Hyperbranched acidic polysaccharide from green tea

Hyaluronic acid from bluefin tuna by-product: Structural analysis and pharmacological activities

The fishing and aquaculture industries generate a huge amount of waste during processing and preservation operations, especially those of tuna. Recovering these by-products is a major economic and environmental challenge for manufacturers seeking to produce new active biomolecules of interest. A new hyaluronic acid was extracted from bluefin tuna's vitreous humour to assess its antioxidant and pharmacological activities. The characterization by infrared spectroscopy (FT-IR), nuclear magnetic resonance ((1D1H) and 2D (1H COSY, 1H/13C HSQC)) and size exclusion chromatography (SEC/MALS/DRI/VD) revealed that the extracted polysaccharide was a hyaluronic acid with high uronic acid content (55.8 %) and a weight average molecular weight of 888 kDa. This polymer possesses significant anti-radical activity and ferrous chelating capacity. In addition, pharmacological evaluation of its anti-inflammatory and analgesic potential, using preclinical models, in comparison with reference drugs (Dexamethasone, diclofenac, and acetylsalicylate of lysine), revealed promising anti-inflammatory activity as well as interesting peripheral and central antinociceptive activity. Therefore, our new hyaluronic acid compound may therefore serve as a potential drug candidate for the treatment of pain sensation and inflammation of various pathological origins.

Impact of internal metal ions in tea polysaccharides on antioxidant potential and suppression of cancer cell growth

Four kinds of tea polysaccharides (MBTPS, MGTPS, ZBTPS, ZGTPS) were extracted from Maofeng black tea, Maofeng green tea,Ziyan black tea and Ziyan green tea, and then four tea polysaccharides (RMBTPS, RMGTPS, RZBTPS, RZGTPS) after metal removal were prepared. The physicochemical properties, antioxidant activity and inhibitory activity on cancer cell proliferation of the above polysaccharides were studied. The composition analysis shows that these tea polysaccharides were glycoproteins complexes, composed of a variety of monosaccharides, and the removal of metal ions did not lead to fundamental changes in the composition of polysaccharides. In vitro activity, after removing metal ions, the ABTS free radicals scavenging ability and reducing power of tea polysaccharides were decreased, and the inhibitory effect on proliferation of H22 cells weakened. There was a great correlation between metal elements Al and Ni and biological activity. The results showed that the metal ions in tea polysaccharides, especially Al and Ni, had positive effects on biological activity.

Molecular Characterization and Bioactivities of a Novel Polysaccharide from Phyllostachys pracecox Bamboo Shoot Residues

Dietary carbohydrates are unexploited in the by-products of economically valuable Phyllostachys pracecox bamboo shoots. A residue-derived polysaccharide (PBSR1) was aqueously extracted from the processing waste of this bamboo shoot species. Its primary structure and advanced conformation were elucidated by a combined analysis of spectroscopy, chromatography, 2D nuclear magnetic resonance, laser light scattering and atomic microscopy. The results indicated PBSR1 was a triple-helix galactan consisting of →6)-β-D-Galp and →3)-β-D-Galp in linear with an 863 KD molecular weight (M_w). The relationship between the radius of gyration (Rg) and intrinsic viscosity ([η]) on M_w were established as R_g = 1.95 × 10^-2M_w^0.52±0.03 (nm) and [η] = 9.04 × 10^-1M_w^0.56±0.02 (mL/g) for PBSR1 in saline solution at 25 °C, which indicated it adopted a triple-helix chain shape with a height of 1.60 ± 0.12 nm supported by a red shift of λ_max in Congo red analysis. The thermodynamic test (TG) displayed that it had excellent thermal stability for the food industry. Further, those unique structure features furnish PBSR1 on antioxidation with EC₅₀ of 0.65 mg/mL on DPPH· and an ORAC value of 329.46 ± 12.1 μmol TE/g. It also possessed pronounced immunostimulation by up-regulating pro-inflammatory signals including NO, IL-6, TNF-α and IL-1β in murine cells. Our studies provided substantial data for the high-valued application of residues and a better understanding of the structure-function relationship of polysaccharide.

