Significance of metal ion supplementation in the fermentation medium on the structure and anti-tumor activity of Tuber polysaccharides produced by submerged culture of Tuber melanosporum

Optimization for ultrasound combined with flash extraction of polysaccharides from Phyllanthus emblica L. with antioxidant and hyperglycemic activity in vitro

Ultrasound-assisted flash extraction was used to rapidly extract polysaccharides from Phyllanthus emblica L. fruits (PEPs) with a good yield of 9.73 % ± 0.75 %. Furthermore, the PEPs were fractionated by graded precipitation of 30 %, 60 %, and 90 % (v/v) ethanol solution, and the respective molecular weight polysaccharide fractions, namely PEP-30 (166.88 kDa), PEP-60 (109.14 kDa), and PEP-90 (34.59 kDa) were obtained. The three fractions were composed of similar monosaccharides with galacturonic acid as the main constituent. The slope of R.M.S. radius-Mw curve showed that the three polysaccharide fractions were high-branched molecules with solid spherical conformation, and PEP-90 adopted a more compact conformation in aqueous solution. The three polysaccharide fractions had strong antioxidant activity, with PEP-60 showing the strongest antioxidant effect in vitro. PEP-30 (IC50 = 1.56 ± 0.14 mg/mL), PEP-60 (IC50 = 0.99 ± 0.09 mg/mL), and PEP-90 (IC50 = 0.63 ± 0.09 mg/mL) all exhibited mixed-type inhibition of α-glucosidase. Notably, PEP-90 showed the strongest inhibitory effect on α-glucosidase with the strongest binding ability to α-glucosidase and α-glucosidase-substrate complex, which are mainly related to different molecular weight. The results suggest the molecular weight of PEPs had great impact on their biological activities, providing important theoretical guiding for developing Phyllanthus emblica L. food products with the functional activity.

Unveiling the potential of red koji polysaccharides: biosynthesis, extraction, and multifaceted biological activities

Red koji polysaccharides, derived from the fermentation of Monascus, have been recognized for their health-enhancing properties. This article reviews their structural characteristics, biosynthesis pathways, and biological activities. It emphasizes the need for sustainable practices in fermentation and the optimization of extraction methods for scalable production. The significance of exploring the molecular mechanisms involved in their biosynthesis is also highlighted to enhance yield and efficiency. Research indicates that red koji polysaccharides possess diverse biological functions, beneficial for pharmaceutical applications due to their health benefits and minimal toxicity. The review points out the necessity for more detailed studies on key enzymes and genes in biosynthesis to improve production methods. It also identifies the current challenges in production scalability and extraction efficiency. Furthermore, while these polysaccharides show potential in pharmaceuticals, their clinical efficacy and mechanism of action in human subjects require further investigation. The review briefly explores potential structural modifications to improve their biological activities. The review concludes that red koji polysaccharides hold significant untapped potential, particularly in drug formulation. Future research should focus on overcoming current production and application challenges, including conducting clinical trials to validate their efficacy and exploring structural modifications for enhanced therapeutic benefits. This comprehensive understanding of red koji polysaccharides paves the way for their expanded application in the pharmaceutical industry. © 2024 Society of Chemical Industry.

Structural characterization and immunostimulant activities of polysaccharides fractionated by gradient ethanol precipitation method from Panax ginseng C. A. Meyer

Panax ginseng C. A. Meyer is a dual-purpose plant for medicine and food, its polysaccharide is considered as an immune enhancer. Four polysaccharides, WGP-20-F, WGP-40-F, WGP-60-F and WGP-80-F were obtained from ginseng via water extraction and gradient ethanol precipitation with different molecular weights (Mw) of 1.720 × 106, 1.434 × 106, 4.225 × 104 and 1.520 × 104 Da, respectively. WGP-20-F and WGP-40-F which with higher Mw and a triple-helix structure are glucans composed of 4-ɑ-Glcp, do not show remarkable immunoregulatory effects. WGP-60-F and WGP-80-F are heteropolysaccharides mainly composed of 4-ɑ-Glcp and also contain t-ɑ-Araf, 5-ɑ-Araf and 3,5-ɑ-Araf. They are spherical branched conformations without a triple-helix structure and can effectively increase the index of immune organs, lymphocyte proliferation, activate macrophages to regulate the immune system in mice and further enhance immune functions by improving delayed-type hypersensitivity reaction and antibody response. These results indicated that WGP-60-F and WGP-80-F could be used as potential immune enhancers, and gradient ethanol precipitation can be applied for the preparation of ginseng bioactive polysaccharide.

