The extraction of polysaccharides using acidic extraction media has been widely explored, demonstrating its usefulness in producing high-yield polysaccharides. However, a higher concentration of acidic solution might break down the structure of polysaccharides, whereas a lower concentration could decrease the extraction efficiency. Despite these difficulties, deep eutectic solvents (DES) have emerged as an alternate extraction medium owing to additional interactions including intermolecular and electrostatic interactions, that could enhance the effectiveness in extraction and biological activities of polysaccharides. The results demonstrated that the microwave-assisted extraction of Micromelum minutum leaf polysaccharide (MMLP) using DES (MMLP-DES) used less microwave power (19.83%) and time (0.78 min less) and produced a higher yield (improvement of 101.20%) than citric acid monohydrate (CAM) (MMLP-CAM). The characteristics of MMLPs significantly altered based on their acidity, molecular weight, morphology, viscosity, degree of esterification, and monosaccharide molar ratio which all affect biological activities. The bioactivities investigation found that MMLP-DES exhibited stronger antioxidant (i.e., DPPH: 74.52% and FRAP: 2.87 mM FeSO4) and anti-hyperglycaemic (e.g., α-amylase inhibition: 86.23%) activities than MMLP-CAM (antioxidant activities: DPPH of 49.33% and FRAP of 1.49 mM FeSO4 and anti-hyperglycaemic activity: α-amylase inhibition of 81.76%) due to their structural changes. This study emphasizes the benefits of DES for extracting polysaccharides with enhanced biological activity for combating oxidative stress and diabetes mellitus.

Muhammad Hasnun Md Yusoff is a 25-year-old PhD candidate in Biochemical Analysis at Universiti Sains Malaysia, having commenced his doctoral studies in March 2024. His research focuses on deep eutectic solvents (DES) for the extraction of bioactive polysaccharides with antioxidants, antidiabetic, and antihypertensive properties. He has published over seven peer-reviewed articles in reputable journals such as Analytica Chimica Acta and International Journal of Biological Macromolecules. He actively contributes to international scientific conferences and serves as a reviewer for academic journals. His work aligns with sustainable health solutions, targeting plant-based therapies for metabolic disorders.