Design, synthesis and pharmacological characterization of coumarin-based fluorescent analogs of excitatory amino acid transporter subtype 1 selective inhibitors, UCPH-101 and UCPH-102.
The excitatory amino acid transporters (EAATs) play a pivotal role in regulating the synaptic concentration of glutamate in the mammalian central nervous system. To date, five different subtypes have been identified, named EAAT15 in humans (and GLAST, GLT-1, EAAC1, EAAT4, and EAAT5, respectively, in rodents). Recently, we have published and presented a structure-activity relationship (SAR) study of a novel class of selective inhibitors of EAAT1 (and GLAST), with the analogs UCPH-101 (IC(50)=0.66μM) and UCPH-102 (IC(50)=0.43μM) being the most potent inhibitors in the series. In this paper, we present the design, synthesis and pharmacological evaluation of six coumarin-based fluorescent analogs of UCPH-101/102 as subtype-selective inhibitors at EAAT1. Analogs 1114 failed to inhibit EAAT1 function (IC(50) values >300μM), whereas analogs 15 and UCPH-102F inhibited EAAT1 with IC(50) values in the medium micromolar range (17μM and 14μM, respectively). Under physiological pH no fluorescence was observed for analog 15, while a bright blue fluorescence emission was observed for analog UCPH-102F. Regrettably, under confocal laser scanning microscopy selective visualization of expression of EAAT1 over EAAT3 was not possible due to nonspecific binding of UCPH-102F.
Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark.
Tri H V
TH
Huynh
Bjarke
B
Abrahamsen
Karsten K
KK
Madsen
Alba
A
Gonzalez-Franquesa
Anders A
AA
Jensen
Lennart
L
Bunch
D001578:Benzopyrans / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D003374:Coumarins / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D015195:Drug Design; D027341:Excitatory Amino Acid Transporter 1 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D057809:HEK293 Cells; D006801:Humans; D020128:Inhibitory Concentration 50; D013329:Structure-Activity Relationship
C579424:2'-amino-7-(diethylamino)-4'-methyl-2,5'-dioxo-5',6',7',8'-tetrahydro-2H,4'H-4,7'-bichromene-3'-carbonitrile; C553295:2-amino-4-(4-methoxyphenyl)-7-(naphthalen-1-yl)-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile; D001578:Benzopyrans; D003374:Coumarins; D027341:Excitatory Amino Acid Transporter 1; D005456:Fluorescent Dyes; C030123:coumarin