Structure−Activity Relationship of Quinoline Derivatives as Potent and Selective α2C-Adrenoceptor Antagonists
摘要:
Starting from two acridine compounds identified in a high-throughput screening campaign (1 and 2, Table 1), a series of 4-aminoquinolines was synthesized and tested for their properties on the human alpha(2)-adrenoceptor subtypes (alpha(2A), alpha(2B), and alpha(2C.)). A number of compounds with good antagonist potencies against the alpha(2C)-adrenoceptor and excellent subtype selectivities over the other two subtypes were discovered. For example, (R)-{4-[4-(3,4-dimethylpiperazin-1-yl) phenylamino] quinolin- 3- yl} methanol 6j had an antagonist potency of 8.5 nM against, and a subtype selectivity of more than 200-fold for, the alpha(2C)-adrenoceptor. Investigation of the structure-activity relationship identified a number of structural features, the most critical of which was an absolute need for a substituent in the 3-position of the quinoline ring. The 3-position on the piperazine ring was also found to play an appreciable role, as substitutions in that position exerted a significant and stereospecific beneficial effect on the alpha(2C)-adrenoceptor affinity and potency. Replacing the piperazine ring proved difficult, with 1,4-diazepanes representing the only viable alternative.
Structure−Activity Relationship of Quinoline Derivatives as Potent and Selective α2C-Adrenoceptor Antagonists
摘要:
Starting from two acridine compounds identified in a high-throughput screening campaign (1 and 2, Table 1), a series of 4-aminoquinolines was synthesized and tested for their properties on the human alpha(2)-adrenoceptor subtypes (alpha(2A), alpha(2B), and alpha(2C.)). A number of compounds with good antagonist potencies against the alpha(2C)-adrenoceptor and excellent subtype selectivities over the other two subtypes were discovered. For example, (R)-{4-[4-(3,4-dimethylpiperazin-1-yl) phenylamino] quinolin- 3- yl} methanol 6j had an antagonist potency of 8.5 nM against, and a subtype selectivity of more than 200-fold for, the alpha(2C)-adrenoceptor. Investigation of the structure-activity relationship identified a number of structural features, the most critical of which was an absolute need for a substituent in the 3-position of the quinoline ring. The 3-position on the piperazine ring was also found to play an appreciable role, as substitutions in that position exerted a significant and stereospecific beneficial effect on the alpha(2C)-adrenoceptor affinity and potency. Replacing the piperazine ring proved difficult, with 1,4-diazepanes representing the only viable alternative.
A compound of formula I,
1
wherein A, Ra, Rb, R
1
to R
5
, m and t are as defined as disclosed, or a pharmaceutically acceptable salt or ester thereof, useful as an alpha-2 antagonist. The compounds I can be used for the treatment of diseases or conditions where alpha-2 antagonists are indicated to be effective.
A compound of formula I,
wherein A, Ra, Rb, R1 to R5, m and t are as defined as disclosed, or a pharmaceutically acceptable salt or ester thereof, useful as an alpha-2 antagonist. The compounds I can be used for the treatment of diseases or conditions where alpha-2 antagonists are indicated to be effective.
Oxidative stress is widely recognized as being associated with a number of disorders, including metabolic dysfunction and atherosclerosis. A series of substituted 4-quinolone derivatives were prepared and evaluated as inhibitors of reactive oxygen species (ROS) production from human umbilical vein endothelial cells (HUVECs). One compound in particular, 2-([4-(3-hydroxy-3-methylbutoxy)pyridin-2-yl]oxy}-methyl)- 3-methylquinolin-4(1H)-one (25b), inhibited ROS production from HUVECs with an IC50 of 140 nM. This compound also exhibited low CYP2D6 inhibitory activity, high aqueous solubility, and good in vitro metabolic stability. An in vivo pharmacokinetic study of this compound in SD rats revealed high oral bioavailability and a long plasma half-life. (C) 2011 Elsevier Ltd. All rights reserved.