Structural characteristics and gel properties of pectin from citrus physiological premature fruit drop

This study is the first to extract and characterize pectin from citrus physiological premature fruit drop. The extraction yield of pectin reached 4.4 % by acid hydrolysis method. The degree of methoxy-esterification (DM) of citrus physiological premature fruit drop pectin (CPDP) was 15.27 %, indicating it was low-methoxylated pectin (LMP). The monosaccharide composition and molar mass test results showed CPDP was a highly branched macromolecular polysaccharide (β: 0.02, Mw: 2.006 × 10⁵ g/mol) with rich rhamnogalacturonan I domain (50.40 %) and long arabinose and galactose side chain (32.02 %). Based on the fact that CPDP is LMP, Ca²⁺ was used to induce CPDP to form gels. Textural and rheological tests showed that the gel strength and storage modulus of CPDP were higher than commercial citrus pectin (CP) used in this paper due to the lower DM and rich neutral sugar side chains of CPDP. Scanning electron microscope (SEM) results showed CPDP had stable gel network structure.

High-Molecular-Weight Exopolysaccharides Production from Tuber brochii Cultivated by Submerged Fermentation

Truffles are known worldwide for their peculiar taste, aroma, and nutritious properties, which increase their economic value. However, due to the challenges associated with the natural cultivation of truffles, including cost and time, submerged fermentation has turned out to be a potential alternative. Therefore, in the current study, the cultivation of Tuber borchii in submerged fermentation was executed to enhance the production of mycelial biomass, exopolysaccharides (EPSs), and intracellular polysaccharides (IPSs). The mycelial growth and EPS and IPS production was greatly impacted by the choice and concentration of the screened carbon and nitrogen sources. The results showed that sucrose (80 g/L) and yeast extract (20 g/L) yielded maximum mycelial biomass (5.38 ± 0.01 g/L), EPS (0.70 ± 0.02 g/L), and IPS (1.76 ± 0.01 g/L). The time course analysis of truffle growth revealed that the highest growth and EPS and IPS production was observed on the 28th day of the submerged fermentation. Molecular weight analysis performed by the gel permeation chromatography method revealed a high proportion of high-molecular-weight EPS when 20 g/L yeast extract was used as media and the NaOH extraction step was carried out. Moreover, structural analysis of the EPS using Fourier-transform infrared spectroscopy (FTIR) confirmed that the EPS was β-(1-3)-glucan, which is known for its biomedical properties, including anti-cancer and anti-microbial activities. To the best of our knowledge, this study represents the first FTIR analysis for the structural characterization of β-(1-3)-glucan (EPS) produced from Tuber borchii grown in submerged fermentation.

Contribution of Quercetin to the Composition and Antioxidant Properties of Monascus Exopolysaccharides

Exopolysaccharides are important metabolites of Monascus with healthy activities. However, the low production level limits their applications. Hence, the aim of this work was to increase the yield of exopolysaccharides (EPS) and optimize liquid fermentation by adding flavonoids. The EPS yield was optimized via both medium composition and culture conditions. The optional fermentation conditions achieved for EPS production of 7.018 g/L were 50 g/L sucrose, 3.5 g/L yeast extract, 1.0 g/L MgSO₄·7H₂O, 0.9 g/L KH₂PO₄, 1.8 g/L K₂HPO₄·3H₂O, 1 g/L quercetin, and 2 mL/L Tween-80, with pH 5.5, inoculum size 9%, seed age 52 h, shaking speed 180 rpm, and fermentation culture 100 h, respectively. Furthermore, the addition of quercetin increased EPS production by 11.66%. The results also showed little citrinin residue in the EPS. The exopolysaccharides' composition and antioxidant capacity of quercetin-modified exopolysaccharides were then preliminarily investigated. The addition of quercetin changed the composition of the exopolysaccharides and the molecular weight (Mw). In addition, the antioxidant activity of Monascus exopolysaccharides was monitored using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS⁺), and -OH. Monascus exopolysaccharides have good scavenging ability of DPPH and -OH. Furthermore, quercetin increased the scavenging ABTS+ ability. Overall, these findings provide a potential rationale for the application of quercetin in improving the EPS yield.

Immunostimulatory and antioxidant activities of the selenized polysaccharide from edible Grifola frondosa

Grifola frondosa polysaccharide (GFP2) was extracted and purified by anion‐exchange chromatography. A selenized G. frondosa polysaccharide, SeGFP2, was modified in selenylation by nitric acid–sodium selenite (HNO₃‐Na₂SeO₃) method. Structural features were investigated, and the lymphocyte proliferation and antioxidant activities were compared taking GFP2 as control. SeGFP2 with a molecular weight of 2.12 × 10⁴ Da was composed of mannose, glucose, and galactose with a ratio of 3.5:11.8:1.0. A typical absorption of selenium ester was observed in SeGFP2 molecule. SeGFP2 was proposed as a branched polysaccharide, which consisted of 1,3‐D‐Glcp, 1,6‐D‐Glcp, 1,4,6‐D‐Galp, and 1,3,6‐D‐Manp. SeGFP2 showed a linear filamentous structure with some branches. SeGFP2 could significantly promote T‐ or B‐lymphocyte proliferation and the enhancement was higher than GFP2. The in vitro antioxidant activities of SeGFP2 were more potent than GFP2. These present data suggested that selenylation could significantly improve the lymphocyte proliferation and in vitro antioxidant activities of GFP2.

