44 research outputs found

    Synthesis, biological activity and molecular modelling studies of tricyclic alkylimidazo-, pyrimido- and diazepinopurinediones

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    Syntheses and biological activities of imidazo-, pyrimido- and diazepino[2,1-f]purinediones containing N-alkyl substituents (with straight, branched or unsaturated chains) are described. Tricyclic derivatives were synthesized by the cyclization of 8-bromo-substituted 7-(2-bromoethyl)-, 7-(3-chloropropyl)- or 7-(4-bromobutyl)-theophylline with primary amines under various conditions. Compound 22 with an ethenyl substituent was synthesized by dehydrohalogenation of 9-(2-bromoethyl)-1,3-dimethyltetrahydropyrimido[2,1-f]purinedione. The obtained derivatives (5-35) were initially evaluated for their affinity at rat A1 and A2A adenosine receptors (AR), showing moderate affinity for both adenosine receptor subtypes. The best ligands were diazepinopurinedione 28 (K i = 0.28 μM) with fivefold A2A selectivity and the non-selective A1/A2A AR ligand pyrimidopurinedione 35 (K i A1 = 0.28 μM and K i A2A = 0.30 μM). The compounds were also evaluated for their affinity at human A1, A2A, A2B and A3 ARs. All of the obtained compounds were docked to the A2A AR X-ray structure in complex with the xanthine-based, potent adenosine receptor antagonist-XAC. The likely interactions of imidazo-, pyrimido- and diazepino[2,1-f]purinediones with the residues forming the A2A binding pocket were discussed. Furthermore, the new compounds were tested in vivo as anticonvulsants in maximal electroshock, subcutaneous pentylenetetrazole (ScMet) and TOX tests in mice (i.p.). Pyrimidopurinediones showed anticonvulsant activity mainly in the ScMet test. The best derivative was compound 11, showing 100 % protection at a dose of 100 mg/kg without symptoms of neurotoxicity. Compounds 6, 7, 8 and 14 with short substituents showed neurotoxicity and caused death. In rat tests (p.o.), 9 was characterized by a high protection index (>13.3). AR affinity did not apparently correlate with the antiepileptic potency of the compounds

    Estimating Mechanical Properties of Wood in Existing Structures—Selected Aspects

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    The paper presents and discusses selected methods of wood classification and the evaluation of its mechanical properties. Attention was mainly paid to methods that may be particularly useful for examining existing elements and structures. The possibility of estimating the modulus of rupture—MOR and modulus of elasticity—MOE based on the non- destructive (NDT), semi-destructive (SDT), and destructive tests (DT) were considered. Known international, European, and American standards and research approaches were indicated. The selected testing methods and their interpretation were presented. These were, among others, the method of visual assessment, the resistance drilling method, methods of determining the dynamic modulus of elasticity, and procedures for testing small clear specimens. Moreover, some of our own research results from the conducted experimental tests were presented and discussed. In the destructive tests, both large elements and small clear specimens were examined. The results obtained from individual methods were compared and some conclusions were presented. The summary discusses the fundamental difficulties and limitations in applying the presented procedures and interpretations

    Investigating glazed ceramics in relation to renovation of the façade of a 19ᵗʰ century heritage building

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    W artykule przedstawiono zagadnienia dotyczące szkliwionych kształtek ceramicznych na elewacji historycznego budynku w kontekście prowadzonych prac remontowych. Zaprezentowano charakterystykę ceramiki szkliwionej stosowanej w obiektach historycznych: jej właściwości fizykochemiczne, krótki rys historyczny stosowania tego typu ceramiki na ziemiach polskich oraz przykłady obiektów z cegłami szkliwionymi z różnych okresów historycznych i stron świata. Następnie opisano prace związane z remontem elewacji ceramicznej na przykładzie XIX-wiecznego budynku we Wrocławiu, w tym różne metody czyszczenia elewacji oraz badania mrozoodporności. Przedstawiono wyniki przeprowadzonych prób i badań oraz wnioski co do tego, które metody czyszczenia i renowacji przynoszą zadowalające efekty. Opisano także zastosowane na elewacji obiektu rozwiązania naprawcze.The paper discusses issues concerning glazed ceramic patterns on the façade of an historical building in relation to ongoing renovation work. The characteristics of glazed ceramic materials used in historical buildings are presented: its physical and chemical parameters, a brief history of the use of ceramic materials in Poland and examples of buildings with glazed bricks dating from different historical time period and different parts of the world. This is followed by a description of renovation work of a ceramic façade based on an example of a 19ᵗʰ century building in Wroclaw. Different methods of cleaning the façade and testing freeze-thaw resistance are discussed. The results of the sampling and testing are presented, along with conclusions as to which cleaning and renovation methods bring satisfactory results. Solutions used to repair the building façade are also described