Twelve weeks of treadmill exercise training with green tea extract reduces myocardial oxidative stress and alleviates cardiomyocyte apoptosis in aging rat: The emerging role of BNIP3 and HIF-1α/IGFBP3 pathway

In this study, we consider the effect of treadmill exercise training, green tea extract, and combination of exercise training with green tea extract, in aging rat cardiac myocytes apoptosis markers (i.e., HIF-1α, BNIP3, Bax, IGFBP3, Bcl-2, caspase-3, MDA, GPx, Bax/Bcl-2 ratio, and hematoxylin and eosin). Twenty-four rats (male, Wistar) were divided into four groups: (I) control (n = 6), (II) green tea extract (n = 6), (III) exercise (n = 6), and (IV) exercise + green tea extract (n = 6). Exercise groups performed 12 weeks of running on a rodent treadmill at 17-27 m.min^-1 (60-75% vo2peak) for 5 days per week. Green tea extract involved 300 mg.kg^-1 , 5 days per week for 12 weeks. After being euthanized, the blood and heart were collected for glutathione peroxidase (GPx) activity, malondialdehyde (MDA), HIF-1α, BNIP3, insulin-like growth factor-binding protein-3 (IGFBP3), Bax, Bcl-2, caspase-3, Bax/Bcl-2 ratio, and hematoxylin and eosin level measurements. Compared to control, the ANOVA demonstrated significant effects of green tea extract (F = 14.646 to 32.453, p = .009 to .001, η = 0.295 to 0.715) and exercise training (F = 9.213 to 133.828, p = .007 to .001, η = 0.315 to η = 0.870) on HIF-1a, BNIP3, Bax, IGFBP3, Bcl-2, caspase-3, MDA, GPx, and Bax/Bcl-2 ratio. However, the combination of green tea extract and exercise had no effect on the aforementioned apoptosis markers when compared to isolated green tea extract or isolated exercise (F = 0.002 to 4.068, p = .057 to .968, and η = 0.001 to 0.169). PRACTICAL APPLICATIONS: Isolated exercise training and green tea extract may provide a cardioprotective effect on aging-induced apoptosis through the downregulation of HIF-1α, BNIP3, and IGFBP3 in the heart muscle. However, further research is needed to clarify the effects of combining exercise and green tea.

Isolation, characterization and anticomplementary activity of polysaccharides from the rhizomes of Belamcanda chinensis (L.) DC

The polysaccharides from the rhizomes of Belamcanda chinensis (L.) DC. (BCPs) were obtained by optimal water extraction (extraction temperature 84℃, liquid to solid ratio 42 mL/g and extraction time 100 min), the extraction yield of BCPs was 23.01 ± 0.27% (n=3). Furthermore, two novel polysaccharides (BCP-A1 and BCP-B1) were purified by column chromatography. The BCP-A1 (6.0820×104 kDa) was composed of β -D-Manp-(1→, β -D-Glcp-(1→, →4)-α-D-Galp-(1→ and →3,4)- β-D-Galp-(1→, and BCP-B1 (2.2744×104 kDa) was composed of →5)-α-L-Araf -(1→, β -D-Manp-(1→, β-D-Glcp-(1→, →4)-α-D-Glcp, →4)-α-D-Galp-(1→, →4)-α-D-Galp A-(1→ and →3,4)-β-D-Galp-(1→. In anticomplementary experiments, BCP-A1 (CH50: 0.009 ± 0.003 mg/mL; AP50: 0.015 ± 0.003 mg/mL) and BCP-B1 (CH50: 0.004 ± 0.001 mg/mL; AP50: 0.028 ± 0.005 mg/mL) exhibited potent anticomplementary activity, and acted on C2-, C4- and Factor B components. Our study provides a foundation for BCP-A1 and BCP-B1 as potential complement inhibitors to treat diseases involving with excessive activation of the complement system.

Isolation and Structural Characterization of Two Polysaccharides from Dracocephalum moldavica and Their Anti-Complementary Activity

The two novel polysaccharides, DMP-1 and DMP-2, with molecular weights of 4.1553×10⁵  kDa and 1.9764×10⁵  kDa, respectively, were isolated from Dracocephalum moldavica. The structural characterization indicated that DMP-1 and DMP-2 shared a similar backbone consisting of →5)-Araf-(1→, Manp-(1→, Glcp-(1→, →2)-Manp-(1→, →6)-Glcp-(1→ and →3,6)-Galp-(1→ with a different molar ratios and triple-helix structures with α- and β-type glycosidic bonds. The anti-complementary activity evaluation showed that DMP-1 and DMP-2 had strong complement inhibition through the classical pathway (CP), alternative pathway (AP) and lectin pathway (LP). Mechanistic studies indicated that DMP-1 can block the activation cascade of the complement system by targeting C2, C3, C5, C9, Factor B and Factor P, and that DMP-2 inhibited complement activation by blocking C2, C3, C4, C5, C9 and Factor B.

