2-Indolinone: An Anticancer Scaffold, Overview of the Studies and Approaches (2017-2024)

2-Indolinone is a versatile scaffold that has been the central moiety in the structure of various drugs. Since the introduction of sunitinib malate, 2-indolinones have been a principal pharmacophoric building block in many drug discovery studies, especially in the last few years. Compounds bearing the 2-indolinone ring system have shown various therapeutic effects, including but not limited to, antidiabetic, antioxidant, anti-inflammatory, anti-HIV, antimicrobial, antipsychotic, antiparkinson, and anticancer activities. Considering that cancer is among the major global causes of death, the antiproliferative activities of these compounds have been the goal of numerous studies. The present review presents an overview of the approaches and advances made during the last eight years (2017-2024) regarding the development of 2-indolinone derivatives within the field of anticancer drug discovery. The derivates gathered herein are classified according to the therapeutic target of the developed compounds, and notable structure-activity relationships as well as significant molecular docking interactions with the target enzymes have been highlighted in each instance. Accordingly, special attention has been paid to reporting derivatives with superior antiproliferative and enzymatic inhibitory effects that have emerged as lead compounds within each respective study.