High-performance liquid chromatography of reducing carbohydrates as strongly ultraviolet-absorbing and electrochemically sensitive 1-phenyl-3-methyl-5-pyrazolone derivatives

Predominant secretion of cellobiohydrolases and endo-β-1,4-glucanases in nutrient-limited medium by Aspergillus spp. isolated from subtropical field

Biological degradation of cellulose from dead plants in nature and plant biomass from agricultural and food-industry waste is important for sustainable carbon recirculation. This study aimed at searching diverse cellulose-degrading systems of wild filamentous fungi and obtaining fungal lines useful for cellooligosaccharide production from agro-industrial wastes. Fungal lines with cellulolytic activity were screened and isolated from stacked rice straw and soil in subtropical fields. Among 13 isolated lines, in liquid culture with a nutrition-limited cellulose-containing medium, four lines of Aspergillus spp. secreted 50–60 kDa proteins as markedly dominant components and gave clear activity bands of possible endo-β-1,4-glucanase in zymography. Mass spectroscopy (MS) analysis of the dominant components identified three endo-β-1,4-glucanases (GH5, GH7 and GH12) and two cellobiohydrolases (GH6 and GH7). Cellulose degradation by the secreted proteins was analysed by LC-MS-based measurement of derivatized reducing sugars. The enzymes from the four Aspergillus spp. produced cellobiose from crystalline cellulose and cellotriose at a low level compared with cellobiose. Moreover, though smaller than that from crystalline cellulose, the enzymes of two representative lines degraded powdered rice straw and produced cellobiose. These fungal lines and enzymes would be effective for production of cellooligosaccharides as cellulose degradation-intermediates with added value other than glucose.

Protective Effect of Fucoidan against MPP+-Induced SH-SY5Y Cells Apoptosis by Affecting the PI3K/Akt Pathway

The main pathologic changes of the Parkinson’s disease (PD) is dopaminergic (DA) neurons lost. Apoptosis was one of the important reasons involved in the DA lost. Our previous study found a fucoidan fraction sulfated heterosaccharide (UF) had neuroprotective activity. The aim of this study was to clarify the mechanism of UF on DA neurons using human dopaminergic neuroblastoma (SH-SY5Y) cells a typical as a PD cellular model. Results showed that UF prevented MPP⁺-induced SH-SY5Y cells apoptosis and cell death. Additionally, UF pretreated cells increased phosphorylation of Akt, PI3K and NGF, which means UF-treated active PI3K–Akt pathway. Moreover, UF treated cells decreased the expression of apoptosis-associated protein, such as the ratio of Bax/Bcl-2, GSK3β, caspase-3 and p53 nuclear induced by MPP⁺. This effect was partially blocked by PI3K inhibitor LY294002. Our data suggested that protective effect of UF against MPP⁺-induced SH-SY5Y cells death by affecting the PI3K–Akt pathway. These findings contribute to a better understanding of the critical roles of UF in treating PD and may elucidate the molecular mechanisms of UF effects in PD.

Pyrazolone ligation-mediated versatile sequential bioconjugations

Bioconjugation chemistries are critical tools in biotherapeutics discovery. The past efforts have been exclusively focused on two-segment conjugations. However, emerging research directions, such as polypharmacy biotherapeutics, desire multiple-component bioconjugations where more than two pharmacologically related biomolecules can be assembled into a single construct in high efficiency. We present here a set of sequential bioconjugation chemistries centered on a pyrazolone structural motif. It starts with a clickable “pyrazolone ligation” between a hydrazine group and a β-ketoester moiety followed by the conjugation between the newly formed pyrazolone core and an aldehyde-bearing biomolecule through a Knoevenagel reaction forming a Michael addition acceptor that can effectively capture a thiol-bearing biomolecule. When utilized intermolecularly, it quickly assembles four segments together forming a quadruple functional construct. When applied intramolecularly, it offers a set of highly diverse biomolecule scaffolds including stapled peptides and poly-macrocyclic peptides. We envision broad utilities of such sequential ligation chemistries.

A multiple component sequential bioconjugation chemistry establishes upon the joined force of hydrazine, β-keto ester, thiol and aldehyde.

