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    Wyświetlanie 1-12 z 12
    Tytuł:
    Wpływ reszt ΔPhe na konformację łańcucha peptydowego
    Influence of ΔPhe residues on Conformation of peptide chain
    Autorzy:
    Ledwoń, Patrycja
    Staśkiewicz, Agnieszka
    Jewgiński, Michał
    Latajka, Rafał
    Powiązania:
    https://bibliotekanauki.pl/articles/171962.pdf
    Data publikacji:
    2020
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    dehydroaminokwasy
    dehydrofenyloalanina
    nośniki leków
    dehydroamino acids
    dehydrophenylalanine
    drug carriers
    Opis:
    In the past few years dehydropeptides have been highly investigated, mainly due to their biological activity: for instance, as antimicrobials or catalytic agents in some enzymes [1, 51-53]. In presented studies it was established that dehydrophenylalanine residue (ΔPhe) can be an interesting building block of various peptide chains, in order to control and modify a structure, conformation and function of the target molecule [3, 4, 5-7]. It was also pointed out that the length of a linker between dehydroamino acid residues (if two or more are present in a peptide chain) is a crucial factor in case of conformational dependence [23]. Short, one-residue spacers promote 310-helical structure, while longer ones increase the coexistence of 310-helical and α-helical conformers (Table 7). What is worth to notice, temperature or polarity of solvent can dramatically change the screw sense of obtained 310-helices (Table 11). Additionally, the screw sense can be altered by other variables, like chirality of C and N-terminus or dehydroamino acid isomer type (E or Z) [4-11]. Considering chain conformation, it can be disparate, depending on environment’s solid or liquid state (Table 7). Application of dehydropeptides is widely spread among assorted field of studies. As they can form a few self-assembled structures (e.g. nanotubes, nanovesicles or hydrogels), arise an opportunity of encapsulation of small drug molecules or trapping and releasing bioactive substances [47-49]. Sequences with incorporated dehydroamino acid residues were examined as a potential drug - interaction with negatively charged membrane of bacteria species is possible by virtue of positive polarization of peptide chain [51]. Part of the sequences exert an activity against E. coli, S. aureus, P. falciparum or highly dangerous MRSA, presenting versatile potential correlated with their secondary structure [50-53].
    Źródło:
    Wiadomości Chemiczne; 2020, 74, 1-2; 9-32
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Syntetyczne odpowiedniki fosfoenolopirogronianu, czyli jak naśladować biosyntezę kwasów ulozonowych
    Synthetic equivalents of phosphoenolpyruvate : how to imitate the biosynthesis of ulosonic acids
    Autorzy:
    Molenda, M. A.
    Powiązania:
    https://bibliotekanauki.pl/articles/172729.pdf
    Data publikacji:
    2014
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    reakcja aldolowa
    równoważnik pirogronianu
    kwasy ulozonowe
    aldol reaction
    pyruvate unit
    ulosonic acids
    Opis:
    Ulosonic acids are key intermediated in many important biochemical pathways. One of them is DAH, which takes part in the shikimic acid pathway, as precursor in aromatic amino acids biosynthesis [1]. Another interesting compound is KDN isolated from rainbow trout egg [2], where it is responsible for the protection of the embryo in the early stages of embryonic development [3]. In the nature ulosonic acids are synthesized from phosphorylated sugar aldehydes and phosphoenolpyruvate in enzymatic aldol reaction. Mimic of enzymatic catalysis by asymmetric direct aldol reaction is one of the challenges of modern organic synthesis. Unfortunately, installation of the pyruvate unit in laboratory conditions is quite problematic. The aim of this short review was to present synthetic equivalents of phosphoenolpyruvate, which over the years become more and more similar to the biosynthesis of ulosonic acids in living cells. The first applied pyruvic acid unit was 2-acethylthiazole used as stoichiometric lithium enolate in aldol addition [9]. Next, the same research group used the phosphine derivative of 2-acethylthiazole in Wittig olefination of sugar aldehydes with subsequent stereoselective syn Michael addition of the benzyl oxide anion. Another puryvate equivalent is dimethyl acetal of pyruvic aldehyde successfully used in organocatalytic [12] and metalorganocatalytic [14] direct aldol reactions. Nowadays sterically hindered aromatic ester of pyruvic acid is probably the best puryvate unit. This ester was successfully used as aldol reaction donor in synthesis of two 3-deoxy-2-ulosonic acids – KDG and KDO [18]. Aryl pyruvate reacts with aldehydes to give aldol product with high efficiency and good diastereoselectivity in reaction catalyzed by chiral tertiary amines represented by Cinchona alkaloids. Chiral sugar aldehydes and pyruvate ester, are the building blocks that famously mimic the biological precursors of ulosonic acids.
