Antitumor agent-126 (Compound II4) is a photoreactive anticancer compound (IC50 = 0.149) that exhibits significant near-infrared fluorescence emission at 650-760 nm. It demonstrates antiproliferative activity and induces apoptosis upon laser irradiation. This compound effectively inhibits tumor growth in mouse xenograft models when exposed to 650 nm laser light, making it valuable for cancer research.