The structural characterization and immune modulation activitives comparison of Codonopsis pilosula polysaccharide (CPPS) and selenizing CPPS (sCPPS) on mouse in vitro and vivo

Codonopsis pilosula polysaccharide (CPPS) and selenizing CPPS (sCPPS) were prepared and identified by a combination of chemical and instrumental analysis. Their immune modulation activities were compared by lymphocyte proliferation and flowcytometry tests in vitro or serum antibody responses and cytokines with immunization against OVA mice in vivo. The results showed that the sCPPS was successfully modified in selenylation. In vitro, the sCPPS were more effective compared with CPPS in promoting lymphocyte proliferation synergistically with PHA or LPS and increasing the ratio of CD4+ to CD8 + T cells. In vivo, sCPPS could significantly raised IgG, IgM, IFN-γ, IL-2 and IL-4 contents in the serum of mouse against OVA in comparison with CPPS. These results indicate that selenylation modification can enhance the immune modulation activitives of CPPS. sCPPS would be as a component drug of new-type immunoenhancer.

Ulvan lyase assisted structural characterization of ulvan from Ulva pertusa and its antiviral activity against vesicular stomatitis virus

Marine green algae are valuable sources of diverse health-promoting bioactive components. Ulvan is suitable for biological applications due to its unique structure and numerous bioactivities. Here, the complex structure of ulvan from Ulva pertusa was analyzed using specific ulvan lyase degradation, MS, and NMR detection. Its structure mainly consists of →4)-β-d-GlcA-(1 → 4)-α-l-Rha3S-(1 → and →4)-β-d-Xyl-(1 → 4)-α-l-Rha3S-(1 → repeating units. Small amounts of →4)-α-l-IdoA-(1 → 4)-α-l-Rha3S-(1 → unit also exist. In addition, a minor number of branches, a single GlcA, and a long branch containing GlcA-Glc were linked to Rha3S. The antiviral activity of the ulvan and its degraded fragments were further investigated. Ulvan (1068.2 kDa) and ulvan-F1 (38.5 kDa) with relatively high molecular weight showed potency of inhibiting the infection and replication of vesicular stomatitis virus (VSV) at 100 μg/mL, the inhibition rate of VSV replication was 40.75% and 40.13%, respectively. These results indicated that ulvan has potential as a functional agent.

Development of a RP-HPLC method for determination of glucose in Shewanella oneidensis cultures utilizing 1-phenyl-3-methyl-5-pyrazolone derivatization

A method was developed and validated for low-level detection of glucose. The method involves quantitation of glucose though derivitization with 1-phenyl-3-methyl-5-pyrazolone (PMP) and HPLC-DAD analysis. The developed method was found to be accurate and robust achieving detection limits as low as 0.09 nM. The applicability of the method was tested against microbial samples with glucose acting as a carbon fuel source. The method was shown to be able to accurately discriminate and quantify PMP-glucose derivatives within Shewanella oneidensis MR-1 samples. The method proved capable at examining glucose usage during the early hours of microbial growth, with detectable usage occurring as early as two hours. S. oneidensis cultures were found to grow more effectively in the presence of oxygen which coincided with more efficient glucose usage. Glucose usage further increased in the presence of competing electron acceptors. The rate at which S. oneidensis reached exponential growth was affected by the presence of ferric iron under microaerobic conditions. Such samples reached exponential growth approximately two hours sooner than aerobic samples.

Antioxidant, Hypolipidemic and Hepatic Protective Activities of Polysaccharides from Phascolosoma esculenta

