Phthalazine Derivatives as VEGFR-2 Inhibitors: Docking, ADMET, Synthesis, Design, Anticancer Evaluations, and Apoptosis Inducers

New phthalazine-derived inhibitors for VEGFR-2 were synthesized for Anticancer evaluations. Also, docking studies were performed to explore the suggested binding orientations of the novel derivatives inside the binding site of VEGFR-2. The achieved biological data were extremely interrelated to that of docking study. In specific, derivative 3f was the greatest effective compound against HepG2 and MCF-7 Cancer cell lines with IC₅₀ = 0.17 ± 0.01 and 0.08 ± 0.01 µM individually. The six highly active derivatives 3b, 3e, 3f, 3g, 6a, and 6b were estimated for their VEGFR-2 inhibitory effects. Derivative 3f was the greatest effective compound which inhibited VEGFR-2 at IC₅₀ = 0.0557 ± 0.002 µM. The activities of 3f were assessed against MCF-7 Cancer cells for Apoptosis induction, cell cycle distribution, and growth inhibition. Compound 3f induced early Apoptosis (21.44%) by more than 36 folds over the control (0.59%). The obtained results showed that compound 3f induced necrotic effect (6.03%) by more than threefolds over the control (1.75%). On the Other hand, compound 3f improved the level of the pro-apoptotic protein; Bax by approximately fivefolds. Moreover, compound 3f noticeably decreased the levels of the anti-apoptotic proteins Bcl-2 by nearly fourfolds in comparison to the control. In addition, derivative 3f remarkably enhanced the Bax/Bcl2 ratio by nearly 18 folds, as compared to the control. Finally, our derivatives 3f, 3g, and 6b revealed good in silico considered ADMET profile in comparing to sorafenib.