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Wyświetlanie 1-5 z 5
Tytuł:
Aktywność biologiczna pochodnych tiazolo[4,5-d]pirymidyny
Biological activity of thiazolo[4,5-d]pyrimidine derivatives
Autorzy:
Becan, L.
Powiązania:
https://bibliotekanauki.pl/articles/171536.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
pochodne tiazolo[4,5-d]pirymidyny synteza
aktywność biologiczna
thiazolo[4,5-d]pyrimidine derivatives synthesis
biological activity
Opis:
Thiazolo[4,5-d]pyrimidine is one of the six structural isomers of the bicyclic ring system containing thiazole moiety fused with the pyrimidine. There are six structural isomers depending on the position of the nitrogen atoms. The isomer [4,5-d] does not contain the bridge-head nitrogen and can be considered as 7-thio analogue of the natural purine bases such as guanine and adenine. Due to the great of their biological potential the newly synthesized compounds are evaluated for various pharmacological activities. This review presents numerous thiazolo[4,5-d]pyrimidine derivatives reported for their interesting biological activity including antibacterial [2, 3, 5, 7, 8, 10, 19], antifungal [2–6, 9, 10], antiviral [11–13], analgesic [18, 19], antidepressant [17] and anticancer properties [23–26]. Some urea and thiourea derivatives exhibited significant antiparkinsonian activity [14–16]. Tumor necrosis factor (TNF) promotes an inflammatory response, which in turn causes many of the clinical problems associated with autoimmune disorders. Ethyl 4-(2-amino-5,7-dioxo-3,4,5,7-tetrahydro-thiazolo[4,5-d]pyrimidin- 6(2H)-yl)butanoate derivatives 29 (Fig. 24) as a TNFα inhibitors have a potential use in the treatment of diseases such as refractory asthma, psoriasis, rheumatoid arthritis, irritable bowel syndrome, and other [21]. Blocade of the CXCR2 receptor by thiazolo[4,5-d]pyrimidine-2(3H)-ones also represents an attractive strategy for treatment of inflammatory diseases [20]. Recently there have been developed CX3CR1 receptor antagonists for the treatment of multiple sclerosis [22]. Isatoribine, 5-amino-3-β-D-ribofuranosyl-3H-thiazolo[4,5-d]pyrimidin-2-one (20) (Fig. 15) is a small molecule toll-like receptor 7 (TLR7) agonist and an activator of innate immunity. Its orally bioavailable analogue ANA 975 (Fig. 16) has been reported for probable use in treating disease states associated with abnormal cell growth, such as cancer and has anti HCV activity [13]. Thiazolo[4,5-d]pyrimidines inhibit the growth of the weeds which implies that they have a potential as herbicides [27].
Źródło:
Wiadomości Chemiczne; 2013, 67, 11-12; 1051-1074
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Syntezy układu tiazolo[4,5-d]pirymidyny
Syntheses of the thiazolo[4,5-d]pyrimidine system
Autorzy:
Becan, L.
Powiązania:
https://bibliotekanauki.pl/articles/172601.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
pochodne tiazolo[4,5-d]pirymidyny
metoda otrzymywania
synteza
synteza bicyklicznego układu
thiazolo[4,5-d]pyrimidine derivatives
synthesis
ring system
method of obtaining
Opis:
This review is focused on the literature data about the preparation of the thiazolo[4,5-d]pyrimidine scaffold. The synthesis of this ring system has been accomplished by various methods. The synthesis can proceed via a pyrimidine onto which a thiazole ring can be annulated. The second approach involve annulation of a pyrimidine ring onto the preformed thiazole ring. Thiazolo[4,5-d]pyrimidines have been obtained by condensation of pyrimidine derivatives with thioamides [2], thionyl chloride [3], thiourea [4], bromomalononitrile [5], isothiocyanates [6] or under the influence of temperature [7]. However, most of the literature refers the methods of synthesis which begin with formation of the appropriately substituted thiazole ring. This synthetic route for preparation of fused derivatives utilizes orhtoesters [8, 9], acetic anhydride [9,10], formic acid derivatives [11, 12], carbon disulfide [13,14], appropriate isothiocyanates [15-18], urea and hydrazine derivatives [19–23], aromatic aldehydes and acid chlorides [24, 25] as key building blocks. Cyclization also occurs in high temperature or acidic reaction medium [26, 27]. The solid-phase synthesis was also described [28].
Źródło:
Wiadomości Chemiczne; 2014, 68, 1-2; 95-116
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
D-Rybono-1,4-lakton. Część 1, Otrzymywanie i wybrane pochodne
D-Ribono-1,4-lactone. Part 1, Preparation and seleced derivatives
Autorzy:
Madaj, J.
Samaszko-Fiertek, J.
Ślusarz, R.
Dmochowska, B.
