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Yi-ching Cheung - One of the best experts on this subject based on the ideXlab platform.
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structure and properties of a 1 3 β d glucan from ultrasound degraded exopolysaccharides of a Medicinal Fungus
Carbohydrate Polymers, 2014Co-Authors: Xia Chen, Ka Chai Siu, Yi-ching CheungAbstract:A high molecular weight (MW) exopolysaccaride (EPS) fraction EPS1 was isolated from the fermentation broth of a Medicinal Fungus Cordyceps sinensis Cs-HK1 and partially degraded by high-intensity ultrasound (US) into a lower MW fraction EPS1U. EPS1U exhibited a single, symmetric peak on size exclusion chromatography with an average MW of 730kDa by light scattering analysis. It had a much lower intrinsic viscosity (1.7 versus 15.6dL/g) but a much higher solubility in water (77.5 versus 5.1g/L) than EPS1. Based on methylation analysis and NMR spectrometry, the structure of EPS1U was deduced as a (1→3)-β-d-glucan with glucose side chains attached to O-6 position at the branching points. EPS1U showed a high moisture absorption capability comparable to chitosan and urea, suggesting its potential as a moisturizing agent for food and cosmeceutical application. This is the first report on a high MW (1→3)-β-d-glucan isolated from EPS produced by Cordyceps sinensis.
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Ultrasonic disruption of fungal mycelia for efficient recovery of polysaccharide-protein complexes from viscous fermentation broth of a Medicinal Fungus.
Ultrasonics sonochemistry, 2014Co-Authors: Yi-ching Cheung, Xing Xun Liu, Qiang WangAbstract:Abstract High-intensity ultrasound (US) was applied to facilitate the extraction of intracellular and extracellular polysaccharide–protein complexes (PSPs) from the viscous mycelial fermentation broth of a Medicinal Fungus Cordyceps sinensis Cs-HK1. The US treatment caused the disruption of fungal mycelia, a dramatic reduction of the apparent broth viscosity, and the release of intracellular products into the liquid medium. The degree of mycelium disruption and the rate of intracellular product release were dependent on US power intensity, treatment period and biomass concentration of broth. The extraction or release kinetics of total water-soluble products and PSPs (yield Y versus time t) under the effect of US was fitted closely to the Elovich model Y = Yo + Y1 ln t and parabolic model Y = Yo + Y1t½, respectively. Another interesting effect of the US treatment was a notable increase in the antioxidant cytoprotective activity of PSP against H2O2 induced cell death.
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Structure and properties of a (1→3)-β-D-glucan from ultrasound-degraded exopolysaccharides of a Medicinal Fungus.
Carbohydrate polymers, 2014Co-Authors: Xia Chen, Ka Chai Siu, Yi-ching CheungAbstract:A high molecular weight (MW) exopolysaccaride (EPS) fraction EPS1 was isolated from the fermentation broth of a Medicinal Fungus Cordyceps sinensis Cs-HK1 and partially degraded by high-intensity ultrasound (US) into a lower MW fraction EPS1U. EPS1U exhibited a single, symmetric peak on size exclusion chromatography with an average MW of 730kDa by light scattering analysis. It had a much lower intrinsic viscosity (1.7 versus 15.6dL/g) but a much higher solubility in water (77.5 versus 5.1g/L) than EPS1. Based on methylation analysis and NMR spectrometry, the structure of EPS1U was deduced as a (1→3)-β-d-glucan with glucose side chains attached to O-6 position at the branching points. EPS1U showed a high moisture absorption capability comparable to chitosan and urea, suggesting its potential as a moisturizing agent for food and cosmeceutical application. This is the first report on a high MW (1→3)-β-d-glucan isolated from EPS produced by Cordyceps sinensis.
