Extraction, characterization and antioxidant activities of an acidic polysaccharide from Dendrobium devonianum

Isolation, Structural Characteristics Analysis of a Vigna unguiculata Polysaccharide VUP80-3 and Its Protective Effect on GES-1 Cells In Vitro

Cowpea (Vigna unguiculata) is one of the main edible legume vegetables in China, and it can improve spleen and stomach function. A polysaccharide component (VUP80-3) has been isolated from V. unguiculata in this study. The average molecular weight of VUP80-3 is 6.43 × 10⁴ Da, and the main monosaccharide group is glucose. The mass ratio of monosaccharide groups in the polysaccharide was glucose:galactose:arabinose:rhamnose:xylose:mannose:fucose = 152.36:24.50:16.53:8.13:1.26:0.97:0.82. NMR analysis showed that VUP80-3 has →4)-α-D-Galp (1→ and →4)-α-D-Glcp(1→ main chain and →3,4)-β-D-Glcp(1→, →4,6)-α-D-Glcp(1→ branch chains, and the terminal sugar is α-D-Glcp(1→. Biological activity test results showed that VUP80-3 at 1000 μg·mL^-1 significantly increased the activity of ethanol injured GES-1 cells (p < 0.01) and significantly reduced reactive oxygen species (ROS) in ethanol injured GES-1 cells and inflammatory factors (IL-8, IL-1β and TNF-α,) in GES-1 cells. This compound also reduced the apoptosis rate (p < 0.05), thereby significantly reducing the oxidative damage caused by ethanol in GES-1 cells. Therefore, VUP80-3 is a potential drug to protect the gastric mucosa from damage.

Antibacterial mechanism of polysaccharides from the leaves of Lindera aggregata (Sims) Kosterm. by metabolomics based on HPLC/MS

Lindera aggregata (Sims) Kosterm. is a traditional Chinese herb, which has been proven to have excellent antibacterial activity. In this work, we firstly extracted the polysaccharides from the leaves of Lindera aggregata (Sims) Kosterm. (LLPs), and explored their antibacterial activity and related mechanisms. The experimental results show that LLPs are a good antibacterial agent, which can damage the cell structure of bacteria and lead to the leakage of intracellular lysates. Compared with Escherichia coli (E. coli), LLPs showed better inhibitory activity against Staphylococcus aureus (S. aureus). Furthermore, the administration of LLPs not only led to the upregulation of the levels of fructose-1,6-bisphosphate (F-1,6-P) and citric acid in the glycolysis and tricarboxylic acid cycle pathways in bacteria, but also resulted in the down-regulation of the levels of oxaloacetate (OAA) and 1,3-diphosphoglycerate (1,3-BPG). This study confirmed that LLPs have good antibacterial activity, and broaden the application of the leaves of Lindera aggregata (Sims) Kosterm. in the antibacterial field. It provides ideas for exploring the antibacterial mechanism of active ingredients of Chinese herbal medicine through metabolomics.

Research progress on extraction, purification, structure and biological activity of Dendrobium officinale polysaccharides

Dendrobium officinale Kimura et Migo (D. officinale) is a traditional medicinal and food homologous plant that has been used for thousands of years in folk medicine and nutritious food. Recent studies have shown that polysaccharide is one of the main biologically active components in D. officinale. D. officinale polysaccharides possess several biological activities, such as anti-oxidant, heptatoprotective, immunomodulatory, gastrointestinal protection, hypoglycemic, and anti-tumor activities. In the past decade, polysaccharides have been isolated from D. officinale by physical and enzymatic methods and have been subjected to structural characterization and activity studies. Progress in extraction, purification, structural characterization, bioactivity, structure-activity relationship, and possible bioactivity mechanism of polysaccharides D. officinale were reviewed. In order to provide reference for the in-depth study of D. officinale polysaccharides and the application in functional food and biomedical research.

Water-soluble non-starch polysaccharides of wild-simulated Dendrobium catenatum Lindley plantings on rocks and bark of pear trees

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NSPs with antioxidant activity derived from wild-simulated D. catenatum were analyzed.

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NSP contents depended on the cultured modes and growth periods.

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Facility cultivation provide best growth condition but produce highest ratio of starch.

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While wild-simulated cultivation harvest higher ratio of NSPs, especially in September.

The total water-soluble polysaccharide (TP) of Dendrobium catenatum is composed of starch and active non-starch polysaccharides (NSPs) with glucomannan as the main structural type. Although the TP content has been used as a quality assessment indicator for many years, the NSPs content in samples from different environments and growth seasons have not been reported. In this study, we found that NSPs had stronger antioxidant activity than TP. The NSPs content was higher in wild-simulated environments including rocks and trees compared to plantings grown in greenhouse. The culture mode and growth period affected the ratio of NSPs and starch. Facility cultivation provided optimal growth conditions but produced more starch, whereas wild-simulated cultivation resulted in a higher ratio of NSPs, particularly in September. Therefore, cultivation by lithophytation and epiphytation may be preferable to facility plantings, which is expected to be enormously useful for the current production and quality control of D. catenatum.

Isolation and Purification, Structural Characterization and Antioxidant Activities of a Novel Hetero-Polysaccharide from Steam Exploded Wheat Germ

A purified polysaccharide, designated as SE-WGP_I, was isolated from wheat germ modified by steam explosion. The primary structure characteristics were determined by HPGPC, GC, periodate oxidation-Smith degradation, methylation analysis, FT-IR, NMR and Congo red test. The results showed that SE-WGP_I was a homogeneous hetero-polysaccharide with the average molecular weight of 5.6 × 10³ Da. The monosaccharide composition mainly consisted of glucose, arabinose and xylose with a molar ratio of 59.51: 20.71: 19.77. The main backbone of SE-WGP_I consisted of →4,6)-α-D-Glcp(1→6)-α-D-Glcp(1→3)-β-D-Xylp(1→5)-α-L-Araf(1→ and the side chain was α-D-Glcp(1→ linked at the C4-position of →4,6)-α-D-Glcp(1→. SE-WGP_I likely has a complex netted structure with triple helix conformation and good thermal stability. In addition, SE-WGP_I had valid in vitro radical scavenging activities on DPPH and hydroxyl radicals. This study may provide structural information of SE-WGP_I for its promising application in the fields of functional foods or medicines.