In vivo screening of compounds 1–5 in zebrafish embryos. Representative micrograph of embryos at 3 days poster fertilization, which were treated with compounds 1–5. The zebrafish embryos treated with compounds 2, 3, and 5 developed normally, and there were no obvious differences in morphology and growth between control and treated embryos. The zebrafish embryos treated with >200 µM of 1, however, had cardiac edema and cardiac hypertrophy (black arrow). The zebrafish embryos treated with compound 4 developed normally but were found dead on day 2. All the images are in same magnification, scale is 200 µm.