- Synthesis and structure-activity relationship of thiobarbituric acid derivatives as potent inhibitors of urease
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A series of thiobarbituric acid derivatives 1-27 were synthesized and evaluated for their urease inhibitory potential. Exciting results were obtained from the screening of these compounds 1-27. Compounds 5, 7, 8, 11, 16, 17, 22, 23 and 24 showed excellent urease inhibition with IC50 values 18.1 ± 0.52, 16.0 ± 0.45, 16.0 ± 0.22, 14.3 ± 0.27, 6.7 ± 0.27, 10.6 ± 0.17, 19.2 ± 0.29, 18.2 ± 0.76 and 1.61 ± 0.18 μM, respectively, much better than the standard urease inhibitor thiourea (IC50 = 21 ± 0.11 μM). Compound 3, 4, 10, and 26 exhibited comparable activities to the standard with IC50 values 21.4 ± 1.04 and 21.5 ± 0.61μM, 22.8 ± 0.32, 25.2 ± 0.63, respectively. However the remaining compounds also showed prominent inhibitory potential The structure-activity relationship was established for these compounds. This study identified a novel class of urease inhibitors. The structures of all compounds were confirmed through spectroscopic techniques such as EI-MS and 1H NMR.
- Khan, Khalid Mohammed,Rahim, Fazal,Khan, Ajmal,Shabeer, Muhammad,Hussain, Shafqat,Rehman, Wajid,Taha, Muhammad,Khan, Momin,Perveen, Shahnaz,Choudhary, M. Iqbal
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p. 4119 - 4123
(2014/08/18)
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- A green approach to the synthesis of fused uracils: Pyrano[2,3-d] pyrimidines. On-water one-pot synthesis by domino Knoevenagel/Diels-Alder reactions
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On-water Knoevenagel condensations of 2-thiobarbituric acid and N,N-dimethylbarbituric acid with aromatic and heteroaromatic aldehydes were carried out without a catalyst and at room temperature. Condensations in aqueous suspensions occurred rapidly, giving excellent yields. Solvent-free hetero-Diels-Alder reactions of 5-arylidene derivatives of barbituric acids with ethyl vinyl ether were investigated at room temperature and pyrano[2,3-d]pyrimidines of potential pharmacological activity were obtained in excellent yields. Three-component one-pot syntheses of annulated uracils were performed in aqueous suspensions. Reactions of barbituric acids, aldehydes, and ethyl vinyl ether were carried out at ambient temperature, whereas the one-pot synthesis with barbituric acids, aldehydes, and styrene or N-vinyl-2- oxazolidinone required the heating of aqueous suspensions at 60°C. On-water cycloadditions were characterized by high diastereoselectivity in contrast to reactions carried out in homogeneous organic media (dichloromethane, toluene). They allowed the cis adducts to be obtained preferentially or exclusively. The presented green methods avoid the use of catalysts, the heating of reaction mixtures for long times at high temperatures, and the use of organic solvents, and make the synthesis of a variety of pyrano[2,3-d]pyrimidines chemically efficient. The results reveal water as the medium of choice for the examined cycloadditions. Georg Thieme Verlag Stuttgart - New York.
- Paasz, Aleksandra
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experimental part
p. 4021 - 4032
(2011/02/21)
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