Powiązania:
https://bibliotekanauki.pl/articles/171744.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
D-Rybono-1,4-lakton
otrzymywanie
wybrane pochodne
D-Ribono-1,4-lactone
preparation
seleced derivatives
Opis:
Sugars are extremely important chiral substrates in organic synthesis. Thanks to the possibility of obtaining them from natural sources, their prices are relatively low which increases their attractiveness. d-Ribono-1,4-lactone is included in these compounds. For years it has enjoyed great interest as a substrate. In the early 1980’s two review articles were published in reputable journals [4, 5]. It has been a long time since these articles were published so we have decided to prepare a more up- -to-date review article in Polish. d-Ribono-1,4-lactone can be synthesized in many ways. The most interesting way seems to be the oxidation with KMnO4 [9] or molecular Br2 [10]. The use of bromine may appear to be harmful to the environment. That is why the search for more environmentally friendly methods is ongoing. However, the new methods are not as sufficiently satisfactory and often more expensive than the conventional, previously named methods. Therefore, the most commonly used method is the oxidation of D-ribose with molecular bromine. Very important derivatives of d-ribonolactone are acetal derivatives: 2,3-O-isopropylidene [10, 16] and 3,4-O-benzylidene derivatives [17]. They are often the starting materials for further synthesis. In the case of the latter compound the proper structure was determined by crystallography many years after its synthesis [18]. Very important group of derivatives are derivatives modificated at C-5: sulphonic [21], fluorine [22], chlorine [23], bromine [16, 24], azide [25] and phosphate [27]. Especially important are 5-bromo-5-deoxy derivatives. Examples of their use for the synthesis of thioalditols and thiosugars are described in the literature. It is also worth mentioning the possibility of synthesis of 1,2-unsaturated [28–30] and 2,3-unsaturated [31] derivatives. Presented examples of derivatives prove that using a d-ribono-1,4-lactone a whole range of derivatives extremely useful for further synthesis of more complex compounds can be obtained.
Źródło:
Wiadomości Chemiczne; 2017, 71, 11-12; 844-859
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fotokatalityczna degradacja herbicydów : nowe katalizatory na bazie TiO2
Photocatalytic degradation of herbicydes : new catalysts based on TiO2
Autorzy:
Ożóg, S.
Powiązania:
https://bibliotekanauki.pl/articles/172094.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
tlenek tytanu
TiO2
degradacja fotokatalityczna
kwas 2,4-dichlorofenoksyoctowy
2,4-D
kwas 2,4,5-trichlorofenoksyoctowy
2,4,5-T
4G-PHOTOCAT
titanium dioxide
photocatalytic degradation
2,4-dichlorophenoxyacetic
2,4,5-trichlorophenoxyacetic
Opis:
Over the past few decades a rapid increase in standard of living is observed. Rapid urbanization and development of new technologies, which are focused on the needs of a modern society, influence negatively the environment. The present policy of sustainable development is focused on the principles of rational use of scarce resources and raw materials. New technologies should comply with a number of requirements: efficiency, low costs and a low impact on the environment. Photocatalytic processes are the answer for these requirements. Photocatalysis can be used in many aspects of everyday life, offering self-cleaning surfaces, photo-drugs (e.g. for photodynamic therapy) and even photovoltaic devices. Photocatalytic degradation of pollutants in the presence of inorganic photocatalysts (e.g. TiO2 or ZnO) is one of the available methods of removing impurities from aqueous and gaseous phases. The main advantage of this process is the lack of wastes and formation of carbon dioxide, water and simple inorganic ions as end- -products. The aim of our work was to develop new TiO2-based photocatalysts doped with tungsten and molybdenum oxides. A series of materials with different content of the dopants, calcined at various temperatures, was prepared. The photocatalytic activity of the materials was determined following the degradation of two model herbicides: 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T). These compounds are used for the control of weed growth on crop plantations, but in a high dosage they can lead to destruction of the plants. They are readily soluble in water, therefore their use is simple, but brings a great risk to aquatic organisms and people. Photocatalytic degradation of herbicides is the main goal of the 4G-PHOTOCAT project. The efforts are directed towards development of a low-cost photocatalytic paint, that could be used in reactors for groundwater purification. The active ingredient of the paint is a composite material based on TiO2 modified with other metal oxides.
Źródło:
Wiadomości Chemiczne; 2015, 69, 7-8; 606-616
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
D-Rybono-1,4-lakton. Część 2, Wykorzystanie w syntezie organicznej – wybrane reakcje
D-Ribono-1,4-lactone. Part 2, Use in organic synthesis – selected reactions
Autorzy:
Madaj, J.
Samaszko-Fiertek, J.
Ślusarz, R.
Dmochowska, B.
Powiązania:
https://bibliotekanauki.pl/articles/171521.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
D-Rybono-1,4-lakton
C-glikozydy
analogi nukleozydów
neplanocyna
D-ribono-1,4-lactone
C-glycosides
nucleosides analogs
neplanocin
Opis:
There are many examples of syntheses with d-ribono-1,4-lactone as a substrate. Among all, its biggest advantage is undoubtedly its accessibility. It can be synthesized on a large scale from naturally available raw materials. Its characteristic feature is the stable configuration of individual carbon atoms in multiple reaction conditions. Very important is the presence of a carbonyl moiety, allowing for a variety of additions which is crucial for carbon-carbon bond formation, the most difficult synthesis in organic chemistry. In this article we present selected examples of articles that were published after 1984. In this year, the second article describing the Use of d-Ribonolactone in Organic Synthesis [36] was published. After this time many articles describing the use of the entitled lactone as a substrate in organic synthesis were published. We thought it would be worthwhile to present in Polish a selection of them. C-Glycosides and nucleoside analogs are a particularly important type of synthesized products. Examples of their synthesis are presented in this work, namely, neplanocin A [5], B [31] and F [24], citreovirdin [14], 2-bromopyridin α- and β-d-ribofuranosides [10], 4-deazaformicin A [27] and varitriol [ 33].
Źródło:
Wiadomości Chemiczne; 2017, 71, 11-12; 861-885
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-5 z 5

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