Extraction, Structural Characteristics, and Antioxidant Activity of a Glucose-Dominated Polysaccharide, NJPW,...

With the hypothesis that Nardostachys jatamansi polysaccharides (NJPs) could be the functional constituent contributing to the pharmacological effects of N. jatamansi, this study comprehensively examined the extraction approach, chemical characteristics, and antioxidant activities of the polysaccharide from N. jatamansi. An ultrasonic-assisted extraction method was developed, with the critical optimum parameters determined as follows: ultrasonic temperature at 64 °C, solid-liquid ratio of 1:45, and ultrasonic time of 52 min. Through purification, a pure N. jatamansi polysaccharide (NJPW) was obtained, and its structure was characterized. The monosaccharides of NJPW mainly included glucose, arabinose, and galactose, with a molar weight of 21.907 kDa. NJPW exhibited irregular sheet-like structures, demonstrating the characteristic FTIR and NMR spectra of polysaccharides. NJPW mainly contained the α-d-glucan structure, which was primarily composed of an →4-glcp-(1→ linkage. NJPW exhibited practical activity to scavenge DPPH•, OH•, and ABTS•⁺ radicals as well as a protective effect against oxidative damage in human cells by decreasing MDA content and enhancing SOD activity. Collectively, the findings of this study expanded the phytochemical understanding of the therapeutic application of N. jatamansi and provided a natural antioxidant for further medicinal research and potentially drug development under various oxidative damage conditions.