Extraction, purification and preliminary characterization of polysaccharides from Kadsura marmorata fruits

In this study, response surface methodology and central composite design based on single-factor experiments were applied to the optimization of the extraction parameters (extraction time, extraction temperature, and solid-liquid ratio) of polysaccharides from Kadsura marmorata fruits. The extraction temperature and solid–liquid ratio affected the extraction yield significantly. The optimal conditions included a solid–liquid ratio of 1:27 (mass/volume), an extraction time of 3 h and an extraction temperature of 98 °C. Under these conditions, the maximal yield of crude Kadsura polysaccharide (KPS) was 2.7735 ± 0.068%, which agreed with model predictions. Five major fractions, KPS I, KPS II, KPS III, KPS IV and KPS V, were obtained by diethylaminoethyl (DEAE) cellulose-52 column chromatography. The main fraction, KPS III-1, was isolated from KPS III by Sephadex G-100 column chromatography. Preliminary characterization of KPS III-1 by gas chromatography indicated that it was composed mainly of xylose and galacturonic acid.