The aims of this study were to investigate the antioxidant, hypolipidemic and hepatic protective effects of Phascolosoma esculenta polysaccharides (PEP). PEP was prepared from Phascolosoma esculenta by enzyme hydrolysis and its characterization was analyzed. The antioxidant activities of PEP were evaluated by the assays of scavenging 1,1-Diphenyl-2-picrylhydrazyl (DPPH), superoxide anion, hydroxyl radicals and chelating ferrous ion in vitro. It showed that PEP could scavenge radicals effectively and had favorable antioxidant activities. In the meantime, the hypolipidemic effect of PEP was investigated in vivo by using mice model fed with high-fat diet with or without PEP treatment. Compared with the hyperlipidemic mice without treatment, the serum levels of total cholesterol (TC) (30.1–35.7%, p < 0.01), triglyceride (TG) (24.5–50.8%, p < 0.01 or p < 0.05), low-density lipoprotein cholesterol (LDL-C) (49.6–56.8%, p < 0.01) and liver levels of TC (21.0–28.4%, p < 0.01), TG (23.8–37.0%, p < 0.01) decreased significantly, whereas serum high-density lipoprotein cholesterol (HDL-C) (47.7–59.9%, p < 0.01 or p < 0.05) increased significantly after treatment with different dosage of PEP (0.2, 0.4 and 0.8 g per kg body weight, respectively). In addition, superoxide dismutase (SOD) (10.2–22.2% and 18.8–26.9%, p < 0.05), glutathione peroxidase (GSH-Px) (11.9–15.4% and 26.6–30.4%, p < 0.05) activities in serum and liver enhanced markedly while aspartate aminotransferase (AST) (18.7–29.6% and 42.4–58.0%, p < 0.05), alanine transaminase (ALT) (42.7–46.0% and 31.2–42.2%, p < 0.05) activities, as well as the levels of malondialdehyde (MDA) (15.9–24.4% and 15.0–16.8%, p < 0.01 or p < 0.05) in serum and liver reduced markedly. Moreover, the histopathological observation of livers indicated that PEP could attenuate liver cell injury. The animal experimental results demonstrated that PEP exerted hypolipidemic and hepatoprotective roles in hyperlipidemic mice. In summary, our results above suggest that PEP might be a potential natural antioxidant and utilized as a therapeutic candidate for hyperlipidemia.

Purification of N- and O-glycans and their derivatives from biological samples by the absorbent cotton hydrophilic chromatographic column

Mass spectrum (MS) is one of the most commonly used tools for qualitative and quantitative analysis of glycans. However, due to the complexity of biological samples and the low ionization efficiency of glycans, these need to be purified and derivatized prior to MS analysis. Existing purification strategies require a combination of multiple methods and are cumbersome to operate. Here, we propose a new method for the purification of glycoprotein N/O-glycans and their derivatives using a hand-packed absorbent cotton hydrophilic interaction chromatography column (HILIC). The method's reliability and applicability were verified by purifying N/O-glycans and the derivatives of standard glycoproteins, such as chicken albumin and porcine stomach mucin. Stable isotope labelling was used to compare the glycans' recovery following different purification methods. Absorbent cotton HILIC was also successfully applied for the analysis of human serum and fetal bovine serum glycoprotein N-glycans. Finally, testing revealed high binding capacity (9 mg/g^-1 maltohexaose/absorbent cotton) and good recovery (average recovery was 91.7%) of glycans. Compared with traditional procedures, the proposed purification method offers considerable advantages, such as simplicity, high efficiency, economy, universality, and broad applicability for the pretreatment of glycans and their derivatives in biological samples prior to MS analysis.

Icodextrin Degradation Products in Spent Dialysate of CAPD Patients and the Rat, and its Relation with Dialysate Osmolality

Objective

Peritoneal dialysis (PD) with a 7.5% icodextrin-containing dialysis solution provides prolonged ultra-filtration compared with glucose-based dialysis solutions. Colloid osmosis is the most likely mechanism, but studies in rats suggest it is caused by an increase in osmolality due to degradation of icodextrin. Therefore, human spent dialysate was analyzed with high-performance liquid chromatography (HPLC) using gel permeation size-exclusion chromatography. An increasing peak (with a low molecular weight, < 1000 Da) was observed during the dwell. The aim of this study was to quantitate breakdown products of icodextrin (which could explain this peak) and investigate whether there was a relationship with dialysate amylase concentration and dialysate osmolality.

