2.1. M. whitei roots treated with ammonia generate an alkaloid artifact
Eight fractions (Alk1 to Alk4 and W1 to W4) of M. whitei roots were tested for their content in alkaloids by TLC with Dragendorff's reagent detection. From these fractions, only Alk2 displayed a potential content in alkaloids, as revealed by spots at retention factors (Rf) 0.52 (bright orange) and 0.90 (pale brown) ( Fig. 1A).