Purification, structural characterization, and hypolipidemic effects of a neutral polysaccharide from Ziziphus Jujuba cv. Muzao

A neutral polysaccharide (PZMP1) with a molecular weight of 16.97 kDa was isolated from Ziziphus Jujuba cv. Muzao with water extraction, ethanol precipitation, and purification with DEAE-Sepharose Fast Flow and Sephacryl S-300 column chromatography. PZMP1 was structurally characterized with high-performance gel-permeation chromatography, gas chromatography, Fourier transform infrared spectroscopy, methylation analysis, NMR spectroscopy, X-ray diffraction, scanning electron microscopy, and atomic force microscopy. The results show that PZMP1 is a homogeneous heteropolysaccharide composed of arabinose, galactose, glucose, mannose, and xylose in a molar percentage of 17.36: 3.29: 2.68: 1.05: 1.00. The majorly backbone of PZMP1 is composed of 1,3,5-linked Araf, 1,3-linked Araf, 1,5-linked Araf, 1,4-linked Glcp, and 1-linked Araf, 1-linked Glcp. According to an NMR analysis, the repeating unit of PZMP1 is a linear backbone with branches at positions O-3, and O-5. PZMP1 also displays effective dose-dependent hypolipidemic activity, suggesting that it is a natural hypolipidemic agent, which could contribute to the functional food qualities of jujube fruit.