Title:Design and Synthesis of 2-substituted [1,2,4]Triazolo[1,5-a]pyrimidines Tethered with Umbelliferone as Selective Carbonic Anhydrase IX and XII Inhibitors
Volume: 25
Issue: 18
Author(s): Romeo Romagnoli*, Elena Romagnoli, Andrea Brancale, Claudiu T. Supuran, Alessio Nocentini, Lorenzo Manfreda, Arianna Zanolli, Roberta Bortolozzi*Giampietro Viola
Affiliation:
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, Ferrara, 44121, Italy
- Laboratory of Experimental Pharmacology,
Istituto di Ricerca Pediatrica (IRP), Fondazione Città della Speranza, Padova, 35128, Italy
- Department of Pharmaceutical and
Pharmacological Sciences, Section of Pharmacology, University of Padova, Padova, 35131, Italy
Keywords:
Carbonic anhydrase inhibitors, coumarin, antiproliferative activity, [1, 2, 4]triazolo[1, 5-a]pyrimidine, isoform selectivity, structure– activity relationship.
Abstract:
Objective: This study presents the design and synthesis of a new series of human carbonic anhydrase
(hCA) inhibitors based on a 5-methyl/phenyl-7-(7’-oxycoumarin)-[1,2,4]triazolo[1,5-a]pyrimidine scaffold.
Methods: The chemical structures of novel coumarin-based triazolopyrimidines 3a-u were confirmed after using
NMR and MS analyses. Their inhibitory profiles were evaluated against a panel of five hCA isoforms. Molecular
docking simulations were conducted to elucidate the binding modes of compounds 3d and 3s with hCA IX and
XII isoforms. Selected derivatives 3d and 3g were tested for their antiproliferative effects on the medulloblastoma
HD-MB03 and the glioblastoma U87MG cell lines. Additionally, compounds 3d and 3g were evaluated alone or
in combination with cisplatin (cis-Pt) for their ability to induce apoptosis in HD-MB03 cells.
Results: In vitro kinetic studies demonstrated that all 5-methyl triazolopyrimidine derivatives (3a-r) selectively
inhibited the tumor-associated hCA isoforms (hCA IX and XII), with KI values ranging from 0.75 to 10.5 μM,
while hCA I, II, IV isoforms were not significantly inhibited (KIs > 100 μM). Compound 3d emerged as the most
potent and selective inhibitor, with KIs of 0.92 and 0.75 μM for hCA IX and XII, respectively. This derivative
significantly suppressed cell proliferation in human brain tumor cell lines, particularly HD-MB03, when it was
studied for its adjuvant effects in combination with cisplatin.
Conclusion: In this study, we have identified compound 3d as a selective inhibitor of the isoforms hCA IX and
XII, showing minimal inhibition over hCA I, II, and IV isoenzymes (selectivity indices > 100). Its moderate inhibitory
effects on hCA IX and XII at submicromolar levels were paralleled by significant antiproliferative activity
against HD-MB03 cells. These findings underscore the potential of compound 3d as a promising candidate for
further therapeutic development, especially in combination with clinically used chemotherapeutic agents.