Design

Long-dwell effluents (dwell time 9.15 – 14.30 hours) obtained from 12 PD patients using a 7.5% ico-dextrin solution during the night were analyzed. The following icodextrin breakdown products were measured: maltotetraose (G4), maltotriose (G3), maltose (G2), and glucose (G1). In 6 of these patients, the sugars maltoheptaose (G7), maltohexaose (G6), and maltopentaose (G5) were also determined in both effluent and plasma. In addition, G4, G3, G2, and G1 were measured in four Wistar rats during a 6-hour dwell study.

Results

In the human studies, the median distribution of the sugars in the effluent was G4, 6.7%; G3, 16.5%; G2, 23.1%; and G1, 53.5%. The osmolality in spent dialysate ranged between 288 and 326 mOsm/kg H2O. The median contribution of the sugars G2 – G4 was 5.4 mOsm/kg H2O. No correlation was present between dialysate osmolality and duration of the dwell ( r = –0.04, p = 0.91); nor was there a relation between the concentration of G2 and duration of the dwell ( r = 0.50, p = 0.10). No relationship was found between the amount of amylase and the concentration of G2 in the effluent ( r = 0.49, p = 0.10), nor between the total concentration of the sugars G2 – G4 in the spent dialysate and dialysate osmolality ( r = –0.31, p = 0.33). However, a strong correlation was seen between urea concentration and osmolality ( r = 0.85, p < 0.001), and also between sodium concentration and dialysate osmolality in the spent dialysate ( r = 0.92, p < 0.0001). The levels of the sugars G2, G3, and G4 in effluent were higher than in unused dialysate, but lower than or similar to plasma levels. Concentrations of the sugars G5, G6, and G7 were lower in spent dialysate than in unused dialysate, and higher than in plasma. In the rat study, dialysate osmolality increased with the duration of the dwell. A clear relationship was present between osmolality and concentration of the sugars G2 – G4 in the effluent. The median amount of amylase in the effluent was 1252 U/L.

Conclusion

A 7.5% icodextrin-based dialysis solution used during the long exchange caused only a slight increase in dialysate osmolality in humans. The osmolality at the end of the dwell in the human situation was dependent mainly on concentrations of the small solutes urea and sodium in the effluent. The contribution of icodextrin degradation products was marginal. In the rat, however, a clear relationship was present between osmolality and icodextrin degradation products in spent dialysate, explaining the increased dialysate osmolality at the end of the dwell. The difference between the two species can be explained by the very high amylase concentrations in the rat, leading to a rapid degradation of icodextrin. The rat is therefore not suitable to study peritoneal fluid kinetics using icodextrin as an osmotic agent.

Degradation of different molecular weight fucoidans and their inhibition of TGF-β1 induced epithelial-mesenchymal transition in mouse renal tubular epithelial cells

In order to investigate the anti-fibrotic effect of different molecular weight (Mw) fucoidans on TGF-β1-induced mouse renal tubular epithelial cell (MTEC) mode. Oxidative degradation method was used to obtain fucoidans with different molecular weights and the reaction time, reaction temperature and the concentration of oxidants were investigated. Cell viability was detected by CCK-8, and EMT markers expression was detected by Western-bolt and Cell immunofluorescence assay. As a result, after chemical analysis of three independent batches of prepared samples, one batch of fucoidan sample (LHX 1-9) which chemical contents are similar but Mw ranging from 3.3 KDa to 49.3 KDa were selected to do further research. We found LHX1 (Mw = 3.3 KDa) and LHX 3-9 (Mw = 6.6 KDa, 8.3 KDa, 11.3 KDa, 14.9 KDa, 25.2 KDa, 35.4 KDa, 49.3 KDa) could resist the TGF-β1-induced depithelial-mesenchymal transition (EMT) by decreased expression of Fn and CTGF and maintained epithelial cell morphology in MTEC. However, the relationship between the Mw of fucoidans and their anti-EMT effect is not simply linear. Among the samples, LHX 1, 5 and 8 showed significant anti-EMT effects than others by de-regulated Fn and CTGF expression on MTEC cells.

