Chemical structure of a novel heteroglycan polysaccharide isolated from the biomass of Ophiocordyceps Sobolifera

Polysaccharides as Quality Marker to Rapid Profile for Ophiocordyceps sinensis by PXRD

BACKGROUND

Ophiocordyceps sinensis has long been recognized as a mysterious and valuable traditional Chinese medicine but there has been little research on quality markers for O. sinensis.

PURPOSE

This study looked into the potential of using powder X-ray diffractometry (PXRD) to analyze polysaccharides as a quality marker for O. sinensis.

STUDY DESIGN

There were 16 different habitats of O. sinensis collected in Qinghai, Gansu, Sichuan, Yunnan, and Tibet. In addition, five different types of Cordyceps species were collected. The characteristic diffraction peaks of O. sinensis were determined and then matched with the characteristic diffraction peaks of intracellular polysaccharides obtained from O. sinensis to determine the attribution relationship of the characteristic diffraction peaks.

METHODS

O. sinensis powder's X-ray diffraction pattern is determined by its composition, microcrystalline crystal structure, intramolecular bonding mechanism, and molecular configuration. After fractionation and alcohol precipitation of crude intracellular polysaccharide, mycelium crude intracellular polysaccharide (MCP) and fruiting body crude intracellular polysaccharide (FCP) were obtained and the fingerprint of O. sinensis was identified by the specific characteristic peaks of the X-ray diffraction pattern from intracellular polysaccharide.

RESULTS

The results indicated that the PXRD patterns of different populations of O. sinensis were overlaid well with 18 characteristic diffraction peaks obtained by microcrystalline diffraction. Moreover, the powder diffractograms as a fingerprint provided a practical identification of O. sinensis from other Cordyceps species. In addition, we detected that the powder diffractograms of intracellular polysaccharide MCP and MCP75 could be coupled with the PXRD of O. sinensis. Specifically, 18 characteristic diffraction peaks were identified as coming from MCP and MCP75 according to those interplanar crystal spacing, which matched well with those of PXRD of O. sinensis.

CONCLUSIONS

PXRD spectra combined with an updated multivariable discriminant model were found to be an efficient and sensitive method for O. sinensis quality control. According to the findings of this study, PXRD should be further investigated for quality control assessments and plant extract selection trials.

Advances in sulfonated modification and bioactivity of polysaccharides

Polysaccharides, as biological macromolecules, are widely found in plants, animals, fungi, and bacteria and exhibit various biological activities. However, many natural polysaccharides exhibit low or non-existent biological activities because of their high molecular weights and poor water solubility, limiting their application in many fields. Sulfonation is one of the most effective chemical modification methods to improve physicochemical properties and biological activities of natural polysaccharides or even impart natural polysaccharides with new biological activities. Therefore, sulfonated polysaccharides have attracted increasing attention because of their antioxidant, anticoagulant, antiviral, and immunomodulatory properties. This paper reviews the recent advances in the sulfonation of polysaccharides, including preparation, characterization, and biological activities of sulfonated polysaccharides, and provides a theoretical basis for wide applications of sulfonated polysaccharides.

Rich d-Fructose-Containing Polysaccharide Isolated from Myxopyrum smilacifolium Roots toward a Superior Antioxidant Biomaterial

The presented study attempts to unveil and evaluate the antioxidant activity of a novel heteropolysaccharide separated from the roots of Myxopyrum smilacifolium (denoted as PS-MSR). The molecular weight of PS-MSR is found to be 1.88 × 10⁴ Da and contains two principal sugars, which are d-glucose and d-fructose, in the backbone. Decoding the structure of the obtained PS-MSR sample has disclosed a novel polysaccharide for the first time. Indeed, the PS-MSR is composed of (1 → 3)-linked glucosyl units and (2 → 3)-linked fructosyl units. In addition, the 1D and 2D NMR spectra of the PS-MSR sample display the repeating unit of the isolated polysaccharide, [→3)-α-d-Glcp-(1 → 3)-β-d-Frucf-(2 → 3)-β-d-Frucf-2 → 3)-)-β-d-Frucf-β-(2→] _n . Interestingly, the PS-MSR sample exhibits outstanding antioxidant activity, signifying the potential utilization of the explored polysaccharide for antioxidant-based material.

Metabolites and Their Bioactivities from the Genus Cordyceps

The Cordyceps genus is a group of ascomycete parasitic fungi, and all known species of this genus are endoparasites; they mainly feed on insects or arthropods and a few feed on other fungi. Fungi of this genus have evolved highly specific and complex mechanisms to escape their host’s immune system and coordinate their life cycle coefficients with those of their hosts for survival and reproduction; this mechanism has led to the production of distinctive metabolites in response to the host’s defenses. Herein, we review approximately 131 metabolites discovered in the genus Cordyceps (including mycelium, fruiting bodies and fungal complexes) in the past 15 years, which can be used as an important source for new drug research and development. We summarize chemical structures, bioactivity and the potential application of these natural metabolites. We have excluded some reports that originally belonged to Cordyceps, but whose taxonomic attribution is no longer the Cordyceps genus. This can and will serve as a resource for drug discovery.

Structural Characterization of Mannoglucan Isolated from Ophiocordyceps sobolifera and Its Antioxidant Activities

A novel polysaccharide structure (PS-T80) was collected from Ophiocordyceps sobolifera biomass and characterized via a combination of chemical and spectral analyses. Employing high-performance gel permeation chromatography (HPGPC), the average molecular weight is proven to be 7.4 × 10⁴ Da. Furthermore, a sugar composition analysis of the obtained polysaccharide suggests two main sugars, β-d-glucose and α-d-mannose, at a molar ratio of 2:1, respectively, in the backbone. The structure analysis unveils that PS-T80 is a mannoglucan, possessing the repeating unit of [→3)-β-d-Glcp-(1 → 3)-α-d-Manp-(1 → 3)-β-d-Glcp-(1→] _n . Such a configuration could be considered a novel polysaccharide. Impressively, in vitro antioxidant tests revealed that PS-T80 has a promising antioxidant activity. These results demonstrate that the obtained PS is a potential bioactive material for biomedical applications.