created, if the free amine group from the N-terminal is involved in the coordination process. Peptides with noncoordinating side chains include alanine or glycine. Glycine complexes are more stable than these with alanine. Histidyl residue is the most effective amino acid residue in binding metal ions. The amine group of the lysyl residue, thiol from cysteine or carboxylate from aspartyl or glutamyl residues are also functional groups that coordinate metal ions. The coordination process is initiated by a group that anchors metal ion. A free amine group from N-terminus or imidazole nitrogen are the best examples of anchor groups. The metal ions can also be bound through amide nitrogens, after their forced deprotonation by the anchor group and formation of chelate rings. Peptides containing two or more histidyl residues exhibit high structural diversity in the complexes formation. In addition, these peptides can also form macrochelates and polynuclear complexes. The location of amino acid residues in the peptide chain (especially histydyl residue) also results in the thermodynamically stable formation of complexes.

2

Białka błony zewnętrznej fusobacterium nucleatum jako potencjalny czynnik promocji nowotworu jelita grubego

Lesiów M. K., Krupa K., Komarnicka U. K., Walencik P. K.

Wiadomości Chemiczne

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2018

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[Z] 72, 7-8

585--596

EN

Fusobacterium nucleatum is a Gram-negative, anaerobic bacterium located in an oral cavity. This bacterium can migrate with blood to the different part of the human body e.g colon. The studies suggest participation of Fn in a colorectal cancer promotion, but a particular mechanism of this disease is still unclear. Colorectal cancer leads to million of new death cases each year. It is third in the worldwide in terms of mortality. The predictions for the coming years are not optimistic. The statistics encourage researchers to know the details of the mechanism of colorectal cancer. It is suggest, that outer membrane proteins of Fn are responsible for development of this disease. Transition metal ions such as Cu(I), Cu(II), Fe(II) can coordinate to proteins and generate free radicals by Fenton reaction. Reactive oxygen species (ROS) destroy important biological macromolecules such as DNA, proteins or lipids and cause different diseases. The paper presents characteristics of Fn and its outer membrane proteins, description of copper(II) complexes and their ability to ROS generation.

3

Antybiotyki fluorochinolonowe i ich modyfikacje strukturalne

Komarnicka U. K., Walencik P. K., Lesiów M. K., Krupa K.

Wiadomości Chemiczne

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2018

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[Z] 72, 7-8

543--561

EN

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.