1,720,983 research outputs found
“Novel and Highly Selective Postsynaptic α-Adrenoreceptor Antagonists: Synthesis and Structure-Activity Relationships of Alkane-Bridged [4-(phenoxyethyl)-1-piperazinyl]-3 (2H)-pyridazinones”.
No full textNew 4-(4-methyl-phenyl)phthalazin-1(2H)-one derivatives and their effects on alpha(1)-receptors
No full textContinuing our research aimed at obtaining new Compounds with high affinity and selectivity toward alpha(1)-AR, a new series of arylpiperazine derivatives was designed, synthesized, and biologically tested. The new Compounds 1-17 are characterized by a phenylphthalazin-1(2H)-one fragment connected through an alkyl chain to an arylpiperazine residue. The pharmacological profile of these compounds was evaluated for their affinity and selectivity toward alpha(1)-AR, alpha(2)-AR and toward 5HT(1A) serotoninergic receptor. A discussion on the structure-activity relationship (SAR) of these compounds is also reported
Structure-Activity Relationships in a Series of 8-Substituted Xantines as A1-Adenosine Receptor Antagonists
No full textStructure-activity relationships in a series of 8-substituted xanthines as bronchodilator and A(1)-adenosine receptor antagonists
No full textFour new derivatives of 8-piperazine ethyl xanthine were synthesized and their bronchospasmolytic activity and A(1)-adenosine affinity were studied. Their relaxant action in the tracheal muscle was lower than that of theophylline and that of theophylline derivatives substituted at the 7-position. Only compound 9, where the methyl group in the 1-position of the theophylline was substituted by an isobutyl group, shows a good affinity towards the A(1)-adenosine receptor
2-{[(2-(2,6-Dimethoxyphenoxy)ethyl]}-1,4-benzoxathiano:A New Antagonist With High Potency and Selectivity Toward alpha1-Adrenoreceptors.
No full textThese results emphasize the importance of the position 4 in both thebenzodioxan and benzoxathian nucleus for the interactionat a,-adrenoreceptors. Since sulfur cannot form a productivehydrogen bond, the position 4 of antagonists bearinga benzodioxan or a benzoxathian nucleus would interactwith the receptor, either increasing the electron densityof the phenyl ring by a way of an electron-releasing effector giving rise to a dipole-dipole interaction.In conclusion, compound 1 is a potent and selectivealpha1-adrenoreceptor antagonist that may represent a valuabletool in the characterization of a-adrenoreceptor subtypes
Structure-activity relationships in a series of 8-substituted xanthines as A(1)-adenosine receptor antagonists
No full textA series of X-substituted xanthines were synthesized and their affinity in vitro towards A(1), A(2A)-adenosine receptors was evaluated by radioligand receptor binding assays. All compounds showed a greater affinity and selectivity towards the A(1)-adenosine receptor than theophylline. The compounds in which the n-proyl group is in 1-position of the xanthine nucleus and the pyridazinone system in 8-position is linked through a chain of two or four carbon atoms, showed the highest affinity and selectivity. (C) 2001 Elsevier Science Ltd. All rights reserved
“New Pyridazinones: Synthesis and Correlation Between Structure and α-Blocking Activity”.
No full textArylpiperazines with high affinity toward a1-adrenergic receptors
No full textIn the last years, α1 adrenoceptors (α1-AR) have been the subject of intense research, in part because receptor-binding studies and molecular biology have opened up new aspects of understanding but also because of the potential to find new drugs possibly acting toward pathophysiological processes where α1-AR are involved, such as benign prostatic hyperplasia (BPH) or hypertension. At present, arylpiperazines represent one of the most studied classes of molecules with affinity at α1-AR. In fact, a large amount of work has been done and reported, describing synthetic procedures, biological evaluation at both α1-AR and the corresponding subtypes, and structure-activity relationships (SARs). In this paper, a review based on a literature survey aimed at focusing on the structural properties that a compound should possess to show affinity toward α1-AR is presented. Moreover, the identification and optimization of the structural features of a hit compound derived from a pharmacophore-based database search, leading to a new class of arylpiperazinylalkyl pyridazinone derivatives with α1-AR affinity is reported
Design, Synthesis, and a1-Adrenoceptor Binding Properties of New Arylpiperazine Derivatives bearing a Flavone Nucleus as the Terminal Heterocyclic Molecular Portion
No full textFollowing our research project aimed at obtaining new compounds with high affinity and selectivity toward α1-adrenoceptors (AR), a new class of piperazine derivatives was designed, synthesized and biologically tested. The new compounds 1-13 are characterized by a flavone system linked, through an ethoxy or propoxy spacer, to a phenyl- or pyridazinone-piperazine moiety. Biological data showed an interesting profile for the phenylpiperazine subclass found to have a nanomolar affinity toward α1-AR, and less pronounced affinity for α2-AR and the 5-HT1A serotoninergic receptor. A discussion on the structure-activity relationship (SAR) of such compounds is also reported, on the basis of the flavone substitution pattern, length and functionalization of the spacer, and disruption of the phenylpiperazine system
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