Background: Currently, aromatase inhibitors (AIs) have been developed for the treatment
of breast cancers and other estrogen-related conditions. However, searching for more and new classes
of AIs is being investigated. 8-Aminoquinoline (8AQ) is an interesting scaffold to be explored. In
particular, 8AQ as its mixed ligands (5-nitrouracil, 5Nu and 5-iodouracil, 5Iu) metal complexes are
potential compounds to be studied.
Objective: Metal complexes of 8AQ-5Nu/5Iu were investigated for aromatase inhibitory activity and
Methods: Metal complexes (1-6) and free ligands were evaluated for aromatase inhibitory and
cytotoxic activities. Aromatase inhibitory activity of the metal complexes was performed according
to a guideline of BD Gentest™ kit using CYP19 enzyme and O-benzyl fluorescein (DBF) as a
substrate. Cytotoxic effect of the compounds was tested against normal embryonic lung cell line
(MRC) using the MTT assay.
Results: Significantly, copper complexes 3 (IC50 = 0.7 μM) and 6 (IC50 = 1.7 μM) were shown to be
active aromatase inhibitors with selectivity indices of 24.74 and16.40, respectively.
Conclusion: Copper complexes of 8AQ-5Nu (3) and of 8AQ-5Iu (6) were highlighted as novel
aromatase inhibitors that could be further developed for therapeutic applications.