Uronic acid carbazole assay and cetylpyridinium chloride titration depend on the chondroitin sulfate molecular weight

Quantitative determination of chondroitin sulfate with various molecular weights in raw materials by pre-column derivatization with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate

A simple and reliable HPLC method was developed for quantification of chondroitin sulfate (CS). The procedure is based on precolumn hydrolysis of CS to liberate galactosamine and subsequent derivatization with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate. Hydrolysis and derivatization conditions were optimized. A linear correlation coefficient of 0.9999 was calculated within the range of 10-1500 μg/mL from the standard curve. The method produces good precision and good accuracy (100.75 % recovery). An advantage over other common methods is its ability to quantify CS of all molecular weights and structures, as evidenced by the determination of CS fractions with narrow molecular weight distributions obtained through depolymerization by different methods, while enzymatic HPLC was proven to be infeasible. Extraction recoveries of CS from monosaccharide mixed samples were > 93 %. The reliability was also validated by a small difference (-1.95 % to 4.12 %) relative to enzymatic HPLC results in analysing representative CS samples of different animal origins and suppliers.

Preparation and activity study of Ruoqiang jujube polysaccharide copper chelate

Background: Polysaccharide metal chelate exhibit both immunoregulatory activity and metal element supplementation effects. Methods: In this study, Ruoqiang jujube polysaccharide copper chelate (RJP-Cu) was prepared and the preparation conditions were optimized using the response surface method. Subsequently, RJP-Cu was administered to lambs to evaluate its impact on growth performance, copper ion (Cu2+) supplementation, immune enhancement, and intestinal flora was evaluated. Results: The results indicated that optimal RJP-Cu chelation conditions included a sodium citrate content of 0.5 g, a reaction temperature of 50°C, and a solution pH of 8.0, resulting in a Cu2+ concentration of 583°mg/kg in RJP-Cu. Scanning electron microscopy (SEM) revealed significant structural changes in RJP before and after chelation. RJP-Cu displaying characteristic peaks of both polysaccharides and Cu2+ chelates. Blood routine indexes showed no significant differences among the RJP-Cu-High dose group (RJP-Cu-H), RJP-Cu-Medium dose group (RJP-Cu-M), RJP-Cu-low dose group (RJP-Cu-L) and the control group (p > 0.05). However, compared with the control group, the RJP-Cu-H, M, and L dose groups significantly enhanced lamb production performance (p < 0.05). Furthermore, RJP-Cu-H, M, and L dose groups significantly increased serum Cu2+ concentration, total antioxidant capacity (T-AOC), catalase (CAT), and total superoxide dismutase (T-SOD) contents compared with control group (p < 0.05). The RJP-Cu-H group exhibited significant increases in serum IgA and IgG antibodies, as well as the secretion of cytokines IL-2, IL-4, and TNF-α compared to the control group (p < 0.05). Furthermore, RJP-Cu-H group increased the species abundance of lamb intestinal microbiota, abundance and quantity of beneficial bacteria, and decrease the abundance and quantity of harmful bacteria. The RJP-Cu-H led to the promotion of the synthesis of various Short Chain Fatty Acids (SCFAs), improvements in atrazine degradation and clavulanic acid biosynthesis in lambs, while reducing cell apoptosis and lipopolysaccharide biosynthesis. Conclusion: Thus, these findings demonstrate that RJP-Cu, as a metal chelate, could effectively promote lamb growth performance, increase Cu2+ content, and potentially induce positive immunomodulatory effects by regulating antioxidant enzymes, antibodies, cytokines, intestinal flora, and related metabolic pathways.