    Źródło:
    Wiadomości Chemiczne; 2014, 68, 9-10; 873-896
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Chemia bioortogonalna – użyteczne narzędzie badania procesów wewnątrzkomórkowych
    Bioortogonal chemistry - a useful tool for studying intercellular processes
    Autorzy:
    Latos, Krystian
    Powiązania:
    https://bibliotekanauki.pl/articles/2200602.pdf
    Data publikacji:
    2022
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    chemia bioortogonalna
    bioortogonalna ligacja
    kwasy nukleinowe
    białka
    sacharydy
    bioorthogonal chemistry
    bioorthogonal ligation
    nucleic acids
    proteins
    saccharides
    Opis:
    Bioorthogonal chemistry is a rapidly developing field of science operating on the border of chemistry and biology. Its initial goal was to study metabolism and imaging using fluorescently labelled compounds. Due to recent advances, bioorthogonal chemistry can also be used to engineer therapeutic bioconjugates. By using a combination of bioconjugation and advanced omics techniques, it is possible to study and modify complex interactions inside living cells. In the relatively short time since its introduction, bioorthogonal chemistry has found many applications. In nucleic acid research, it is used for labelling, e.g. with biotin, to facilitate detection, immobilization, and purification. Additionally, thanks to the use of fluorescent nucleoside analogues, it can be used to study the interaction and dynamics of nucleic acids. For the study of proteins, bioorthogonal chemistry is an invaluable tool for studying conformation, as well as intramolecular and intermolecular interactions. Using techniques such as PET and FRET it is possible to take a closer look at the structure of proteins, which has a significant impact on their functionality. By using biarsenical dyes, interactions between proteins are tracked. This is used in the study of protein aggregation in diseases such as Alzheimer's, Huntington's, and prion diseases. Thanks to this, it becomes possible to understand the mechanism and pathology of these diseases. In biosensing, the elements of bioorthogonal chemistry have been used in a variety of tests and imaging methods. In the end, methods for testing glycan are presented. The advantage of bioorthogonal methods is that they allow labelling on the whole cell or lysate. This application in glycoproteomics is extremely important due to the fact that changes in glycosylation occur during disease states.
    Źródło:
    Wiadomości Chemiczne; 2022, 76, 1-2; 79-95
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Receptory molekularne. Od cząsteczki receptora do funkcjonalnego materiału
    Molecular receptors. From receptor molecules to functional materials
    Autorzy:
    Schroeder, G.
    Powiązania:
    https://bibliotekanauki.pl/articles/171943.pdf
    Data publikacji:
    2011
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    receptory molekularne
    chemia materiałowa
    funkcjonalizowane materiały
    kwasy boronowe
    terpirydyna
    molecular receptor
    functionalized materials
    material chemistry
    boronic acids
    terpyridine
    Opis:
    The getting knowledge of the methods of chemical compounds synthesis on the planned construction site, both in terms of arrangement of atoms and functional groups, as well as spatial structure, allowed to obtain a number of new molecular receptor systems that are capable to creating host-guest complexes. The paper will present the way of the proceedings from molecular receptor to new material with this receptor, so in other words from individual molecules to the new material with specific and previously planned properties. This process is presented for two types of molecules: aryloboronic acids and terpyridine. The ability for rapid and reversible formation of boronic acids, esters of 1,2- and 1,3-diols resulted in that these compounds were used for the synthesis of sugar receptors and consequently to build the new generation of the sensors of sugars. 2,2’:6,2’-Terpyridine is ligand, that in solution forms complexes with most transition metal ions. This compound is used for the synthesis of functional polymers, dendrymers and fluorescent sensors of ions. The presentation of the applicability of molecular receptors in the preparation of new functional materials promotes the new approach to the work of chemists. The basic research in which we define the properties of individual molecules and molecular receptors can be the beginning of the application of these compounds in the material chemistry. Additionally it can lead to the synthesis of the new materials with the specific properties or the selective construction of the measuring systems. The process from the molecule that is characterized by well-studied properties to modern material chemistry is limited only by the imagination of chemists and by the demand for new organic materials in the industry and by the new generation of the selective measurement systems.
