A review on polysaccharides from jujube and their pharmacological activities

Ultrasound-assisted enzymatic extraction of jujube (Ziziphus jujuba Mill.) polysaccharides: Extraction efficiency, antioxidant activity, and structure features

This study investigated the effect of ultrasound-assisted enzymatic extraction (UAEE) on the extraction efficiency, antioxidant activity, and structural properties of jujube polysaccharide (JPS), with hot water extraction (HWE), ultrasound-assisted extraction (UAE), and enzymatic-assisted extraction (EAE) serving as controls. Optimal extraction conditions were determined through a multi-index weighted scoring method that comprehensively accounted for yield, duration, and antioxidant activity. Results demonstrated that the JPS yield obtained by UAEE at 22/33 kHz was 10.5 % to 16.3 % higher than those achieved by the other methods, significantly enhancing antioxidant activity. Monosaccharide composition analysis revealed that UAEE increased the content of key mono-sugars in JPS. Additionally, assessments of molecular weight distribution, zeta potential, and rheological properties showed that UAEE reduced the molecular weight and apparent viscosity of JPS, resulting in a looser structural configuration. These structural modifications were observed in scanning electron microscope (SEM) images, which revealed a filamentous branched morphology in JPS obtained through UAEE. Further observations using the atomic force microscope (AFM) indicated that the polysaccharide chains extracted by UAEE were shorter in length, lower in height, and free from aggregation.

A Homogalacturonan from Peel of Winter Jujube (Zizyphus jujuba Mill. cv. Dongzao): Characterization and Protective Effects against CCl4-Induced Liver Injury

A homogalacturonan pectin (HG, designated as WJP-F80) was extracted from the peel of winter jujube (Zizyphus jujuba Mill. Cv. Dongzao) and separated via ethanol-graded precipitation. The structural and conformational features were elucidated through HPAEC-PAD, GC-MS, 2D NMR, and HPSEC-MALLS studies. In vivo assessments were carried out to evaluate the hepatoprotective effects of WJP-F80 against CCl₄-induced injury of mice. Results showed that WJP-F80 was a linear 1,4-α-galacturonan with partially methyl-esterified at O-6 of GalpA and occasionally acetylation. The Mw of WJP-F80 was determined as 45.3 kDa, the polydispersity was calculated as 1.56, and the Rg was measured as 22.7 nm in 0.1 M NaNO₃. The conformational analysis revealed that WJP-F80 exhibited as rigid stiff chain in low Mw range, while aggregation by self-assembly of HG chains lead to high Mw and random coil conformation. In vivo studies indicated that WJP-F80 can protect the livers of mice from acute injury induced via CCl₄ by decreasing the serum biochemical markers of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) to normal levels. This work provides a theoretical basis for the value-added deep processing of winter jujube.