Strontium based Astragalus polysaccharides promote osteoblasts differentiation and mineralization

Bone formation and repair represent a clinical challenge. In this work, we designed and synthesized strontium Astragalus polysaccharide (APS-Sr), a novel polysaccharide compound that should have therapeutic effects on both anti-inflammation and promoting bone formation. Using material characterization techniques, including SEM, FITR, XRD, etc., we verified the successful synthesis of this compound. Moreover, we examined the potential of this compound for promoting bone repair and inhibiting inflammatory response by cell proliferation assay, ALP and Alizarin Red staining experiments and RT-qPCR. The biological experiment results showed that APS-Sr can effectively inhibit inflammatory factors, promote osteogenic differentiation and up-regulate the bone growth factors. It is therefore believed that APS-Sr should be a promising polysaccharide compound in bone-related biomedical applications.

Improving emulsification properties of alkaline protein extract from green tea residue by enzymatic methods

Alkaline extraction is an important process in the integrated biorefining of leafy biomass to obtain protein, but the resulting alkaline protein extract (APE1) may have poor emulsification properties for food applications. In this study, the components in the APE fractionations obtained by size exclusion chromatography were determined. The emulsification properties of APE were determined using oil/water with a ratio of 7:3. Whey protein and soybean protein isolate were used as controls while enzymes were used to improve APE's emulsification properties. The results showed that the APE could be divided into three fractions with protein content of 83, 56, and 34%. Carbohydrates mainly derived from homogalacturonan pectin were mostly in Fraction 2, while Fraction 3 consisted of peptides, oligosaccharides, and free polyphenols. The APE had similar emulsification capacity and emulsification stability as those of whey protein and soybean isolate. The emulsion made by the APE had a creaming index of 92% with emulsification activity index value of 44 m² g⁻¹, and these numbers could retain after storing at 25 °C for 15 days. The emulsification properties of the APE can be further improved by carbohydrate degradation. With the use of Viscozyme® L, the emulsification activity index value of treated APE was increased by 60%, and then still retained at 67 m² g⁻¹ after storing for 15 days. Treated by either pepsin or alkaline protease, the emulsification properties of APE were decreased, suggesting the key role of protein in APE for emulsification.

•

Alkaline protein extract (APE) had 3 fractions with a fraction of 83% protein. .

•

APE had a creaming index of 92% with EAI of 44 m² g⁻¹ could store for 15⁺ days.

•

APE, whey protein, and soybean protein isolate had similar emulsification property.

•

Emulsification property of APE was attributed from protein and inhibited by pectin.

•

Using Viscozyme® L, EAI of APE emulsion increased by 60% with better stability.

Colanic Acid: Biosynthetic Overproduction by Engineering Escherichia coli and Physical Property Characterization

Colanic acid has promising applications in food, cosmetic, and healthcare fields. In this study, a recombinant WQM003/pRAU was constructed by deleting genes lon and hns and overexpressing genes rcsA and galU in E. coli MG1655Δ(L-Q). After systematic optimization of fermentation conditions, colanic acid yield in WQM003/pRAU reached 19.79 g/L, the highest yield reported so far. The colanic acid produced by WQM003/pRAU was purified and its structure and physical properties were determined. This colanic acid shows a triple-helical structure and is stable up to 102 °C, and its melting temperature is 253.9 °C. This colanic acid shows a sphere-like chain conformation in aqueous solution. The viscosity of this colanic acid solution is related to concentration, shear rate, salt, temperature, and pH. At high concentrations, this colanic acid shows both viscous and elastic behaviors. These results suggest that the colanic acid produced by WQM003/pRAU has broad application prospects.

Influencing Factors on the Physicochemical Characteristics of Tea Polysaccharides

Tea polysaccharides (TPSs) are one of the main bioactive constituents of tea with various biological activities such as hypoglycemic effect, antioxidant, antitumor, and immunomodulatory. The bioactivities of TPSs are directly associated with their structures such as chemical composition, molecular weight, glycosidic linkages, and conformation among others. To study the relationship between the structures of TPSs and their bioactivities, it is essential to elucidate the structure of TPSs, particularly the fine structures. Due to the vast variation nature of monosaccharide units and their connections, the structure of TPSs is extremely complex, which is also affected by several major factors including tea species, processing technologies of tea and isolation methods of TPSs. As a result of the complexity, there are few studies on their fine structures and chain conformation. In the present review, we aim to provide a detailed summary of the multiple factors influencing the characteristics of TPS chemical structures such as variations of tea species, degree of fermentation, and preparation methods among others as well as their applications. The main aspects of understanding the structural difference of TPSs and influencing factors are to assist the study of the structure and bioactivity relationship and ultimately, to control the production of the targeted TPSs with the most desired biological activity.

