- Synthesis and Pharmacological Evaluation of Novel Arginine Analogs as Potential Inhibitors of Acetylcholine-Induced Relaxation in Rat Thoracic Aortic Rings
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It is widely appreciated that the vascular endothelium is capable of modulating vascular smooth muscle tone suiting it well for its role as an important regulator of a number of diverse biological processes. Endothelial dysfunction is an early manifestation of atherothrombosis and a consequence of the established disease. Although several arginine derivatives alkylated at one of the guanidino nitrogen were found to inhibit vasorelaxation induced by acetylcholine, activity of the corresponding arginine esters is not reported. The present work was therefore designed to synthesize and evaluate series of novel arginine derivatives to obtain further insight into structure-activity relationship in this series of compounds. Present study involves assessment of activity of these novel compounds on the vascular tone of rat thoracic aorta in comparison with l-arginine analog, that is, l-nitro-arginine methyl ester (l-NAME). Results from the present study showed that full reversal of phenylephrine-mediated contraction was achieved by cumulative applications of acetylcholine (3nm-300μm), which were abolished when the aortic rings were pretreated with l-NAME (300μm). Results from the present study demonstrated that these novel arginine derivatives cause significant yet reversible reduction in acetylcholine-mediated relaxation, similar to that of l-NAME.
- Jain, Manish,Barthwal, Manoj Kumar,Haq, Wahajul,Katti, Seturam B.,Dikshit, Madhu
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experimental part
p. 459 - 469
(2012/06/18)
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- Inhibitors of N α-acetyl-l-ornithine deacetylase: Synthesis, characterization and analysis of their inhibitory potency
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A series of N α-acyl (alkyl)- and N α- alkoxycarbonyl-derivatives of l- and d-ornithine were prepared, characterized, and analyzed for their potency toward the bacterial enzyme N α-acetyl-l-ornithine deacetylase (ArgE). Ar
- Hlavacek,Picha,Vanek,Jiracek,Slaninova,Fucik,Budesinsky,Gilner,Holz
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experimental part
p. 1155 - 1164
(2010/08/06)
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- Inhibitors or bone reabsorption and antagonists of vitronectin receptors
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Novel inhibitors of bone reabsorption and antagonists of vitronectin receptors The present invention relates to 5-membered ring heterocycles of the formula I, in which E, F, G, W, Y and Z have the meaning given in the patent claims, to their preparation a
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- Synthesis and in Vitro Biological Activity of New Deaza Analogues of Folic Acid, Aminopterin, and Methotrexate with an L-Ornithine Side Chain
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The 5-deaza and 5,8-dideaza analogues of Nα-pteroyl-L-ornithine (Pter-Orn), the 5-deaza, 8-deaza, and 5,8-dideaza analogues of Nα-(4-amino-4-deoxypteroyl)-L-ornithine (APA-Orn), and the Nδ-carboxymethyl derivative of Nα-(4-amino-4-deoxy-N10-methylpteroyl)-L-ornithine (m-APA-Orn) were synthesized and tested as inhibitors of dihydrofolate reductase (DHFR) and as inhibitors of tumor cell growth in culture.Reductive amination of 2-acetamido-6-formylpyridopyrimidin-4(3H)-one with methyl Nα-(4-aminobenzoyl)-Nδ-(benzyloxycarbonyl)-L-ornithinatefollowed by removal of the blocking groups afforded the 5-deaza analogue of Pter-Orn, whereas N-alkylation of methyl Nα-(4-aminobenzoyl)-Nδ-(benzyloxycarbonyl)-L-ornithinate with 2-amino-6-(bromomethyl)quinazolin-4(3H)-one and deprotection gave the corresponding 5,8-dideaza analogue.Reductive coupling of 2,4-diaminopyridopyrimidine-6-carbonitrile and 4-aminobenzoic acid followed by reaction with 96-97percent formic acid yielded 4-amino-4-deoxy-5-deaza-N10-formylpteroic acid, which on condensation with methyl Nδ-(benzyloxycarbonyl)-L-ornithinate and deprotection gave the 5-deaza analogue of APA-Orn.A similar sequence starting from 2,4-diaminoquinazoline-6-carbonitrile led to the corresponding 5,8-dideaza compound, whereas treatment of 2,4-diaminopyridopyrimidine-6-methanol with phosphorus tribromide followed by condensation with methyl Nα-(4-aminobenzoyl)-Nδ-(benzyloxycarbonyl)-L-ornithinate and deprotection afforded the 8-deaza analogue.For the preparation of the Nδ-carboxymethyl derivative of mAPA-Orn, Nα-(benzyloxycarbonyl)-L-ornithine was subjected to Nδ-monoalkylation with glyoxylic acid and sodium cyanoborohydride, followed by Nδ-acylation with ethyl trifluoroacetate, Nα-deprotection by hydrogenolysis, condensation with 4-amino-4-deoxy-N10-methylpteroic acid, and Nδ-deprotection by gentle treatment with ammonia.The 2,4-diamino derivatives all inhibited the growth of tumor cells in culture, with IC50 values of 0.2-2 μM, and inhibited purified DHFR with IC50 values of 0.02-0.08 μM.Deletion of ring nitrogens and Nδ-carboxymethylation both increased potency in the cell growth assay; however, the ornithine derivatives were less potent than aminopterin or methotrexate.
- Rosowsky, Andre,Forsch, Ronald A.,Bader, Henry,Freisheim, James H.
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p. 1447 - 1454
(2007/10/02)
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