Comparison of the Partial Structure and Antioxidant Activity of Polysaccharides from Two Species of Chinese Truffles

Truffles are world-renowned premium commodities. Due to their unique aroma and rarity, the price of truffles has always been very high. In this study, Diethylaminoethyl anion exchange chromatography and gel filtration were employed for polysaccharide purification from two different species of Chinese truffles. Three polysaccharide fractions were obtained from Tuber panzhihuanense and referred to as TPZ-NP, TPZ-I, and TPZ-II. Additionally, two polysaccharide fractions were purified from T. pseudoexcavatum (TPD-NP and TPD-I). The results of structural elucidation indicated that the polysaccharide from different species showed different monosaccharide composition and linkage units, as well as molecular weight. Two of the polysaccharide fractions with the highest yield, TPZ-I and TPD-I, were chosen for biological testing. The results indicated that both fractions displayed antioxidant properties through mediation of the intestinal cellular antioxidant defense system, which could protect cultured intestinal cells from oxidative stress-induced damage and cell viability suppression. The TPD-I fraction showed stronger antioxidant effects, which may be due to the difference in structure. Further study on the structure-activity relationship is needed to be done.

Alkaline Extraction, Structural Characterization, and Bioactivities of (1→6)-β-d-Glucan from Lentinus edodes

The purpose of this study is to develop a robust approach to obtain β glucans from Lentinus edodes and to characterize their structural and biological properties for sustainable utilization. The alkali extraction was optimized with an orthogonal experimental design, and a concise process for obtaining specific targeting polysaccharides from Lentinus edodes was developed in this study. After purification with a Q-Sepharose Fast Flow strong anion-exchange column, the monosaccharide composition, a methylation analysis, and NMR spectroscopy were employed for their structural characterizations. LeP-N2 was found to be composed of (1→6)-β-d-glucans with minor β-(1→3) glucosidic side chains. Atomic force microscopy (AFM) and high-performance gel permeation chromatography–refractive index–multi-angle laser light scattering (HPGPC-RI-MALLS) also revealed LeP-N2 exhibiting a compact unit in aqueous solution. This (1→6)-β-d-glucan was tested for antioxidant activities with IC₅₀ at 157 μg/mL. Moreover, RAW 264.7 macrophage activation indicated that the release of nitric oxide (NO) and reactive oxygen species (ROS) were markedly increased with no cytotoxicity at a dose of 100 μg/mL. These findings suggest that the (1→6)-β-d-glucans obtained from Lentinus edodes could serve as potential agents in the fields of functional foods or medicine.

Bioactive Mushroom Polysaccharides: A Review on Monosaccharide Composition, Biosynthesis and Regulation

Mushrooms are widely distributed around the world and are heavily consumed because of their nutritional value and medicinal properties. Polysaccharides (PSs) are an important component of mushrooms, a major factor in their bioactive properties, and have been intensively studied during the past two decades. Monosaccharide composition/combinations are important determinants of PS bioactivities. This review summarizes: (i) monosaccharide composition/combinations in various mushroom PSs, and their relationships with PS bioactivities; (ii) possible biosynthetic pathways of mushroom PSs and effects of key enzymes on monosaccharide composition; (iii) regulation strategies in PS biosynthesis, and prospects for controllable biosynthesis of PSs with enhanced bioactivities.

The assessment of anti-tumoral activity of polysaccharide extracted from terrestrial filamentous fungus

Fungal polysaccharides are well-known for the medicinal properties such as antitumor and immunomodulating effects. Hence, this study evaluated antitumor effects of polysaccharide extracted from Fusarium sp. isolated from soil samples of Karaj district, Alborz, Iran along with its taxonomic study. The filamentous fungus strain FK1 was isolated from the soil sample of Karaj, Iran. The strain was identified based on cultural, morphological and 18 S rRNA gene parameters as Fusarium. Further, the strain Fusarium was cultured in fermented broth of modified (PDB) for 10  days at 25 °C. The polysaccharide of strain FK1 was extracted from the mycelium free supernatant by boiling water method and evaluated for antitoxicity effect on two human cancer cell lines: HeLa cell line and Lymphoblastoid cell line (LCL) by MTT method. Findings revealed that water-extracted from mycelia polysaccharide of strain FK1 had the highest cytotoxicity effect against LCL which is the cause of B lymphocyte cancer, at 50  μg/ml concentration dose (114 ± 1.63) followed by 100  μg/ml (105 ± 0.57) and 10  μg/ml (104 ± 0.57), while it did not have a considerable effect on HeLa cell line. Fusarium could be alternative sources as an antitumor component.