    Źródło:
    Wiadomości Chemiczne; 2011, 65, 11-12; 1021-1053
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Substancje biologicznie aktywne w winie
    Bioactive compounds in wine
    Autorzy:
    Małyszko, J.
    Karbarz, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/172595.pdf
    Data publikacji:
    2012
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    aktywność antyoksydacyjna
    flawonoidy
    kwas fenolowy
    melatonina
    resweratrol
    wino czerwone
    antioxidant activity
    flavonoids
    melatonin
    phenolic acids
    red wine
    resveratrol
    Opis:
    Wines are the subject of an increasing number of investigations. The benefits of red wine became widely recognized after the observation of “French paradox” [8–10]. It has been found that there is a low mortality rate from ischemic heart disease among French people despite their high consumption of saturated fatty acids and the prevalence of other risk factors. The health-protective properties of wine are attributed to their antioxidant activity, i.e. the capability to scavenge reactive oxygen species, ROS . An imbalance between antioxidants and oxygen species results in oxidative stress leading to cellular damage. The phenolic compounds present in wine show beneficial physiological properties including protection against coronary heart disease, as well as anti-inflammatory and anti-carcinogenic activity. Most of the beneficial effects of wine are attributed to the presence of flavonoids, resveratrol, phenolic acids and other antioxidants. This paper reviews the significance of different compounds present in wine and their effect on human health. Chapter 1 focuses on flavonoids: flavonols, flavan-3-ols and anthocyanidins (Fig. 1) [14–29]. This class of compounds can exist both in a simple form, as aglycones, and bounded with sugars, as glycosides. The presence of phenolic hydroxyl group in these compounds is essential for their antioxidant activity and enables to scavenge free radicals in vivo. Chapter 2 describes chemical and physicochemical properties of resveratrol (Fig. 2) [30-41] which is the main antioxidant in wine. Moreover, this compound has been shown to inhibit the oxidation of low density lipoproteins and the aggregation of platelets [44-47]. Resveratrol also exhibits anti-inflammatory and anticancer properties [48, 49]. Chapter 3 reveals that wines are also a good source of other antioxidants [50–55] as phenolic acids (Fig. 3), tyrosol and hydroxytyrosol (Fig. 4), and also melatonin (Fig. 5). Unfortunately, some wines can include mycotoxins, mainly ochratoxin A [59, 60] (Fig. 6), which is produced by the phytopatogenic fungi, Aspergillus carbonarius. All types of red wine contain different amounts of ethanol and phenolic antioxidants, and therefore it is probable that the cardioprotective effect of red wine is caused by both these kinds of components [57–58]. Epidemiological observations, clinical and experimental in vitro research prove that regular and moderate intake of wine, particularly red wine, reduces cardiovascular morbidity and mortality [66–70].
    Źródło:
    Wiadomości Chemiczne; 2012, 66, 5-6; 563-579
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Oligonukleotydy DNA jako warstwy receptorowe sensorów elektrochemicznych
    DNA oligonucleotides as receptor layers of electrochemical sensors
    Autorzy:
    Górski, Ł.
    Ziółkowski, R.
    Bala, A.
    Jarczewska, M.
    Malinowska, E.
