TLC profiles obtained for total alkaloids extracts (Alk) and wash solutions (W): 10 μl of 10 mg/ml solution were deposited. Mobile phase was composed of EtAC/MeOH/H2O (80:12:8). Plates were revealed with Dragendorff's spray reagent (A) or with Dragendorff's reagent following treatment in a NH3-saturated environment before spraying (B).