血管内皮生长因子受体2(VEGFR-2)在各种癌症中是一种治疗干预的动态靶点。本研究旨在探索一种新型的喹喔氮酮衍生物库（如3-呋喃喹喔氮酮羧酰胺、3-吡唑基喹喔啉和3-吡嘧啶基喹喔喹喔啉）对VEGFR-2的抑制活性。其中，6c、7a和7d-f在MTT实验中对HCT-116细胞株和MCF-7细胞株表现出显著的细胞毒性（IC50分别为4.28-9.31μM和3.57-7.57μM），参照标准药物多柔比星(IC50分别为0.72和0.90)。有趣的是，对人胚胎成纤维细胞株WI38的细胞毒性结果显示，这些化合物对HCT-116 (SI分别为8.69-23.19)和MCF-7 (SI分别为9.48-27.80)表现出比多柔比星更高的选择性指数。然后，对这些化合物进行了机制研究，结果显示它们直接抑制了VEGFR-2。值得注意的是，化合物7f的VEGFR-2抑制活性是索拉非尼的1.2倍。通过降低VEGF-A水平来证明了7f的抗血管生成潜力，与对照组相比。同时，它在48小时时的刮痕闭合百分比为61.8%，相比对照组的74.5%，表明化合物7f具有潜在的抗迁移作用。与对照组相比，它使MCF-7细胞的肿瘤抑制基因（p53）的表达增加了近18倍，并使半胱氨酸蛋白酶-3的水平提高了10.7倍。细胞周期分析显示，化合物7f能导致细胞在G2/M期停滞，并显示出预期期的增加，提示其有诱导凋亡的潜力。荧光素V-FITC凋亡结果表明化合物7f的细胞毒性具有凋亡和坏死两种细胞死亡方式。分子对接进一步支持了机制，显示目标化合物与VEGFR-2的活性位点有亲和力。此外，还从ADME性质评估了其物理化学特性和药物样性质。Copyright © 2023 Elsevier Inc. All rights reserved.

Vascular endothelial growth factor receptor-2 is a dynamic target for therapeutic intervention in various types of cancer. This study was aimed at exploring the VEGFR-2 inhibitory activity of a novel library of quinoxalin-2-one derivatives such as 3-furoquinoxaline carboxamides, 3-pyrazolylquinoxalines, and 3-pyridopyrimidyl-quinoxalines. Among them, 6c, 7a, and 7d-f produced remarkable cytotoxicity against HCT-116 (IC50's 4.28-9.31 µM) and MCF-7 (IC50's 3.57-7.57 µM) cell lines using the MTT assay and doxorubicin (DOX) as a reference standard. Interestingly, results of cytotoxicity towards the human fibroblast cell line WI38 revealed that these hits demonstrated higher selectivity indices towards both HCT-116 (SI 8.69-23.19) and MCF-7 (SI 9.48-27.80) than DOX, SI 0.72 and 0.90, respectively. Then, these hits were subjected to a mechanistic study; they showed direct inhibition of VEGFR-2. Impressively, compound 7f displayed 1.2 times the VEGFR-2 inhibitory activity of sorafenib. The antiangiogenic potential of 7f was proved via lowering the level of VEGF-A, than that of control. It as well, exhibited scratch closure percent of 61.8%, compared with 74.5% of control at 48 hrs, indicating the potential anti-migratory effect of the compound 7f. It significantly increased the expression of tumor suppressor gene (p53) on MCF-7 cells by almost 18 folds and upregulated the caspase-3 level by 10.7 folds, compared to the control. Cell cycle analysis revealed cell cycle arrest at G2/M together with a PreG increase which indicated apoptosis induction potential. Annexin V-FITC apoptosis results proposed the two modes of cell death (apoptosis and necrosis) as an inherent mechanism of cytotoxicity of compound 7f. Molecular docking further supported the mechanism showing the affinity of target compounds for VEGFR-2 active site. Moreover, physicochemical and drug-like properties were assessed from the ADME properties.Copyright © 2023 Elsevier Inc. All rights reserved.