Structure-activity relationships of anthraquinone derivatives derived from bromaminic acid as inhibitors of ectonucleoside triphosphate diphosphohydrolases (E-NTPDases).
Reactive blue 2 (RB-2) had been characterized as a relatively potent ectonucleoside triphosphate diphosphohydrolase (E-NTPDase) inhibitor with some selectivity for NTPDase3. In search for the pharmacophore and to analyze structure-activity relationships we synthesized a series of truncated derivatives and analogs of RB-2, including 1-amino-2-sulfo-4-ar(alk)ylaminoanthraquinones, 1-amino-2-methyl-4-arylaminoanthraquinones, 1-amino-4-bromoanthraquinone 2-sulfonic acid esters and sulfonamides, and bis-(1-amino-4-bromoanthraquinone) sulfonamides, and investigated them in preparations of rat NTPDase1, 2, and 3 using a capillary electrophoresis assay. Several 1-amino-2-sulfo-4-ar(alk)ylaminoanthraquinone derivatives inhibited E-NTPDases in a concentration-dependent manner. The 2-sulfonate group was found to be required for inhibitory activity, since 2-methyl-substituted derivatives were inactive. 1-Amino-2-sulfo-4-p-chloroanilinoanthraquinone (18) was identified as a nonselective competitive blocker of NTPDases1, 2, and 3 (K(i) 16-18 muM), while 1-amino-2-sulfo-4-(2-naphthylamino)anthraquinone (21) was a potent inhibitor with preference for NTPDase1 (K(i) 0.328 muM) and NTPDase3 (K(i) 2.22 muM). Its isomer, 1-amino-2-sulfo-4-(1-naphthylamino)anthraquinone (20), was a potent and selective inhibitor of rat NTPDase3 (K(i) 1.5 muM).
Pharmaceutical Institute, Pharmaceutical Sciences Bonn (PSB), Pharmaceutical Chemistry I, University of Bonn, An der Immenburg 4, 53121, Bonn, Germany.
Younis
Y
Baqi
Stefanie
S
Weyler
Jamshed
J
Iqbal
Herbert
H
Zimmermann
Christa E
CE
Müller