Preparation and characterization of metal-tea polysaccharide complexes and their inhibition on α-glucosidase

The preparation method and the sources of metal elements may affect the activity of the metal-polysaccharide complex. In this study, four Fe-tea polysaccharide complexes were prepared and three tea polysaccharides (TPSs) from different seasons were extracted. Moreover, the binding mode of TPSs with internal and external metallic elements as well as their inhibitory effect on α-glucosidase was explored. The results revealed that the binding mode (-C-O-Fe and -C-Fe) of the Fe-TPS complex prepared at pH 5.0 was closer to TPS with internal metallic elements. The TPS with the least amount of internal metallic elements (61.72 mg/g) exhibited a high inhibitory activity on α-glucosidase (37.90%). The inhibitory activity of Fe-TPS on α-glucosidase was lower than that without Fe. But the quenching effect and the inhibition type of TPSs on α-glucosidase were not affected by metallic elements. Therefore, the metallic elements have the potential to reduce the hypoglycemic activity of TPS. PRACTICAL APPLICATIONS: In this paper, TPS was extracted from crude tea in different seasons, and the effects of metallic elements in TPS on hypoglycemic activity, physicochemical properties, and structure of TPS were discussed. TPS metal complexes were prepared by adding Fe³⁺ or removing metallic elements, and the differences of internal metallic elements in TPS were discussed. It is of great academic significance to use tea pruned leaves and crude tea as potential resources to develop polysaccharide hypoglycemic products and to reveal the relationship between TPS metal ions and their structure and activity. In addition, it has guiding value for consumers to choose tea-producing regions and growers to choose chemical fertilizer.

Strontium Laminarin polysaccharide modulates osteogenesis-angiogenesis for bone regeneration

Bone regeneration and repair has become one of the major clinical challenges worldwide and it involves multiple processes including inflammation, angiogenesis and osteogenesis. In this study, we synthesized strontium Laminarin polysaccharide (LP-Sr), a novel polysaccharide-metal complex that should have therapeutic effects on modulating osteogenesis and angiogenesis. The structure and composition of the as-fabricated LP-Sr were analyzed by EDS, XRD, FITR, ¹H NMR, HPLC, etc. The results indicate that we successfully synthesized this novel polysaccharide complex. Moreover, we evaluated the biomedical potential of this complex in promoting osteogenesis and angiogenesis by cell proliferation assay, ALP staining, immunofluorescent staining of CD31 and reverse transcription polymerase chain reaction (RT-PCR). The biological experiment results show that LP-Sr can effectively promote proliferation and increase the expression of VEGF and EGFL6 in HUVECs and significantly up-regulate the expression of Col1α1 and OCN in MC3T3-E1. Besides, it is suggested that LP-Sr has positive effects on the suppression of pro-inflammatory factor IL6 in both HUVECs and MC3T3-E1. Moreover, the osteogenic and angiogenic markers, i.e. alkaline phosphatase (ALP) and CD31, exhibited high expression in LP-Sr group. Hence, we believe that LP-Sr should be a promising and novel polysaccharide complex in modulating osteogenesis-angiogenesis for bone regeneration.

Chain conformation of an acidic polysaccharide from green tea and related mechanism of α-amylase inhibitory activity

An acidic tea polysaccharide (TPSA) isolated from green tea was fractionated using a precipitation-fractionation method into seven fractions with different molecular weights. TPSA was characterized as a hyperbranched polysaccharide with a globular homogeneous conformation by analysis of solution parameters of each fraction using static light scattering and viscosity analyses. Observation by transmission electron microscopy confirmed that TPSA occurred as globular homogeneous particles with size in the range of 20-40 nm. To simulate the branched chain segments of TPSA, four model molecules were designed based on chemical structure of TPSA. Molecular docking analysis indicated that the branched chain segments of TPSA similar to the TPSA-4 model molecule showed preferential binding to α-amylase to form the TPSA/α-amylase complex through hydrogen bonding interactions. Circular dichroism spectroscopy showed that the structure of α-amylase was not significantly affected by TPSA. The mechanism of α-amylase inhibitory activity of TPSA was simulated by molecular docking analysis. The branched chain segments of TPSA similar to the TPSA-4 model molecule likely act as a potential competitor to the starch substrate to inhibit the activity of α-amylase.

