Evaluating the activity of compounds 1–3 using a zebrafish embryonic development assay: (a) Quantification of 60 hpf zebrafish embryo heartrate. Each square, triangle, circle or diamond represents a single fish and shape definitions are: DMSO, square; 1, triangle; 2, circle; and 3, diamond. Statistics from Student’s t-test (compared to 1% DMSO-treated samples): * p < 0.05, ** p < 0.01, *** p < 0.001 and **** p < 0.0001; (b) Representative images of 75 hpf zebrafish treated with the indicated bonnevillamides; (c) Magnified view of panel (b) highlighting the pericardial edema and abnormal heart morphology.