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Wyświetlanie 1-4 z 4
Tytuł:
Trans-1,2-diaminocykloheksan – niezwykła kariera outsidera
Trans-1,2-diaminocyclohexane – unprecedented outsider’s career
Autorzy:
Petryk, M.
Kwit, M.
Powiązania:
https://bibliotekanauki.pl/articles/171507.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
struktura
chiralność
konformacja
synteza asymetryczna
rozpoznanie molekularne
structure
chirality
conformation
asymmetric synthesis
molecular recognition
Opis:
An enantiopure trans-1,2-diaminocyclohexane is one of the most widely used chiral diamines in modern organic chemistry. This chiral building block, readily available from waste industrial products, emerges as a major figure in the field of asymmetric synthesis. The unique structural and conformational properties of trans-1,2-diaminocyclohexane make it very useful for the development of new synthetic strategies, taking advantage of its geometrical pre-organization. In this short article, we will highlight the utility of enantiomerically pure trans-1,2-diaminocyclohexane derivatives as broad-range chiral reagents and ligands for catalytic cycles. A brief overview of the aspects of applications in the field of molecular recognition will also be given.
Źródło:
Wiadomości Chemiczne; 2013, 67, 5-6; 393-442
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Skręty zwrotne w peptydach i białkach. Mimetyki skrętów zwrotnych. Część 1
Reverse turns in peptides and proteins. Reverse turns mimetics. Part 1
Autorzy:
Owińska, M.
Powiązania:
https://bibliotekanauki.pl/articles/171726.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
skręt zwrotny
wiązanie wodorowe
konformacja
kąt dwuścienny
reverse turn
hydrogen bond
conformation
dihedral angle
Opis:
The secondary structure of the proteins can be divided into α-helix, βsheet and reverse turns. A reverse turn is defined as a site where a polypeptide chain reverses its overall direction. It leads the chain to fold back on itself by almost 180°. Another condition for defining this motif is the amount of amino acid residues involved in forming the turn that can not be greater then six and polypeptide chain in this region can not be in helical conformation [1]. Turns are classified as: γ-turn, β-turn, α-turn and π-turn, which are formed by 3-, 4-, 5- and 6- amino acid residues, respectively. Turns defined as “closed” are stabilized by intramolecular hydrogen bonds between the main chain carbonyl group from the first residue and the main chain amide group from the last residue in the turn. This results in formation of 7-, 10-, 13- and 16-membered pseudo-rings, respectively (Fig. 1, Fig. 2). The other group of turns also stabilized by hydrogen bond, but conversely between the main chain amide group of the first residue and the carbonyl group of the last residue, are δ-turn (2-residues, 8-membered pseudo-ring) and ε-turn (3-residues, 11-membered pseudo-ring) (Fig. 2) [10–13]. These are seldom found in proteins. Turns are considered irregular structures due to the lack of clearly defined torsion angle preferences. because of that, each of the turn types can be further divided into several different subtypes (Table 1, 2 and 3) [1, 15, 31]. The “open” type structures are not stabilized by hydrogen bonds, but Cα-Cα distance between the first and the last residue in main chain is up to 10 A [10]. As turns can be found mostly on the surface of the proteins they play the important role in folding processes, thus enabling the formation of the tertiary structure [2]. The turns are also responsible for the interactions between proteins, recognition processes and ligand-receptor interactions [3–8]. In the following article, the classification and characterization of the turn types is described. The particular attention was given to the γ and β turns, as these are most commonly found in proteins structure.
Źródło:
Wiadomości Chemiczne; 2016, 70, 9-10; 598-611
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Peptydomimetyki i foldamery aromatyczne w chemii biologicznej
Peptidomimetics and aromatic foldamers in biological chemistry
Autorzy:
Ledwoń, Patrycja
Staśkiewicz, Agnieszka
Jewgiński, Michał
Latajka, Rafał
Powiązania:
https://bibliotekanauki.pl/articles/2200585.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
inhibitors of enzymes
peptidomimetics
conformation
cosmeceutics
aromatic foldamers
SAR
inhibitor enzymu
peptydomimetyki
konformacja
kosmeceutyki
foldamery aromatyczne
Opis:
The interests of the research group working under the supervision of professor Rafał Latajka at the Department of Bioorganic Chemistry at the Wrocław University of Science and Technology are focused on several projects in the field of biological chemistry. Regardless of whether a given project concerns – the synthesis and activity of new enzyme inhibitors, peptides, peptidomimetics, or aromatic foldamers – the thread of correlation between the structure and activity of the studied systems always plays a pivotal role. In this article we are presenting current projects in our research group.
Źródło:
Wiadomości Chemiczne; 2022, 76, 5-6; 349--363
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Konformacje pierścienia monosacharydowego
Monosaccharide ring conformations
Autorzy:
Stępień, Ł.
Liberek, B.
Powiązania:
https://bibliotekanauki.pl/articles/172490.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
konformacja
pseudorotacja
ekwatorialna orientacja
oddziaływania 1,3-diaksjalne
efekt anomeryczny
efekt allilowy
winylowy efekt anomeryczny
stała sprzężenia
conformation
pseudorotation
equatorial orientation
1,3-diaxial interactions
anomeric effect
allylic effect
vinylogous anomeric effect
coupling constant
Opis:
Conformational studies of the pyranose and furanose rings are important and have been carried out for years. Knowledge of the conformation of monosaccharide is essential for understanding its physical, chemical and biological properties. Additionally, conformation of the sugar ring plays a crucial role in the stereochemistry of the reaction in which it participates. This paper provides a basic knowledge concerning the conformational preferences of a monosaccharide ring. The pyranose ring conformations are defined with reference to a cyclohexane ring [1–3]. Factors influencing stability of the pyranose chair conformation are discussed: the 1,3-diaxial interactions [4–6] and anomeric effect [7–10]. It is shown how to estimate the relative stabilities of the two chair conformations on the basis of the Angyal destabilizing factors [11, 12]. It is also demonstrated how to use the NMR spectroscopy for conformational analysis [13–23]. Conformations of the unsaturated pyranose rings are defined and studied mainly on the glycals [24–29], the monosaccharides with a double bond between the C1 and C2 carbon atoms. Factors influencing stability of the unsaturated pyranose ring are disscused: the allylic effect [30] also named the vinylogous anomeric effect [31–34], and quasi 1,3-diaxial interactions [35, 36]. Finally, the furanose ring conformations and pseudorotational itinerary for a d-aldofuranose ring are presented [37]. Two parameters defining the furanose ring conformation are introduced: the amplitude of pseudorotation [38, 39], named also the maximum torsion angle [4] and pseudorotational phase angle [4]. The possible ways to study the conformation of the furanose ring are disscused [40–44].
Źródło:
Wiadomości Chemiczne; 2012, 66, 1-2; 67-92
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-4 z 4

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