This study aims to acetylate Rehmannia glutinosa polysaccharides by acetic anhydride method, optimize process parameters and evaluate their antioxidant activity. With the degree of substitution(D_s) as a criterion, the effects of reaction time, acetic anhydride-to-polysaccharides ratio and temperature were investigated. Process parameters were optimized by single-factor experiment and response surface methodology. The infrared spectroscopy(IR) and scanning electron microscopy(SEM) proved the successful acetylation and were employed to preliminarily analyze the structural characteristics of acetylated derivatives. The results showed that the D_s was 0.327 under the optimal technological conditions, including m(acetic anhydride):m(R. glutinosa polysaccharides)=2.70, reaction time 3.0 h and temperature 48 ℃. Further, the antioxidant properties of acetylated derivatives were investigated in vitro and acetylation was found effective to improve the antioxidant activity of R. glutinosa polysaccharides. This study provides a reference for the further development and application of R. glutinosa polysaccharides.
Acetylation ; Antioxidants/pharmacology* ; Polysaccharides/pharmacology* ; Rehmannia/chemistry*

Dendrobii Caulis are commonly used tonic Chinese medicinal materials with a long history of application. As demonstrated by pharmacological results, the chemical constituents and the extracts of Dendrobii Caulis have anti-inflammatory, antibacte-rial, antioxidant, and anti-tumor effects, and can also regulate immunity, lower blood pressure, and regulate blood sugar. The active ingredients contained are widely concerned by scholars. This paper comprehensively summarized the chemical constituents and pharmacological activities of Dendrobium plants reported so far. The chemical constituents isolated from Dendrobium plants are mainly alkaloids, sesquiterpenoids, flavonoids, fluorenones, coumarins, bibenzyls, phenanthrenes, lignans, steroids, phenols, and polysaccharides. This paper is expected to provide a reference for further research, development, and utilization of Dendrobium plants.
Alkaloids ; Antioxidants/pharmacology* ; Dendrobium ; Flavonoids ; Polysaccharides/pharmacology*

An absorbable hemostatic material based on polysaccharide was prepared. The concentration of blood cells and coagulation factors was increased by reducing the water content in the blood, so as to reduce the coagulation time and achieve the purpose of rapid hemostasis. The specific surface area of starch was increased by using hydrochloric acid to hydrolyze potato starch, which made it easier to combine with α-amylase and increased the degradation rate. Starch was crosslinked into microspheres by crosslinking agent, which made the particle size uniform and greatly improved the water absorption. The surface modification of crosslinked starch microspheres with carboxymethyl group can further improve the water absorption of hemostatic materials. The results showed that the water absorption rate of our hemostatic material was more than 800%, and the average hemostatic time in the animal model was 138.7s. Compared with the imported products on the market, our hemostatic material have better hemostatic performance.
Animals ; Hemostasis ; Hemostatics/pharmacology* ; Polysaccharides/pharmacology* ; Starch/pharmacology* ; Water/pharmacology*

Hypolipidemic polysaccharides have notable activity and safety with a range of diverse sources. In this paper, the classification of hypolipidemic polysaccharides was carried out into polysaccharide sulfate, glycosaminoglycan, homopolysaccharide and heteropolysaccharide. The hypolipidemic activity mechanism and structure-activity relationship hypothesis of those polysaccharides in recent years were briefly reviewed therefore to provide references for the study and product development of polysaccharides.
Hypolipidemic Agents ; chemistry ; pharmacology ; Polysaccharides ; chemistry ; pharmacology ; Structure-Activity Relationship

This study aimed to characterize the chemical composition of a new sulfated polysaccharide from the red alga Gracilaria chouae and evaluate its activation effects on RAW264.7 macrophages. It showed that the obtained G. chouae polysaccharide (GCP-3A) was a sulfated acidic polysaccharide with a molecular weight of 11.87 kDa. GCP-3A was composed of xylose, galactose, glucose, and mannose with a molar ratio of 3.00:29.28:0.63:0.45, and it contained α,β‍-glycosidic linkages. Scanning electron microscopy (SEM) and a Congo red test showed that it was a heterogeneous polysaccharide with irregular interwoven sheets and rods, and did not have a triple-helix conform‍ation. Furthermore, GCP-3A significantly promoted the proliferation of RAW264.7 macrophages and the secretion of nitric oxide (NO) in tests of 3-‍(4,‍5-dimethylthiahiazo-2-yl)‍-2,‍5-diphenytetrazoliumromide(MTT) and NO.
Gracilaria/chemistry* ; Macrophages ; Molecular Weight ; Polysaccharides/pharmacology* ; Sulfates/pharmacology*

Alzheimer Disease ; metabolism ; Animals ; Antioxidants ; metabolism ; Mice ; Polysaccharides ; pharmacology

Animals ; Diabetic Nephropathies ; drug therapy ; Dioscorea ; chemistry ; Polysaccharides ; pharmacology ; Rats

OBJECTIVETo investigated the chemical structures and bioactivity of polysaccharides from Isatidis Radix.