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Kinetic models and process parameters for ultrasound-assisted extraction of water-soluble components and polysaccharides from a Medicinal Fungus
Biochemical Engineering Journal, 2013Co-Authors: Yi-ching CheungAbstract:Abstract This study was on the kinetics and process parameters for ultrasound-assisted extraction (UAE) of water-soluble components and polysaccharides (PS) from the dry mycelium of a Medicinal Fungus, Cordyceps sinensis Cs-HK1. Four process variables (factors) were evaluated at different levels, ultrasound intensity (2.44–44.1 W/cm 2 ), temperature (40–70 °C), solid particle size (156.5–750 μm), and solid-to-liquid ratio (1/30–1/70 g/mL). The experimental data of yields versus time in most cases were fitted closely to two empirical kinetic models for solid–liquid extraction, parabolic diffusion equation ( y = y o + y 1 t 1/2 ) and power law ( y = βt n ) with high correlation coefficients ( R 2 ) of 0.95–0.99 for total extract yield, and 0.90–0.96 for PS yield. The PS yield was increased more significantly than the total extract yield with the ultrasound intensity. Reducing the particle size and increasing the extraction temperature led to a higher yield and extraction rate; increasing the solid-to-liquid ratio (or decreasing the liquid volume) increased the PS yield and extraction rate but had little influence on the total extract. Significant correlations were found between extraction rate ( dy/dt ) and ultrasound power density ( P/V ), and between extract yield ( y ) and energy density ( Pt/V ). The kinetic and process parameters are useful for rational design and efficient operation of UAE processes.
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Ultrasonic treatment for improved solution properties of a high-molecular weight exopolysaccharide produced by a Medicinal Fungus
Bioresource technology, 2010Co-Authors: Zhaomei Wang, Yi-ching Cheung, Po-hong LeungAbstract:High-power ultrasound (20 kHz) was applied to modify the physicochemical properties of a high-molecular weight (MW) exopolysaccharide (EPS) from mycelial culture of a Medicinal Fungus. At 35 W/cm(2) or higher ultrasound power, the apparent and intrinsic viscosities of EPS solution dropped by nearly 85% within 10 min, and the water solubility was increased by more than fourfold. The ultrasonic treatment led to a notable reduction of the maximum MW and a more uniform MW distribution, but no significant change in the primary structure of the EPS molecules. In contrast, the intrinsic viscosity of EPS was reduced by only 20% in 1.0M sulfuric acid at 50 degrees C for 9h. Ultrasound was proven an effective and favorable means for improving the solution properties of high-MW bioactive polysaccharides in mild conditions.
Ji-kai Liu - One of the best experts on this subject based on the ideXlab platform.
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Irlactane and Tremulane Sesquiterpenes from the Cultures of the Medicinal Fungus Irpex lacteus HFG1102
Natural products and bioprospecting, 2020Co-Authors: Heping Chen, Tao Feng, Ji-kai LiuAbstract:A new irlactane-type, namely irlactin K (1), and 22 tremulane-type sesquiterpenes including fourteen previously undescribed ones, namely irpexolactins A-N (2-15), and a known irlactane-type sesquiterpenoid, were isolated from the fermentation broth of the Medicinal Fungus Irpex lacteus HFG1102. The structures of all the isolates were characterized by extensive spectroscopic methods, including 1D and 2D NMR and MS spectroscopic analysis. The absolute configurations of irlactin K and the known compound conocenol B (20) were established by single-crystal X-ray diffraction analysis. The vasorelaxant effects of irlactin K (1), irpexolactins A (2), C (4), K (12), and irlactam (22) were evaluated.
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triterpenes with unusual modifications from the fruiting bodies of the Medicinal Fungus irpex lacteus
Phytochemistry, 2019Co-Authors: Ji-kai Liu, Tao Feng, Yang Tang, Zhenzhu Zhao, Heping ChenAbstract:Abstract Ten previously undescribed triterpenoid congeners, namely irpeksolactins A–J, together with eighteen known ones, were isolated from the fruiting bodies of the rainforest-dwelling Medicinal Fungus Irpex lacteus. The structures of all the isolates were characterized by extensive spectroscopic approaches, including 1D & 2D NMR and MS spectroscopic methods. Irpeksolactin J displayed selective and weak cytotoxicity against the human lung cancer cell line A549 and the human hepatocellular carcinoma cell line SMMC-7721.
