Figure 2.

Structure-activity relationships for various sulfanilamide compounds in a seedling growth assay. The sulfanilamide core is shown in the bottom left corner, and specific R-groups for each compound indicated above. Activity assays were performed using Arabidopsis (Col-0) seed plated on solid media containing a range of chemical concentrations. Seedling phenotypes were assessed after 10–14 days of growth. “EC₅₀” indicates the effective concentration of chemical at which 50% of the seedlings were bleached, and “LD₅₀” denotes the concentration that was lethal to 50% of the seedlings. Data represent the mean of two independent experiments. The dendrogram on the left was generated using the ChemMine online structural analysis workbench ( http://bioweb.ucr.edu/ChemMineV2/).