A neutral polysaccharide from green tea: Structure, effect on α-amylase activity and hydrolysis property

A neutral tea polysaccharide (TPSN) was isolated from green tea. Gas chromatography analysis showed that TPSN was composed of d-glucose, l-arabinose and d-galactose residues at a molar ratio of 90.0: 9.1: 0.9. The weight-averaged molecular weight of TPSN was determined as about 2.0 × 10⁵ g mol^-1 using static light scattering analysis. The result of nuclear magnetic resonance (NMR) spectroscopy indicated that TPSN and water-soluble starch had similar structures. TPSN exhibited inhibitory activity towards α-amylase through the noncompetitive inhibition mechanism, but the tertiary structure of α-amylase related to enzymatic activity, analyzed using circular dichroism spectroscopy, was not affected by TPSN. Meanwhile, TPSN exhibited hydrolysis properties catalyzed by α-amylase. Molecular docking analysis revealed that the various behaviors of TPSN to α-amylase could be attributed to that the different chain segments of TPSN combined with different amino acid residues of α-amylase.

Ultrasonic-Assisted Extraction, Structural Characterization, Chain Conformation, and Biological Activities of a Pectic-Polysaccharide from Okra (Abelmoschus esculentus)

The purpose of this study was to better understand the chemical characteristics and chain conformation of okra polysaccharides extracted by ultrasonic-assisted extraction. A pectic-polysaccharide, named OPP-D, was obtained, which was mainly composed of rhamnose, galacturonic acid, and galactose with a molar ratio of 1.01:1.00:2.31. Combined with NMR analysis, -4)-α-d-GalAp-(1,2,4)-α-l-Rhap-(1- were identified as the backbone with galactan side chains substituted partly at O-4 of Rhap. Molecular weight and radius of gyration of OPP-D were determined as 2.19 × 10⁵ Da and 27.0 nm, respectively. OPP-D was determined as an air-core sphere with branching chains in 0.9% NaCl solution by high-performance size-exclusion chromatography coupled with multi-angle laser light scattering and dynamic light scattering for the first time. Moreover, OPP-D exhibited typical shear-thinning behavior. In addition, OPP-D exhibited remarkable in vitro antioxidant activities and prebiotic activities, while the relatively high molecular weight, high degree of esterification, high content of uronic acids, and highly branched globular conformation of OPP-D might contribute to its in vitro anti-diabetic activities and binding capacities. Results can contribute to a better understanding of the structure–bioactivity relationship of OPPs, and OPP-D has great potential applications in the functional food and pharmaceutical industries.

Chemical Composition and Antioxidant Activities of Polysaccharides from Yingshan Cloud Mist Tea

The study was designed to investigate the chemical composition and antioxidant activities of polysaccharides from Yingshan Cloud Mist Tea. The chemical composition of green tea polysaccharides (GTPS) was analyzed by Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscope (SEM), thermogravimetric (TGA), gas chromatograph (GC), and high-performance gel-permeation chromatography (HPGPC). Then, the antioxidant activities in vitro of GTPS, effects of GTPS on body weight, and the antioxidant activities in chickens were studied. The results showed that GTPS were composed of rhamnose (Rha), arabinose (Ara), xylose (Xyl), mannose (Man), glucose (Glu), and galactose (Gal) in a molar ratio of 11.4 : 26.1 : 1.9 : 3.0 : 30.7 : 26.8 and the average molecular weight was 9.69×104 Da. Furthermore, GTPS exhibited obvious capacity of scavenging DPPH radical, hydroxyl radical, and superoxide radical and enhanced the ferric-reducing power in vitro. Last, GTPS significantly increased the body weight of chickens, enhanced the T-AOC, SOD, and GSH-Px level, and decreased the content of MDA in chickens. The results indicated that GTPS might be a kind of natural antioxidant, which had the potential application in feed industry.