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irpexolidal represents a class of triterpenoid from the fruiting bodies of the Medicinal Fungus irpex lacteus
Journal of Organic Chemistry, 2019Co-Authors: Ji-kai Liu, Tao Feng, Yang Tang, Zhenzhu Zhao, Heping ChenAbstract:Irpexolidal (1), a triterpenoid with an unprecedented carbon skeleton, along with its biogenetic-related compound irpexolide A (2), were isolated from the fruiting bodies of the Medicinal Fungus Irpex lacteus. Irpexolidal features a 6/5/6/5/6/5-fused polycyclic skeletal system which arises from the eburicane-type triterpene by a 6,7- seco-6,8- cyclo pattern. The structures of 1 and 2 were established by means of extensive spectroscopic techniques, ECD calculation, and DP4+ probability based on GIAO NMR chemical shift calculations. The plausible biosynthetic pathways for compounds 1 and 2 were proposed. Their biological activities were evaluated.
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Irpexolidal Represents a Class of Triterpenoid from the Fruiting Bodies of the Medicinal Fungus Irpex lacteus
2019Co-Authors: Yang Tang, Tao Feng, Zhenzhu Zhao, Heping Chen, Ji-kai LiuAbstract:Irpexolidal (1), a triterpenoid with an unprecedented carbon skeleton, along with its biogenetic-related compound irpexolide A (2), were isolated from the fruiting bodies of the Medicinal Fungus Irpex lacteus. Irpexolidal features a 6/5/6/5/6/5-fused polycyclic skeletal system which arises from the eburicane-type triterpene by a 6,7-seco-6,8-cyclo pattern. The structures of 1 and 2 were established by means of extensive spectroscopic techniques, ECD calculation, and DP4+ probability based on GIAO NMR chemical shift calculations. The plausible biosynthetic pathways for compounds 1 and 2 were proposed. Their biological activities were evaluated
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Irpeksins A-E, 1,10-seco-Eburicane-Type Triterpenoids from the Medicinal Fungus Irpex lacteus and Their Anti-NO Activity
Journal of natural products, 2018Co-Authors: Yang Tang, Tao Feng, Zhenzhu Zhao, Heping Chen, Jian-neng Yao, Ji-kai LiuAbstract:Five new triterpenoids, irpeksins A-E (1-5), were isolated from fruiting bodies of the Medicinal Fungus Irpex lacteus. The structures as well as absolute configurations of the new compounds were established via extensive spectroscopic analysis, computational methods, and Cotton effects. Compounds 1-4 are featured by a scaffold of 1,10- seco- and ring B aromatic eburicane (24-methyllanostane), and compound 5 is characterized by a scaffold of 1,10-9,11- diseco- and ring B aromatic eburicane, which represents unprecedented cleavage patterns in the lanostane family. Compounds 1-5 showed significant inhibitory activity against NO production in LPS-activated RAW 264.7 macrophage cells with IC50 values varying from 2.2 to 19.6 μM.
Guozhu Zhao - One of the best experts on this subject based on the ideXlab platform.
