Figure 1.

Inhibition of LiARG by chalcone derivatives. LiARG ability to catalyze the conversion of l-arginine into urea was measured in the presence of thirty-six different chalcone derivatives at 100 μM concentration. Quercetin (100 μM) was used as a reference LiARG inhibitor. The control reaction was performed in the absence of any inhibitor. The results are expressed as percentage of LiARG activity taking the enzymatic activity of the control as 100%. A statistical analysis using Student's t-test was performed comparing each chalcone derivative to quercetin (control). P-values < 0.05 (one asterisk), <0.005 (two asterisks) and <0.0005 (three asterisks) were considered significantly different from the control. The dashed lines represent 100% (control) and 50% LiARG activity, which is the cutoff used for selection of the best inhibitors.