    Powiązania:
    https://bibliotekanauki.pl/articles/171556.pdf
    Data publikacji:
    2015
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    biosensor
    metale ciężkie
    kwasy nukleinowe
    samoorganizujące się monowarstwy
    woltamperometria
    znaczniki redoks
    biosensors
    heavy metals
    nucleic acids
    self-assembled monolayers
    voltammetry
    redox indicators
    Opis:
    The need for elaboration of analytical devices of small dimensions and the accessibility of novel nanomaterials caused the increase in the number of publications referring to the development of biosensors. DNA-based biosensors are of special interest and they were primarily used for the determination of a specific sequence which is crucial in the detection of cancer, genetic mutations, pathogens, as well as analysis of modified food. Interestingly, they could be also applied for the detection of other analytes including heavy metal ions, especially in connection with electrochemical techniques. It should be noted that the design of DNA biosensor concerns not only the development of transducer, but also careful preparation of sensing layer and the choice of the method of analytical signal generation. Selectivity is one of the essential parameter of the biosensor that determines its utility, particularly in real samples of complex matrices. In case of DNA sensors dedicated for the detection of complementary sequence, high selectivity is provided by the hybridization process. A pronounced specificity of sensing layer-analyte interaction can be also achieved with the use of functional nucleic acids - aptamers, which change their conformation upon binding an analyte. Herein, DNA-modified electrodes were firstly used for the detection of uranyl ions, as they exhibit high affinity towards phosphate moieties of nuclec acids. It was shown that UO2 2+ interacts with sensing layer independently from the chosen oligonucleotide sequence. Moreover, the influence of Pb2+ was reduced by elimination of adenine, which strongly interacts with lead ions. Another oligonucleotide-based sensor was developed for detection of mercury ions. The results indicate that Hg2+ concentration can be determined only with the use of sequence containing 100% thymine residues. Oligonucleotide-based sensor with receptor layer containing aptamers was elaborated for the detection of Pb2+ ions. In the presence of lead cations, an aptamer probe forms a G-quadruplex structure, a proposed biosensor could be characterized with selectivity towards Pb2+ The performance of DNA-based sensors for UO2 2+, Hg2+ and Pb2+ ions was optimized and addressed the choice of the manner of analytical signal generation, the influence of electrode modification with blocking agent, sensitivity dependence on the oligonucleotide sequence and the possibility of regeneration of sensing layer. Finally, the utility of proposed DNA sensors was tested by analysis in real samples.
    Źródło:
    Wiadomości Chemiczne; 2015, 69, 5-6; 325-336
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Estry kwasów tłuszczowych glicydolu oraz estry kwasów tłuszczowych mono-3-chloropropan-1,2-diolu : nowe zanieczyszczenia w olejach jadalnych
    Glycidyl fatty acid esters and mono-3-chloropropane-1,2-diol fatty acid esters : new contamination in edible oils
    Autorzy:
    Aniołowska, M.
    Kita, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/172657.pdf
    Data publikacji:
    2014
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    estry kwasów tłuszczowych
    3-MCPD estry kwasów tłuszczowych
    glicydylowe estry kwasów tłuszczowych
    oleje jadalne
    3-MCPD fatty acid esters
    glycidyl fatty acids esters
    edible oils
    Opis:
    The aim of the review was to characterize and describe the physicochemical properties and methods for the determination of two types of compounds: 3-monochloropropane- 1,2-diol fatty acids esters (3-MCPD esters) and glycidyl fatty acids esters (GE) - new contaminants of food products, including vegetable fats. This paper describes their structure, several possible mechanisms of reactions occurring during the refining of edible oils, leading to an increase of their content in the final product. It is suggested that these compounds are formed from acylglycerols, under the influence of high temperature [9]. The emphasis was put on the toxicity of the products of their deesterification-free 3-monochloropropane-1,2-diol (3-MCPD) and glycidol. Glycidol is genotoxic and has an effect on gene mutations and unscheduled DNA synthesis [17]. 3-MCPD is defined by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) as a genotoxic carcinogen [6, 19]. There are three transformation tracks leading to increased levels of 3-MCPD in foods: from 3-MCPD esters, GE and glycidol [14, 15]. The content of 3-MCPD esters and GE in food products was characterized and different processes involving their synthesis were described. Ways of reduction in food products regarding the aspects of raw materials as well as technology were discussed. Among refined vegetable oils, the largest quantities of 3-MCPD esters and GE were found in palm, corn and coconut oils [6, 25]. Finally, the direct and indirect methods of their determination in oils were described. There are new publications reporting on successive improvements of the existing methods for determination of 3-MCPD and its mono- and di-esters, as well as GE in edible oils [42, 43]. Unfortunately, there is still no universal determination method, which would be simple, affordable and accessible for a wider group, such as food producers, that would improve consumer safety.