    Investigation of wooden sheet pile wall in an aggressive environment using non-destructive methods

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    The paper presents the study of the strength parameters of wood samples from the retaining structure, working for about 60 years in an aggressive sea water environment. Samples from the variable water level zone and situated in the watered ground were tested. Non-destructive examinations were performed using the following methods: the stress wave technique and the ultrasonic wave technique. The results presented below can lead to the conclusion that both methods: the stress wave by Fakopp Microsecond Timer device and the ultrasonic wave by Sylvatest Trio correspond with each other and result in similar outcomes. However, in order to obtain more detailed and comprehensive information on the elements properties, more research should be conducted

    Determination of the Phenolic Profile and Antioxidant Properties of Salvia viridis L. Shoots: A Comparison of Aqueous and Hydroethanolic Extracts

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    Salvia viridis L. is an annual herb used in Mediterranean medicine. The purpose of this study was to determine the polyphenol profile of aqueous (decoction and infusion) and hydroethanolic extracts of aerial parts of field-grown S.viridis and to evaluate their antioxidant activity. The polyphenol profiling was performed via UPLC-DAD/ESI-MS. Additionally, the total polyphenol content in extracts tested were determined by UV-Vis spectrophotometry using the Folin-Ciocalteu assay. The antioxidant effect was evaluated by the FRAP, DPPH, ABTS, O2•− scavenging and TBARS methods. The hydroethanolic extract gave the highest content of total phenolic compounds, followed by the infusion. The UPLC-DAD/ESI-MS analysis of extracts showed a total of 19 phenolic compounds identified as flavonoids (four compounds), phenylethanoids (eight compounds) and phenolic acids (seven compounds). Rosmarinic acid was the predominant phenolic acid, verbascoside was the predominant phenylethanoid, while apigenin glucuronide or methylluteolin glucuronide, depending on the sample, were the predominant flavonoids in the analyzed extracts. The presence of a high polyphenol level indicated a high antioxidant activity of both the infusion and the hydroalcoholic extract. These results indicate that S. viridis is a rich resource of phenolic compounds and can be used in dietary applications with the potential to reduce oxidative stress

    Investigation of wooden sheet pile wall in an aggressive environment using non-destructive methods

    No full text
    The paper presents the study of the strength parameters of wood samples from the retaining structure, working for about 60 years in an aggressive sea water environment. Samples from the variable water level zone and situated in the watered ground were tested. Non-destructive examinations were performed using the following methods: the stress wave technique and the ultrasonic wave technique. The results presented below can lead to the conclusion that both methods: the stress wave by Fakopp Microsecond Timer device and the ultrasonic wave by Sylvatest Trio correspond with each other and result in similar outcomes. However, in order to obtain more detailed and comprehensive information on the elements properties, more research should be conducted

    Assessment of the Condition of Wharf Timber Sheet Wall Material by Means of Selected Non-Destructive Methods

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    This paper presents an assessment of the condition of wood coming from a wharf timber sheet wall after 70 years of service in a (sea) water environment. Samples taken from the structure’s different zones, i.e., the zone impacted by waves and characterised by variable water-air conditions, the zone immersed in water and the zone embedded in the ground, were subjected to non-destructive or semi-destructive tests. Also, the basic parameters of the material, such as its density and moisture content, were determined. Moreover, the ultrasonic, stress wave and drilling resistance methods were used. Then, an X-ray microtomographic analysis was carried out. The results provided information about the structure of the material on the micro and macroscale, and the condition of the material was assessed on their basis. Also, correlations between the particular parameters were determined. Moreover, the methods themselves were evaluated with regard to their usefulness for the in situ testing of timber and to estimate, on this basis, the mechanical parameters needed for the static load analysis of the whole structure
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