Aromatase inhibitory activity of 1,4-naphthoquinone derivatives and QSAR study
A series of 2-substituted amino-3-chloro-1,4-naphthoquinone derivatives (3-12) were synthesized as anticancer agents and tested against four cancer cell lines including HepG2, HuCCA-1, A549 and MOLT-3. The most potent cytotoxic activity against the HepG2, HuCCA-1 and A549 cell lines was found to be m-acetylphenylamino-1,4-naphthoquinone (8) affording IC50 values of 4.758, 2.364 and 12.279 μM, respectively. On the other hand, p-acetylphenylamino-1,4-naphthoquinone (9) exhibited the most potent cytotoxic activity against the MOLT-3 cell line with an IC50 of 2.118 μM. Quantitative structure-activity relationship (QSAR) investigations provided good predictive performance as observed from cross-validated R of 0.9177-0.9753 and RMSE of 0.0614-0.1881. The effects of substituents at the 2-amino position on the naphthoquinone core structure and its corresponding influence on the cytotoxic activity were investigated by virtually constructing additional 1,4-naphthoquinone compounds (13-36) for which cytotoxic activities were predicted using equations obtained from the previously constructed QSAR models. Interpretation of informative descriptors from QSAR models revealed pertinent knowledge on physicochemical properties governing the cytotoxic activities of tested cancer cell lines. It is anticipated that the QSAR models developed herein could provide guidelines for further development of novel and potent anticancer agents.