Eun Sun Lee, Kyung Y. Yoon
This study investigated the bioactivities of maca (Lepidium meyenii Walp.) leaf extract fractions obtained using deep eutectic solvent (DES)-based ultrasound-assisted extraction (UAE) followed by macroporous resin chromatography.Four fractions (Fr. 1 -Fr.4) were obtained by elution with ethanol of varying concentrations (25%, 50%, 75%, and 100%, v/v), and subsequently total phenolic content (TPC), total saponin content (TSC), and individual phenolic contents as well as their anti-inflammatory, antidiabetic, and antioxidant activity were determined.Pearson correlation analysis revealed that TSC and TPC were strongly associated with biological activities, including 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation scavenging activities, as well as -glucosidase and nitric oxide (NO) inhibitory activities.Fr. 4, characterized by a high TSC (260.95 mg oleanolic acid equivalents (OAE)/g dry weight, DW), exhibited notable anti-inflammatory activity, inhibiting NO production by 36.30% at 60 g/mL.Fr. 3, with TSC of 219.37 mg OAE/g DW and TPC of 53.45 mg gallic acid equivalents (GAE)/g DW, showed strong antidiabetic activity with an IC 50 value of 0.24 mg/mL for -glucosidase inhibition.Fr. 2, enriched in phenolic compounds and with high TPC of 104.78 mg GAE/g DW, demonstrated potent antioxidant activity, with IC 50 values of 0.52 mg/mL and 0.38 mg/mL in DPPH and ABTS assays, respectively.These results indicate that macroporous resin chromatography is effective in obtaining fractions enriched in phenolic compounds and saponins from maca leaf extracts prepared by DES-based UAE, highlighting their potential application as functional food ingredients.