    Źródło:
    Wiadomości Chemiczne; 2014, 68, 7-8; 701-717
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Rozdzielenie mieszanin racemicznych za pomocą krystalizacji. Część 2, Rozdzielenie racematów z utworzeniem diastereoizomerycznych soli
    Separation of the racemic mixtures by crystallization. Part 2, Resolution by formation of diastereomeric salts
    Autorzy:
    Kołodziejska, R.
    Studzińska, R.
    Kopkowska, E.
    Karczmarska-Wódzka, A.
    Augustyńska, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/171666.pdf
    Data publikacji:
    2015
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    krystalizacja
    mieszanina racemiczna
    rozdzielenie racemicznych amin
    rozdzielenie racemicznych kwasów
    diastereoizomeryczne sole
    crystallization
    racemic mixture
    resolution of racemic mixture
    resolution of rac-amines
    resolution of rac-acids
    diastereoisomeric salts
    Opis:
    The enantioseparation of a racemate through diastereomeric salt formation with a resolving agent is one of the most attractive methods for obtaining an enantiopure compound, with advantages such as its simplicity in operation, recyclability of the chiral source, and applicability on an industrial scale. In this method the enantiomers are converted into a diastereomeric salt pair by reaction with a single enantiomer of resolving agent. The diastereomers are then separated by crystallization taking advantage of the different solubility of the two compounds [1–3]. The formation of diastereomers, to be separated afterward, usually consists of salt formation with a resolving agent of opposite acide-base character (Scheme 1, 9). In this process, the molecules of opposite character (amine and acid) recognize each other by various interactions on the basis of their molecular structures and functional groups [3]. Using this method can be obtained a series of enantiomerically pure amines (Scheme 2–8) [4–26] and acids (Scheme 10–17) [27–41] which may be valuable substrates for asymmetric synthesis. The conditions for enantioseparation play an important role. On the efficiency of the enantioseparation has an effect the resolving agent, nature of the solvent or just its dielectric constant and the character and amount of some supplementary additives.
    Źródło:
    Wiadomości Chemiczne; 2015, 69, 1-2; 89-110
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Zastosowanie soli chinoliniowych i pirydyniowych do oznaczania wybranych związków siarki w próbkach biologicznych
    Application of quinolinium and pyridinium salts for determination of selected sulfur compounds in biological samples
    Autorzy:
    Furmaniak, P.
    Wyszczelska-Rokiel, M.
    Kubalczyk, P.
    Głowacki, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/171524.pdf
    Data publikacji:
    2014
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    sole pirydyniowe
    sole chinoliniowe
    aminokwasy tiolowe
    derywatyzacja chemiczna
    chromatografia cieczowa
    wysokosprawna chromatografia cieczowa
    elektroforeza kapilarna
    pyridinium salts
    quinolinium salts
    thiol amino acids
    chemical derivatization
    high performance liquid chromatography
    capillary electrophoresis
    Opis:
    Quinolinium and pyridinium salts belong to the group of onium compounds and are widely used in organic, structural and analytical chemistry. Their synthesis is mainly based on quaternization of the nitrogen atom in a heterocyclic ring [4, 13, 23]. In analytical chemistry quinolinium and pyridinium salts such as 2-chloro-1-methylquinolinium tetrafluoroborate (CMQT) or 1-benzyl-2-chloropyridinium bromide (BCPB) perform very well as thiol specific derivatization reagents in terms of derivatization reaction velocity, stability, chromatographic properties of the derivatives, and thus, amenability to automatization [18–22, 32–42]. Analytical procedures for thiol determination usually involve reduction of disulfide bonds with tris(2-carboxyethyl)phosphine, tri-n-butylphosphine or mercaptoethanol, chemical derivatization of the sulfur compound with the use of 2-halopyridinium or 2-haloquinolinium salts and then deproteinization, followed by ion-pair reversed-phase HPLC or CE separation and spectrophotometric detection. Derivatization reaction takes advantage of great susceptibility of quinolinium or pyridinium molecules at 2-position to nucleophilic displacement, and a high nucleophilicity of the thiol group. Derivatization reaction mixture is usually ready to be analyzed just after mixing of the substrates. CMQT and BCPB exhibit very high reactivity toward thiols [44, 45], sulfides [63] as well as thiosulfates [40, 54]. 2-S-quinolinium and 2-S-pyridinium derivatives possess advantageous spectrophotometric and chromatographic properties. They are stable and more hydrophobic than thiols themselves, possessing a well-defined absorption maximum in the UV region. The reaction is accompanied by an analytically advantageous bathochromic shift from reagent maximum to the maximum of the derivative. Thanks to this phenomenon it is possible to use a large excess of derivatization reagent in order to drive the reaction to completion and avoid a huge signal of unreacted compound on the chromatogram [26]. Elaborated with the use of onium salts methods have proven to be useful in quantitative HPLC and CE analysis of endogenous and exogenous low-molecular-weight biological thiols in human body fluids, plant extracts and some groceries [44, 45].