Chemical Composition and Antioxidant Activities of Polysaccharides from Yingshan Cloud Mist Tea

The study was designed to investigate the chemical composition and antioxidant activities of polysaccharides from Yingshan Cloud Mist Tea. The chemical composition of green tea polysaccharides (GTPS) was analyzed by Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscope (SEM), thermogravimetric (TGA), gas chromatograph (GC), and high-performance gel-permeation chromatography (HPGPC). Then, the antioxidant activities in vitro of GTPS, effects of GTPS on body weight, and the antioxidant activities in chickens were studied. The results showed that GTPS were composed of rhamnose (Rha), arabinose (Ara), xylose (Xyl), mannose (Man), glucose (Glu), and galactose (Gal) in a molar ratio of 11.4 : 26.1 : 1.9 : 3.0 : 30.7 : 26.8 and the average molecular weight was 9.69×104 Da. Furthermore, GTPS exhibited obvious capacity of scavenging DPPH radical, hydroxyl radical, and superoxide radical and enhanced the ferric-reducing power in vitro. Last, GTPS significantly increased the body weight of chickens, enhanced the T-AOC, SOD, and GSH-Px level, and decreased the content of MDA in chickens. The results indicated that GTPS might be a kind of natural antioxidant, which had the potential application in feed industry.

Structure, bioactivity and applications of natural hyperbranched polysaccharides

In recent years, hyperbranched polymers, especially the natural hyperbranched polysaccharides (HBPSs), are receiving much attention due to their diverse biological activities and applications. With high degree of branching (DB), HBPSs mainly exist in the form of either a comb-brush shape, dendrimer-like particulate, or globular particle. HBPSs also possess some unique properties, such as high density, large spatial cavities, and numerous terminal functional groups, which distinguish them from other polymers. As a natural biopolymer, HBPS has excellent bioavailability, biocompatibility, and biodegradability, which have versatile applications in the fields of food, medicine, cosmetic, and nanomaterials. In this review, the source and structure of HBPSs from plant, animal, microbial and fungal origins as well as their biological functions and applications are covered, with the aim of further advancing the research of their structure and bioactivity.

Tea Polysaccharides as Potential Therapeutic Options for Metabolic Diseases

Tea polysaccharides (TPS) are regarded as some of the main bioactive constituents of tea made from the leaves and buds of the tea plant ( Camellia sinensis L.). An increasing number of studies have demonstrated that TPS can reduce the risk of type 2 diabetes, obesity, and other metabolic diseases. However, the potential mechanisms responsible for antidiabetic and antiobesogenic activities of TPS remain unclear. Therefore, the cellular and physiological mechanisms that underlie the antidiabetic and antiobesogenic effects, including antioxidant and anti-inflammation effects, inhibition of digestive enzymes, prevention of macronutrient absorption, and expression of gene and protein, were summarized in this review. Furthermore, the gastrointestinal functions of TPS and the role of gut microbiota in the prevention and treatment of metabolic diseases were discussed. It is expected that the present review will be helpful for enhancing our knowledge about the health-promoting effects of TPS on metabolic diseases and stimulating further works on TPS.

Chain conformation and biological activities of hyperbranched fucoidan derived from brown algae and its desulfated derivative

A fucoidan derived from marine brown algae has great potential in biomedical filed. Herein, the fucoidan was successfully isolated and purified by using chitosan microspheres, resulting in the sulfate fucoidan (CF) with degree of sulfation (DS) of 0.94. CF was identified to be highly branched, consisting of fucose (77.4%) and galactose (13.9%), etc., supported by the results of GCMS and light scattering with the structure-sensitive parameter of 0.98 in 0.15 M aqueous NaNO3. The individual CF and its desulfated derivative chains adopted sphere-like conformation in water, observed by atomic force microscopy. CF exhibited higher antiangiogenesis than the desulfated one and strong antileukemia activities through inhibiting cell proliferation and inducing cell apoptosis via cell cycle arrest at G1 phase in vitro. This work provided important information that ester sulfate groups of polysaccharide played an important role in the enhancing of bioactivities of fucoidan, and put forward to a potential drug to treat acute myelocytic leukemia (AML) and tumors.

Chemical Composition and Antioxidant Activities of Polysaccharides from Yingshan Cloud Mist Tea

The study was designed to investigate the chemical composition and antioxidant activities of polysaccharides from Yingshan Cloud Mist Tea. The chemical composition of green tea polysaccharides (GTPS) was analyzed by Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscope (SEM), thermogravimetric (TGA), gas chromatograph (GC), and high-performance gel-permeation chromatography (HPGPC). Then, the antioxidant activities in vitro of GTPS, effects of GTPS on body weight, and the antioxidant activities in chickens were studied. The results showed that GTPS were composed of rhamnose (Rha), arabinose (Ara), xylose (Xyl), mannose (Man), glucose (Glu), and galactose (Gal) in a molar ratio of 11.4 : 26.1 : 1.9 : 3.0 : 30.7 : 26.8 and the average molecular weight was 9.69 × 10⁴ Da. Furthermore, GTPS exhibited obvious capacity of scavenging DPPH radical, hydroxyl radical, and superoxide radical and enhanced the ferric-reducing power in vitro. Last, GTPS significantly increased the body weight of chickens, enhanced the T-AOC, SOD, and GSH-Px level, and decreased the content of MDA in chickens. The results indicated that GTPS might be a kind of natural antioxidant, which had the potential application in feed industry.