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extraction and antioxidant activity of total triterpenoids in the mycelium of a Medicinal Fungus sanghuangporus sanghuang
Scientific Reports, 2019Co-Authors: Chengshan Cai, Chunrui Han, Yi Jin, Guozhu ZhaoAbstract:The scientific name of the traditional Chinese Medicinal Fungus, Sanghuang, has been clarified and confirmed that it is a new species -Sanghuangporus sanghuang in the recently discovered genus, Sanghuangporus. To maximize the yield of the active ingredients such as the triterpenoids from authentic Sanghuangporus sanghuang, four parameters of the extraction process, including the extraction time, solid–liquid ratio, extraction temperature, and ethanol concentration were determined. The Box–Behnken experimental design and the response surface method were used to optimize the triterpenoid extraction processes of Sanghuangporus sanghuang mycelium. The results showed that the parameters of the triterpenoid extraction processes were not simple linear relationships. Optimum conditions of ultrasonic extraction required an 80% ethanol concentration, a 1:20 solid–liquid ratio, a 20-min extraction time, and a 60 °C extraction temperature, to obtain a maximum triterpenoid extraction of 13.30 mg/g. Antioxidant capacity tests showed that the Sanghuangporus sanghuang triterpenoids had high clearance capabilities for hydroxyl free radicals, superoxide anions, 2,2-diphenyl-1-picrylhydrazyl free radicals, and 2,2’-azinobis-(3-ethylbenzthiazoline-6-sulfonate) radicals, indicating that the Sanghuangporus sanghuang triterpenoids had high antioxidant activities.
Ka Chai Siu - One of the best experts on this subject based on the ideXlab platform.
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Anti-inflammation activity of exopolysaccharides produced by a Medicinal Fungus Cordyceps sinensis Cs-HK1 in cell and animal models
International journal of biological macromolecules, 2020Co-Authors: Ang-xin Song, Ka Chai Siu, Jun Yi Yin, Tak WongAbstract:Abstract This study was to assess the anti-inflammatory potential of exopolysaccharide (EPS) produced by a Medicinal Fungus Cordyceps sinensis Cs-HK1. The EPS was isolated from the Cs-HK1 mycelial fermentation broth by ethanol precipitation and purified by deproteinization and dialysis. The EPS had a total sugar content of 74.8% and a maximum average molecular weight (MW) over 107 Da, and consisted mainly of glucose and mannose, and a small amount of galactose and ribose. In THP-1 and RAW264.7 cell cultures, EPS significantly inhibited lipopolysaccharide (LPS)-induced inflammatory responses of the cells including the release of NF-κB and several pro-inflammatory factors such as NO, TNF-α and IL-1β. In the murine model of LPS-induced acute intestinal injury, the oral administration of EPS to the animals effectively suppressed the expression of major inflammatory cytokines TNF-α, IL-1β, IL-10 and iNOS and alleviated the intestinal injury. The results suggest that the Cs-HK1 EPS has notable anti-inflammatory activity and can be a potential candidate for further development of new anti-septic therapeutics. To the best of our knowledge, this is the first report on the anti-inflammation of an EPS from C. sinensis fungal fermentation.
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Protective effects of exopolysaccharide of a Medicinal Fungus on probiotic bacteria during cold storage and simulated gastrointestinal conditions.
International journal of biological macromolecules, 2019Co-Authors: Ang-xin Song, Ka Chai Siu, Yu Heng Mao, William Chi-shing TaiAbstract:Abstract The efficacy of probiotic health products depends on the capability of the constituent probiotic bacteria to survive through long period of cold storage and the gastrointestinal tract. This study was to evaluate the protective effects of a high-molecular weight (MW) exopolysaccharide (EPS) from a Medicinal Fungus Cs-HK1 on three different bifidobacteria. The EPS had a total dietary fiber content about 70% (w/w), which was close to its total carbohydrate content. It was resistant to artificial gastric acid (pH 2) with no more than 4% (w/w) hydrolysis in 6 h. EPS at 5 g/L significantly increased the survival rate of the probiotic bacteria during cold storage (4 °C) and in simulated gastric acid, reducing the death rate of different bacterial strains by 50% to 70%. The protective effect of EPS was weaker when the concentration was decreased to 3 g/L or when the MW of EPS was reduced by partial degradation with power ultrasound. EPS also showed significantly protective effect on the all bacterial strains in bile juice. The results have demonstrated the potential value of Cs-HK1 EPS as a novel prebiotic fiber for the formulation of synbiotic products with probiotic bacteria.
