New 2-arylpyrazolo[4,3-c]quinoline derivatives as potent and selective human A3 adenosine receptor antagonists.
In this paper we report the synthesis and biological evaluation of a new class of 2-phenyl-2,5-dihydro-pyrazolo[4,3-c]quinolin-4-ones as A(3) adenosine receptor antagonists. We designed a new route based on the Kira-Vilsmeier reaction for the synthesis of this class of compounds. Some of the synthesized compounds showed A(3) adenosine receptor affinity in the nanomolar range and good selectivity as evaluated in radioligand binding assays at human (h) A(1), A(2A), A(2B), and A(3) adenosine receptor subtypes. We introduced several substituents on the 2-phenyl ring. In particular substitution at the 4-position by methyl, methoxy, and chlorine gave optimal activity and selectivity 6c (K(i)hA(1), A(2A)>1000 nM, EC(50)hA(2B)>1000 nM, K(i)hA(3) = 9 nM), 6d (K(i)hA(1), A(2A)>1000 nM, EC(50)hA(2B)>1000 nM, K(i)hA(3) = 16 nM), 6b (K(i)hA(1), A(2A) >1000 nM, EC(50)hA(2B)>1000 nM, K(i)hA(3) = 19 nM). In conclusion, the 2-phenyl-2,5-dihydro-pyrazolo[4,3-c]quinolin-4-one derivatives described herein represent a new family of in vitro selective antagonists for the adenosine A(3) receptor.
Baraldi
Pier Giovanni
PG
Dipartimento di Scienze Farmaceutiche, Dipartimento di Medicina Clinica e Sperimentale-Sezione di Farmacologia, Università di Ferrara, 44100 Ferrara, Italy. pgb@dns.unife.it
Tabrizi
Mojgan Aghazadeh
MA
Preti
Delia
D
Bovero
Andrea
A
Fruttarolo
Francesca
F
Romagnoli
Romeo
R
Zaid
Naser Abdel
NA
Moorman
Allan R
AR
Varani
Katia
K
Borea
Pier Andrea
PA
D058918:Adenosine A3 Receptor Antagonists; D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D000242:Cyclic AMP / Q000096:biosynthesis; D006801:Humans; D011720:Pyrazoles / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D011804:Quinolines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D011869:Radioligand Assay; D051381:Rats; D043684:Receptor, Adenosine A3 / Q000235:genetics; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D014162:Transfection
D058918:Adenosine A3 Receptor Antagonists; D011720:Pyrazoles; D011804:Quinolines; D043684:Receptor, Adenosine A3; D000242:Cyclic AMP