Effect of solvent polarity on phenolic antioxidant extraction from Cannabis sativa L. leaves and inflorescences: mixture design optimization and HPLC-DAD/ESI-MS2 profiling.

Cannabis (Cannabis sativa L.) is a source of bioactive compounds with promising applications in the nutraceutical, pharmaceutical, and cosmetic fields. Applying a mixture design approach with three solvents (water, acetone and ethanol), this study investigated how solvent composition modulates the recovery of phenolic compounds from cannabis inflorescences and leaves. Extracts were assessed for total phenolic content (TPC) and antioxidant activities using DPPH, ABTS, FRAP, CUPRAC, and TAC assays, and their chemical profiles were characterized by HPLC-DAD/ESI-MS2. Solvent composition significantly affected extraction efficiency across plant organs. For inflorescences, the highest TPC value (16.05 mg GAE per g dry weight) was obtained with an acetone-enriched mixture (1/6 water-1/6 ethanol-2/3 acetone), whereas leaves reached their maximum (13.65 mg GAE per g DW) with 1/3 ethanol-2/3 acetone. Multi-response optimization identified 1/3 water-1/3 ethanol-1/3 acetone for inflorescences and 50% water-30% ethanol-20% acetone for leaves as the optimal solvent mixtures. HPLC-DAD/ESI-MS2 analysis identified 32 compounds belonging to several classes, including phenolic acids, flavonoids, hydroxycinnamic acid amides, lignanamides, and cannabinoid derivatives. These classes showed diverse content depending on the solvent and plant matrix. The acetone rich mixture produced the highest total cannabinoids (10.56 and 8.45 mg CBN equivalents per g dry weight) for inflorescences and leaves, respectively. These results reveal clear organ and solvent-dependent selectivity in Moroccan Cannabis. These differences were reflected in the antioxidant activities, with extracts showing notable reducing and radical-scavenging capacities across DPPH, ABTS, FRAP, CUPRAC, and TAC assays. These findings support the targeted valorization of cannabis leaves and inflorescences as sources of antioxidant phytochemicals for pharmaceutical and cosmetic applications.