METHODPolysaccharides were extracted and purified by column chromatograph and their chemical structures were identified by UV, IR, NMR, periodic acid oxadation and Smith degradation method and their stimulation effects to macrophage were evaluated by using MTT method.

RESULTFive polysaccharides, polysaccharide A , B, C, D and E were gotten and their molecular weights were 2 000, 1 757.1, 1 34 2.7, 955.6, 11.7 kDa, respectively. Polysaccharide A was composed of arabinose, polysaccharide E was composed of arabinose and galactose, polysaccharides B, C, D were composed of glucose and 1 --> 2, 1 --> 3, 1 --> 4, 1 --> 6 linkages existed in polysaccharides A-E, of A, B, C, D, E were alpha-configurations. Polysaccharides B, C and D showed better bioactivity than polysaccharides A and E with stimulation index (SI) of 5.31, 4.76, 5.17.

CONCLUSIONFive polysaccharides are seperated firstly from Isatidis Radix.

Intestinal microecology is an important defense system in the human body. The intestinal flora is the core micro-ecosystem in the human intestine. It has a symbiotic relationship with the overall functions of the body. It has strong metabolic activity to maintain the normal functioning of the body and resist the invasion of various viral antigens in the body. Playing a protective function,the imbalanced intestinal microecology can cause various diseases. Polysaccharides can be extracted from a wide range of sources and have low toxicity and side effects. They have attracted wide attention because of their anti-tumor, anti-oxidant, anti-inflammatory and other biological activities. Studies have demonstrated that polysaccharides can regulate intestinal microecological disorders. According to the studies in recent years, this review summarizes that polysaccharides mainly modulate intestinal microecological disorders through regulating the composition of intestinal flora, improving the metabolism of the flora, and repairing the intestinal tract barrier. On the basis of these mechanisms of action, this paper elaborates the anti-tumor, immunomodulatory, and anti-inflammatory activities of polysaccharides. This paper can provide reference for the future research on the intestinal microecology-regulating mechanism and biological activities of polysaccharides.
Anti-Inflammatory Agents ; Ecosystem ; Gastrointestinal Microbiome ; Humans ; Intestines ; Polysaccharides/pharmacology*

The flower of Hibiscus syriacus has good ornamental and edible-medicinal values.In this study,four samples of two varieties,namely white multiple petals flower and pink multiple petals flower,were selected as test materials.And the optimum extraction conditions,relative molecular weight,monosaccharide composition and antioxidant activity of polysaccharides in flower were investigated.Through single factor experiment and response surface,the optimal extract conditions of polysaccharide were designed as follows:extraction temperature at 96.8℃,ratio of material to liquid of 43.5∶1 m L·g~(-1),extraction time of 3.1 h.Polysaccharides of H.syriacus flowers were analyzed by high performance gel chromatography.The average molecular masses of the 4 polysaccharide samples were1.49×10~5,1.25×10~5,1.01×10~5,1.37×10~5,respectively.Polysaccharides of H.syriacus flowers were mainly composed of glucose,mannose,galactose,rhamnose and arabinose by pre-column derivatization HPLC.The ratio of galactose was the highest in five monosaccharide,and the ratio of galactose to glucose was 1.656-4.496.In addition,crude polysaccharides of H.syriacus flowers showed potential antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl radical(DPPH)assay,total reducing capacity assay and ABTS assay in vitro,and its antioxidant effect showed a good dose-effect relationship with the concentration of crude polysaccharides.Among the tested varieties,polysaccharides of pink multiple petals flower and white multiple petals flower had the same molecular masses and monosaccharides composition,but the antioxidant activity of the polysaccharides of pink multiple petals flower was higher than that of the white flowers.The results of this study can provide a theoretical basis for the application of H.syriacus flower in the field of functional foods.
Antioxidants ; chemistry ; pharmacology ; Flowers ; chemistry ; Hibiscus ; chemistry ; Monosaccharides ; chemistry ; Phytochemicals ; chemistry ; pharmacology ; Pigmentation ; Polysaccharides ; chemistry ; pharmacology