Diabetic retinopathy is the leading cause of blindness which is associated with excessive angiogenesis. Using the structure of wondonin marine natural products, we previously created a scaffold to develop a novel type of antiangiogenesis agent that possesses minimized cytotoxicity. To overcome its poor pharmaceutical properties, we further modified the structure. A new scaffold was derived in which the stereogenic carbon was changed to nitrogen and the 1,2,3-triazole ring was replaced by an alkyl chain. By comparing the bioactivity versus cytotoxicity, compound <b>31</b> was selected, which has improved aqueous solubility and an enhanced selectivity index. Mechanistically, <b>31</b> suppressed angiopoietin-2 (ANGPT2) expression induced by high glucose in retinal cells and exhibited <i>in vivo</i> antiangiogenic activity in choroidal neovascularization and oxygen-induced retinopathy mouse models. These results suggest the potential of <b>31</b> as a lead to develop antiangiogenic small-molecule drugs to treat diabetic retinopathy and as a chemical tool to elucidate new mechanisms of angiogenesis.