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Formation and Physiochemical Properties of Silver Nanoparticles with Various Exopolysaccharides of a Medicinal Fungus in Aqueous Solution
Molecules (Basel Switzerland), 2016Co-Authors: Wenjie Jian, Ka Chai Siu, Lu Zhang, Ang-xin SongAbstract:Natural polysaccharides are the most widely used biopolymers for green synthesis of eco-friendly silver nanoparticles (AgNPs). In a previous study, a high molecular weight (MW) fraction of exopolysaccharides (EPS) produced by a Medicinal Fungus Cs-HK1 has been shown useful for green and facile synthesis of AgNPs in water. This study was to further evaluate the effects of molecular properties of EPS on the formation, stability and properties of AgNPs with different EPS fractions at various pH conditions. Three EPS fractions (P0.5, P2.0 and P5.0: MW high to low and protein content low to high) were reacted with silver nitrate at various pH 3.0–8.0 in water. The most favorable pH range was 5.5–8.0 for the formation and stable dispersion of AgNPs. At a given pH, the maximum amount of AgNPs was produced with P5.0, and the minimum with P0.5. The shape, size and physiochemical properties of AgNPs were strongly affected by the molecular characteristics of EPS (MW and conformation). The results may be helpful for understanding the factors and mechanisms for formation of stable AgNPs with natural polysaccharides and the interactions between AgNPs and the polysaccharide hydrocolloids in water.
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Isolation and structure characterization of an antioxidative glycopeptide from mycelial culture broth of a Medicinal Fungus.
International journal of molecular sciences, 2014Co-Authors: Xia Chen, Ka Chai SiuAbstract:A novel glycopeptide (Cs-GP1) with an average molecular weight (Mw) of 6.0 kDa was isolated and purified by column chromatography from the lower Mw fraction of exopolysaccharide (EPS) produced by a Medicinal Fungus Cordyceps sinensis Cs-HK1. Its carbohydrate moiety was mainly composed of glucose and mannose at 3.2:1.0 mole ratio, indicating an O-linked glycopeptide. The peptide chain contained relatively high mole ratios of aspartic acid, glutamic acid and glycine (3.3-3.5 relative to arginine) but relatively low ratios of tyrosine and histidine. The peptide chain sequence analyzed after trypsin digestion by LC-MS was KNGIFQFGEDCAAGSISHELGGFREFREFLKQAGLE. Cs-GP1 exhibited remarkable antioxidant capacity with a Trolox equivalent antioxidant capacity of 1183.8 μmol/g and a ferric reducing ability of 611.1 μmol Fe(II)/g, and significant protective effect against H2O2-induced PC12 cell injury at a minimum dose of 10 μg/mL. This is the first report on the structure and bioactivity of an extracellular glycopeptide from the Cordyceps species.
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An antioxidative galactomannan-protein complex isolated from fermentation broth of a Medicinal Fungus Cs-HK1.
Carbohydrate polymers, 2014Co-Authors: Xia Chen, Wen Qiang Wang, Zhongyang Ding, Ka Chai SiuAbstract:Abstract A protein-containing polysaccharide, EPS2BW, was fractionated from the exopolysaccharide (EPS) produced by a Medicinal Fungus Cordyceps sinensis (Cs-HK1). EPS2BW was mainly composed of galactomannan with about 16% (w/w) protein and 50 kDa average molecular weight. The galactomannan part consisted of mannose and galactose at 1.7:1.0 molar ratio, and the protein segments were composed of sixteen amino acids with 12.5% proline and 16.6% threonine (mol%) being the most abundant. Based on analytical results from NMR, methylation analysis, partial acid hydrolysis and GC–MS, the galactomannan structure was elucidated as a (1 → 2)-α- d -mannopyranosyl (Manp) backbone with O-6-linked galactopyranosyl (Galp) branches. EPS2BW exhibited a high antioxidant capacity in both chemical and cell culture assays, with a Trolox equivalent radical scavenging activity of 44.7 μmol Trolox/mg, a Fe3+ reducing power of 38.9 μmol Fe2+/mg, and significant cytoprotective effect against H2O2-induced PC12 cell death at 50–250 μg/mL.
