Green extraction of mangiferin from Mangifera indica L. cv. Harumanis young leaves using natural deep eutectic solvents by ultrasound-assisted extraction: The potency as antioxidant and antibacterial agent

Agricultural biomass, such as mango leaves, remains underexplored as a source of bioactive compounds despite their high mangiferin content. This study aimed to investigate the use of different NADES compositions, based on choline chloride and betaine as Hydrogen Bond Acceptors (HBAs) and citric acid, lactic acid, and glycerol as Hydrogen Bond Donors (HBDs), for extracting the mangiferin constituent from Harumanis mango (HM) young leaves and investigating total polyphenol content (TPC), total flavonoid content (TFC), and analyzing the in vitro antioxidant and antibacterial properties. The results showed that NADES choline chloride-based, as an HBA, exhibited the highest TPC compared to conventional solvents ( p < 0.05). NADES-4 (choline chloride: glycerol, 1:1,6), and NADES-8 (betaine: glycerol, 1: 1,6), NADES glycerol-based as an HBD, showed comparable results with conventional solvents (50% and 70% ethanol) for the highest TFC ( p > 0.05). Moreover, all NADES solvents, except NADES-7, exhibited a comparable mangiferin content to conventional solvents (50% and 70% ethanol) ( p > 0.05), with values of approximately 47.8, 46.27, and 50.87 mg/g DW, respectively. In addition, NADES-1 demonstrated an inhibitory effect against a gram-negative multidrug-resistant Pseudomonas aeruginosa (MRPA) with a minimum inhibitory concentration (MIC) of 2000 μg/mL, whereas NADES-6 exhibited antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) at 4000 μg/mL. Overall, the findings highlight NADES's potential as a sustainable, low-cost, environmentally friendly solvent for extracting plant-derived bioactive compounds such as mangiferin, with promising applications in the food, pharmaceutical, and nutraceutical industries as a ready-to-use product.