Antioxidant Activities and Repair Effects on Oxidatively Damaged HK-2 Cells of Tea Polysaccharides with Different Molecular Weights

This study aims at investigating the antioxidant activity and repair effect of green tea polysaccharide (TPS) with different molecular weights (Mw) on damaged human kidney proximal tubular epithelial cells (HK-2). Scavenging activities on hydroxyl radical (·OH) and ABTS radical and reducing power of four kinds of TPS with Mw of 10.88 (TPS0), 8.16 (TPS1), 4.82 (TPS2), and 2.31 kDa (TPS3) were detected. A damaged cell model was established using 2.6 mmol/L oxalate to injure HK-2 cells. Then, different concentrations of TPSs were used to repair the damaged cells. Index changes of subcellular organelles of HK-2 cells were detected before and after repair. The four kinds of TPSs possessed radical scavenging activity and reducing power, wherein TPS2 with moderate Mw presented the strongest antioxidant activity. After repair by TPSs, cell morphology of damaged HK-2 cells was gradually restored to normal conditions. Reactive oxygen species production decreased, and mitochondrial membrane potential (Δψm) of repaired cells increased. Cells of G1 phase arrest were inhibited, and cell proportion in the S phase increased. Lysosome integrity improved, and cell apoptotic rates significantly reduced in the repaired group. The four kinds of TPSs with varying Mw displayed antioxidant activity and repair effect on the mitochondria, lysosomes, and intracellular DNA. TPS2, with moderate Mw, showed the strongest antioxidant activity and repair effect; it may become a potential drug for prevention and treatment of kidney stones.

Synthesis of cationic branched tea polysaccharide derivatives for targeted delivery of siRNA to hepatocytes

The cationic branched tea polysaccharide (CTPSA) derivative bearing N-acylurea and 3-(dimethylamino)-1-propylamine residues was synthesized and characterized using FTIR and ¹H NMR spectroscopy. A nonspecific siRNA (NsiRNA) was used as a model molecule of functional siRNA that could downregulate over-expressed glycometabolism enzymes in the liver. The result from the agarose gel electrophoresis confirmed that the CTPSA and NsiRNA could form stable complexes when their weight ratio was larger than 18. The zeta potentials and sizes of the complexes were in the range of +8-+15 mv and 120-150 nm, respectively. The CTPSA/NsiRNA complex was observed as nanoparticles with a spherical shape of approximately 100 nm using scanning electron microscopy. The CTPSA derivative and the CTPSA/NsiRNA complexes exhibited lower cytotoxicity in HL-7702 cells when compared with the branched PEI (bPEI) and bPEI/NsiRNA complexes assessed by the Cell Counting Kit-8 assay. The results of flow cytometric analysis and laser confocal microscopy indicated that the CTPSA derivative could effectively target the transfer of the NsiRNA to HL-7702 cells. This work provides a potential approach to promote the CTPSA derivative as a nonviral vector for targeted delivery of functional siRNA to hepatocytes.

Enzyme-Assisted Extraction Optimization, Characterization and Antioxidant Activity of Polysaccharides from Sea Cucumber Phyllophorus proteus

Enzyme-assisted extraction optimization, characterization and in vitro antioxidant activity of polysaccharides from sea cucumber Phyllophorus proteus (PPP) were investigated in the present study. The optimal extraction conditions with a yield of 6.44 ± 0.06% for PPP were determined as follows: Extraction time of 2.89 h, ratio of extraction solvent to raw material of 16.26 mL/g, extraction pH of 6.83, exraction temperature of 50 °C and papain concentration of 0.15%. Three purified fractions, PPP-1a, PPP-1b and PPP-2 with molecular weights of 369.60, 41.73 and 57.76 kDa, respectively, were obtained from PPP by chromatography of FPA98Cl and Sepharose CL-6B columns. Analysis of monosaccharide compositions showed that PPP-1a consisted of N-acetyl-galactosamine (GalNAc), galactose (Gal) and fucose (Fuc), PPP-1b of Fuc as the only monosaccharide and PPP-2 of glucuronic acid, GalNAc and Fuc. Sulfate contents of PPP, PPP-1a, PPP-1b and PPP-2 were determined to be 21.9%, 20.6%, 25.2% and 28.0% (w/w), respectively. PPP and PPP-1a had higher molecular weight and intrinsic viscosity than those of the PPP-1b and PPP-2. PPP, PPP-1a, PPP-1b and PPP-2 exhibited obvious activities of scavenging 1,1-diphenyl-2-picrylhydrazyl radical, hydroxyl radical, superoxide radical and ABTS radical in different extent, which suggested that the polysaccharides from Phyllophorus proteus may be novel agents having potential value for antioxidation.

