Extraction optimisation and structural elucidation of an anti-tumour polysaccharide from eupatorium fortunei turcz

Response surface methodology was employed to optimise ultrasonic-assisted extractions technique of crude polysaccharide from the aerial parts of Eupatorium fortunei Turcz. based on a three-level, three-variable Box-Behnken design. The optimal extraction parameters were determined to be a water-to-raw material ratio of 34, an extraction time of 30 min and an ultrasonic power of 400 W. Yield was 2.12 ± 0.15%. Crude polysaccharide was purified and decolourised. The purified polysaccharide (EFP) was elucidated via IR spectra, revealing characteristic fructofuranose. GC-MS analysis indicates that EFP composed of glucose, fructose and galactose with molar ratios of 2.90:4.26:0.93. MTT assay in HeLa cancer cells revealed EFP inhibited cell viability in a dose-dependent manner at different concentrations of EFP (12.5, 25, 50 and 100 μg/mL), with an IC₅₀ value of 31.50 μg/mL. These findings indicate that EFP holds promise as a plant polysaccharide for anticancer therapy.