artemisinin content was quantified according to Nganthoi and Sanatombi (2019) (link) with slight modifications. Measurements were estimated from 6 samples, each one consisting of a pool of 2 plants. Powdered dry leaf samples (750 mg) were macerated at room temperature for 24 h with 10 ml of toluene. The filtrate was vacuum-dried using a rotary evaporator (Rotavapor® R-200, heating bath B-490, Büchi, Switzerland), and the residue was dissolved in 10 ml of extracting solvent. Then, the extract was washed with an equal volume of NaOH (2% w/v) followed by 4 washes with distilled water. To remove coloured pigments, activated charcoal was added to the extract until the colour disappeared. The filtrate was dried under vacuum and the resulting extract was dissolved in 5 mL of methanol. To prepare the standard curve, artemisinin (purity 98%, purchased from Sigma), was dissolved in methanol.
The derivatisation of artemisinin was made with 100 µl of standard artemisinin or plant extract incubated at 50°C for 30 minutes with 800 µl of 0.2% NaOH (w/v). After allowing the solution to cool to room temperature, 0.2 N HCl was added to bring the final volume to 2 ml for measurement by UV- Spectrophotometry.
The derivatisation of artemisinin was made with 100 µl of standard artemisinin or plant extract incubated at 50°C for 30 minutes with 800 µl of 0.2% NaOH (w/v). After allowing the solution to cool to room temperature, 0.2 N HCl was added to bring the final volume to 2 ml for measurement by UV- Spectrophotometry.