Interactions between α-amylase and an acidic branched polysaccharide from green tea

To understand the mechanism responsible for the α-amylase inhibitory activity of tea polysaccharides, the interaction between α-amylase and an acidic branched tea polysaccharide (TPSA) was investigated using fluorescence spectroscopy and resonance light scattering analysis. TPSA, exhibiting inhibitory activity towards α-amylase (the maximum inhibition percentage of 65%), was isolated from green tea (Camellia sinensis) and characterized by nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, and gas chromatography. Synchronous fluorescence spectroscopy revealed that the binding interaction between the tryptophan residues of α-amylase and TPSA was predominant. Based on the fluorescence quenching effect of tryptophan residues induced by TPSA, the binding constants between α-amylase and TPSA were determined to be 18.6×10⁶, 8.0×10⁶ and 4.6×10⁶ L·mol^-1 at 20, 30 and 37°C, respectively. The calculated Gibbs free-energy changes were negative, indicating that the bonding interaction was a spontaneous process. The enthalpy and the entropy changes were -62.13 KJ·mol^-1 and -0.0728 KJ·mol^-1·K^-1, suggesting that hydrogen bonding interactions might play a major role in the binding process. The formation of an α-amylase/TPSA complex was evidenced by fluorescence quenching and resonance light scattering analysis, and this complex could be the main contributor to the α-amylase inhibitory activity of TPSA.

Recent advances in tea polysaccharides: Extraction, purification, physicochemical characterization and bioactivities

Tea has a long history of medicinal and dietary use. Tea polysaccharide (TPS) is regarded as one of the main bioactive constituents of tea and is beneficial for health. Over the last decades, considerable efforts have been devoted to the studies on TPS: extraction, structural feature and bioactivity of TPS. However, it has been received much less attention compared with tea polyphenols. In order to provide new insight for further development of TPS in functional foods, in present review we summarize the recent literature, update the information and put forward future perspectives on TPS covering its extraction, purification, quantitative determination techniques as well as physicochemical characterization and bioactivities.

Structural and thermal analysis of a hyper-branched exopolysaccharide produced by submerged fermentation of mushroom mycelium

An exopolysaccharide (PTR-EPS1) purified from the culture medium of the mycelial fermentation of Pleurotus tuber-regium had a weight-average molecular mass of 173.6 kDa and a radius of 55.6 nm.

Structural analysis and anticoagulant activities of the novel sulfated fucan possessing a regular well-defined repeating unit from sea cucumber

Sulfated fucans, the complex polysaccharides, exhibit various biological activities. Herein, we purified two fucans from the sea cucumbers Holothuria edulis and Ludwigothurea grisea. Their structures were verified by means of HPGPC, FT-IR, GC–MS and NMR. As a result, a novel structural motif for this type of polymers is reported. The fucans have a unique structure composed of a central core of regular (1→2) and (1→3)-linked tetrasaccharide repeating units. Approximately 50% of the units from L. grisea (100% for H. edulis fucan) contain sides of oligosaccharides formed by nonsulfated fucose units linked to the O-4 position of the central core. Anticoagulant activity assays indicate that the sea cucumber fucans strongly inhibit human blood clotting through the intrinsic pathways of the coagulation cascade. Moreover, the mechanism of anticoagulant action of the fucans is selective inhibition of thrombin activity by heparin cofactor II. The distinctive tetrasaccharide repeating units contribute to the anticoagulant action. Additionally, unlike the fucans from marine alga, although the sea cucumber fucans have great molecular weights and affluent sulfates, they do not induce platelet aggregation. Overall, our results may be helpful in understanding the structure-function relationships of the well-defined polysaccharides from invertebrate as new types of safer anticoagulants.