Tzong-huei Lee - One of the best experts on this subject based on the ideXlab platform.
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Isoprenyl phenolic ethers from the termite nest-derived Medicinal Fungus Xylaria fimbriata
Elsevier, 2019Co-Authors: Mei-chuan Chen, Guei-jane Wang, Yueh-hsiung Kuo, Yin-ru Chiang, Ting-yu Cho, Tzong-huei LeeAbstract:Seven new isoprenyl phenolic ethers, namely fimbriethers A‒G (1‒7), were isolated from the fermented broth of the termite nest-derived Medicinal Fungus Xylaria fimbriata YMJ491. Their structures were determined by spectroscopic data analysis and compared with those reported. The effects of all the isolates at a concentration of 100 μM on the inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS)-induced murine macrophage RAW 264.7 cells were evaluated, and all of them exhibited NO production inhibitory activity with Emax values ranging from 4.6 ± 2.0% to 49.7 ± 0.5% without significant cytotoxicity. In addition, these seven compounds did not alter phenylephrine-induced vasocontraction in isolated intact thoracic aortic rings from C57BL/6J mouse, indicating 1‒7 were not involved in the regulation of endothelial NOS-mediated NO production. Keywords: Xylaria fimbriata, Fimbriether, Isoprenyl phenolic ether, Nitric oxide inhibition, Anti-inflammatio
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Isoprenyl phenolic ethers from the termite nest-derived Medicinal Fungus Xylaria fimbriata.
Journal of food and drug analysis, 2018Co-Authors: Mei-chuan Chen, Guei-jane Wang, Yueh-hsiung Kuo, Yin-ru Chiang, Ting-yu Cho, Tzong-huei LeeAbstract:Abstract Seven new isoprenyl phenolic ethers, namely fimbriethers A‒G (1‒7), were isolated from the fermented broth of the termite nest-derived Medicinal Fungus Xylaria fimbriata YMJ491. Their structures were determined by spectroscopic data analysis and compared with those reported. The effects of all the isolates at a concentration of 100 μM on the inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS)-induced murine macrophage RAW 264.7 cells were evaluated, and all of them exhibited NO production inhibitory activity with Emax values ranging from 4.6 ± 2.0% to 49.7 ± 0.5% without significant cytotoxicity. In addition, these seven compounds did not alter phenylephrine-induced vasocontraction in isolated intact thoracic aortic rings from C57BL/6J mouse, indicating 1‒7 were not involved in the regulation of endothelial NOS-mediated NO production.
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Meroterpenoids from a Medicinal Fungus Antrodia cinnamomea
Journal of natural products, 2017Co-Authors: Mei-chuan Chen, Yueh-hsiung Kuo, Ting-yu Cho, Tzong-huei LeeAbstract:Antrodia cinnamomea, a Medicinal Fungus indigenous to Taiwan, has been shown to exhibit a broad spectrum of bioactivities for the treatments of alcoholic intoxication, diarrhea, abdominal pain, and fatigue, and a number of active principles have been identified. Among the bioactive entities, clinical trials of antroquinonol and 4-acetyl antroquinonol B are being carried out for curing cancer, hypercholesterolemia, and hyperlipidemia. The total synthesis of antroquinonol has been achieved; however, investigating the structure–activity relationship of this class of compounds remained difficult due to the lack of available analogues. Twenty antroquinonols isolated from A. cinnamomea IFS006 are reported herein. Their structures were elucidated using spectral analysis and by comparison with literature values. Of these, 11 antroquinonol analogues, namely, antroquinonols N–X (1–11), were previously unreported. The growth inhibitory activity of all the antroquinonol analogues was evaluated against human A549 and ...