    Źródło:
    Wiadomości Chemiczne; 2014, 68, 3-4; 211-232
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Enzymatyczne i chemiczne modyfikacje fosfolipidów
    Enzymatic and chemical modifications of phospholipids
    Autorzy:
    Chojnacka, Anna
    Niezgoda, Natalia
    Powiązania:
    https://bibliotekanauki.pl/articles/27310043.pdf
    Data publikacji:
    2023
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    fosfolipidy strukturyzowane
    koniugaty fosfolipidowe
    bioaktywne kwasy tłuszczowe
    modyfikacje fosfolipidów
    sprzężony kwas linolowy
    dehydroepiandrosteron
    niesteroidowe leki przeciwzapalne
    lipaza
    fosfolipaza
    structured phospholipids
    phospholipid conjugates
    bioactive fatty acids
    phospholipid modification
    dehydroepiandrosterone
    NSAIDs
    lipase
    phospholipase
    Opis:
    At the moment, phospholipids are among the most interesting molecules. The possibilities of chemical and enzymatic modifications, while maintaining their integrity and unique nature, also contribute to these compounds' great interest. This review paper concerns the preparation of new phospholipid conjugates containing fragments of biologically active compounds not found naturally in phospholipids, and phospholipids enriched with specific fatty acids with health-promoting properties (structured phospholipids). Chemical methods for the synthesis of phospholipids containing conjugated linolenic acid (CLA), dehydroepiandrosterone (DHEA) or selected non-steroidal anti-inflammatory drugs (NSAIDs) at the sn-1 and/or sn-2 position have been described. In addition, the evaluation of the antiproliferative activity of the obtained conjugates against selected cancer cell lines was also described. Enzymatic methods of modifying natural phospholipids leading to their enrichment with bioactive polyunsaturated fatty acids and conjugated acids have also been described.
    Źródło:
    Wiadomości Chemiczne; 2023, 77, 5-6; 449--477
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Nienaturalne aminokwasy jako strategia do otrzymywania substratów, inhibitorów i niskocząsteczkowych sond aktywności dla enzymów proteolitycznych
    Unnatural amino acids as achemical tool for the development of protease substrates, inhibitors and activity - baseproblems
    Autorzy:
    Poręba, Marcin
    Kasperkiewicz-Wasilewska, Paulina
    Rut, Wioletta
    Drąg, Marcin
    Powiązania:
    https://bibliotekanauki.pl/articles/2200587.pdf
    Data publikacji:
    2022
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    proteolytic enzymes
    substrate specificity
    unnatural amino acids
    substrates
    inhibitors
    activity-based probes
    caspases
    cathepsins
    neuthrophil serine proteases
    proteasome
    SARS-CoV-2 proteases
    enzymy proteolityczne
    specyficzność substratowa
    nienaturalne aminokwasy
    niskocząsteczkowe sondy aktywności
    kaspazy
    katepsyny
    proteasom
    proteazy wirusa SARS-CoV-2
    Opis:
    Proteolytic enzymes are molecular scissors that are responsible for the amide bond breakdown in peptide and protein substrates. Over the years, the view on proteases has been considerably changed from non-specific digestive enzymes to sophisticated biocatalysts, which by performing limited proteolysis control virtually all biological processes. In order to better understand how proteases work and what are their biologically relevant target substrates, it is indispensable to determine their catalytic preferences. This knowledge can be further utilized to develop selective substrates, inhibitors and activity-based probes (ABPs) enabling the monitoring of proteases activity in various settings, from in vitro analysis on recombinant enzymes or cell lysates to ex vivo and in vivo imaging at the single cell level. Among many chemical-based approaches that have been developed and applied over the years, the Hybrid Combinatorial Substrate Library (HyCoSuL) technology has emerged as one of the most powerful one. HyCoSuL is a combinatorial peptide-based library of fluorogenic substrates, that comprise natural and unnatural amino acids, that can deeply explore the chemical space in proteases active site, providing a structural framework for the development of highly-selective chemical tools. In this review we present the most prominent examples of proteolytic enzymes that have been profiled with HyCoSuL approach yielding selective substrates, potent inhibitors, and very sensitive activity-based probes.
    Źródło:
    Wiadomości Chemiczne; 2022, 76, 5-6; 433--454
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Modyfikowane oligodeoksyrybonukleotydy zawierające w wiązaniu internukleotydowym w pozycji mostkowej atom azotu
    Modified oligodeoxyribonucleotides containing nitrogen at a bridging position of an internucleotide bond
    Autorzy:
    Radzikowska, E.
    Powiązania:
    https://bibliotekanauki.pl/articles/172442.pdf
    Data publikacji:
    2013
    Wydawca:
    Polskie Towarzystwo Chemiczne
    Tematy:
    analogi kwasów nukleinowych
    modyfikacje wiązania internukleotydowego
    oligodeoksyrybonukleozydo-(P3’→N5’)amidofosforany
    oligodeoksyrybonukleozydo-(N3’→P5’)amido(tio)fosforany
    strategia antysensowa
    telomeraza
    reakcja Athertona-Todda
    nucleic acids analogues internucleotide linkage modifications
    oligodeoxyribonucleoside-(P3’→N5’)phosphoramidates
    oligodeoxyribonucleoside-
    (N3’→P5’)(thio)phosphoramidates antisense strategy
    telomerase
    Atherton-Todd reaction
    Opis:
    Synthetic oligonucleotides (ONs) constitute an important class of compounds which exhibit biological activity. As potential drugs ONs are employed in the antisense strategy [1]. The antisense therapeutic agent acts on the pathogenic mRNA causing inactivation of the target. Ideal antisense agent should be resistant to exo and/or endonucleases, have a suitable pharmacological and pharmacokinetic profile and high affinity for the target. To improve some properties of antisense oligonucleotides plethora of chemical modifications introduced within both sugar unit and internucleotides linkage were investigated. Among numerous ONs modified in internucleotide phosphodiester bond, one of the most interesting are oligonucleotide phosphoramidates (NP-oligos) in which one of the bridging oxygens is replaced by nitrogen atom (at 3’ or 5’ position). Hence, two classes of compounds are formed: oligonucleotide-(N5’→P3’)phosphoramidates and oligonucleotide(N3’→P5’)-phosphoramidates. These compounds, similar to native DNA and RNA, possess an achiral phosphorous atom and all internucleotides bonds are negatively charged. Additionally, NP-oligo shows good resistance to nucleolytic degradation and can bind to the target DNA or RNA with high affinity [12]. In literature several synthetic strategies concerning both (N5’→P3’) and (N3’→P5’) NP-oligos have been described. Some of them allowed to obtain only corresponding dimers. In the light of recent discoveries the most promising candidates for therapeutic and diagnostic applications are oligonucleotide-(N3’→P5’)thiophosphoramidates. Gryaznov et al. have found that such compounds can act as potent and selective telomerase inhibitors [29]. Human telomerase (TA) is a reverse transcriptase ribonucleoprotein that synthesizes de novo d-(TTAGGG)n repeats at chromosomal DNA ends. Whereas activity of this enzyme is observed in ~85% of all human tumors, most of normal somatic cells either lack TA activity or express it only at low levels. For these reasons TA constitute an attractive and nearly universal anticancer target for rational drug development.
    Źródło:
    Wiadomości Chemiczne; 2013, 67, 11-12; 1003-1025
    0043-5104
    2300-0295
    Pojawia się w:
    Wiadomości Chemiczne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
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