In vitro antioxidant, antibacterial, in vivo immunomodulatory, antitumor and hematological potential of exopolysaccharide produced by wild type and mutant Lactobacillus delbureckii subsp. bulgaricus

Biological evaluation of exopolysaccharides (EPS) produced by wild type and mutant Lactobacillus delbureckii (EPSWLD and EPSMLD) was investigated. Varying degrees of functional groups associated with polysaccharides were present thus confirming the EPS. The EPSs had strong antioxidant potential in a dose dependent (0.5–10 mg/mL) manner. EPSWLD and EPSMLD exhibited the highest 1,1-diphemy 1-2-picryl-hydrazyl (DPPH) activity (73.4 % and 65.6 %), total antioxidant activity (1.80 % and 1.42 %), H₂O₂ scavenging activity (88.5 % and 78.6 %) and Ferric Reducing Antioxidant Power (FRAP) (1.89 % and1.81 %) at 10 mg/mL respectively. WLD and MLD were highly susceptible to chloramphenicol, cotrimoxazole, tetracycline, erythromycin and ceftazidine and resistant to cefuroxime, gentamicin and cloxacillin. The EPSs had antibacterial activity against the test pathogens. B. subtilis and S. aureus had the highest susceptibility (26.0 mm and 23.0 mm). EPSMLD modulate the highest IgG, IgA and IgM production (68–126 mg/dL and 67–98 mg/dL and 64–97 mg/dL) in the treated tumor induced mice (TTIM). EPSWLD and EPSMLD exhibited reduction capability on the CEA level (3.99–4.35 ng/L and 4.12–4.23 ng/L) of the TTIM. EPSWLD TTIM had the highest amount of RBC, WBC and PCV (5.6 × 10¹²%, 68000% and 42%). The EPS increased the lifespan of TTIM. In conclusion EPSWLD and EPSMLD had strong biological potential with pharmacological and neutraceutical activity.

Combinatory high-resolution microdissection/ultra performance liquid chromatographic-mass spectrometry approach for small tissue volume analysis of rat brain glycogen

Cyto-architectural diversity of brain structures emphasizes need for analytical tools for discriminative investigation of distinctive neural structures. Glycogen is the major energy reserve in the brain. There is speculation that brain utilization of this fuel source may affect detection of hypoglycemia. To evaluate sex-specific regulation of glycogen mass and mobilization in the glucose-sensory ventromedial hypothalamic nucleus (VMN), current research coupled UHPLC-electrospray ionization mass spectrometric (LC-ESI-MS) analysis capabilities with novel derivatization protocols for high-sensitivity measurement of glucose and glycogen in small-volume neural tissue samples. This work also sought to demonstrate utility of pairing this approach with optimized Western blot methods for measurement of glycogen metabolic enzyme protein expression. Here, high-resolution micropunch dissection tools for discriminative isolation of VMN tissue were used in conjunction with newly developed glycogen analytical methods and an experimental treatment paradigm for intra-cranial hindbrain-targeted administration of estrogen receptor-alpha (ERα) or -beta (ERβ) receptor antagonists to address the hypothesis that estradiol activates one or both hindbrain ER populations to exert sex-specific regulatory effects on VMN glycogen mass and hypoglycemia-associated mobilization. Outcomes validate a novel multi-analytical platform for investigation of in vivo sex-dimorphic regulation of glycogen metabolism in precisely-defined brain elements under conditions of energy balance versus imbalance. This combinatory approach will facilitate ongoing efforts to elucidate effects of acute versus chronic hypoglycemia on glycogen metabolism in characterized brain glucose-sensory loci and determine effects local glycogen mass and/or mobilization adaptions on sensory monitoring and signaling of recurring hypoglycemia in each sex.

Effects of Intracerebroventricular Glycogen Phosphorylase Inhibitor CP-316,819 Infusion on Hypothalamic Glycogen Content and Metabolic Neuron AMPK Activity and Neurotransmitter Expression in Male Rat

Brain glycogen is a vital energy source during metabolic imbalance. Metabolic sensory neurons in the ventromedial hypothalamic nucleus (VMN) shape glucose counter-regulation. Insulin-induced hypoglycemic (IIH) male rats were infused icv with the glycogen breakdown inhibitor CP-316,819 (CP) to investigate whether glycogen-derived fuel controls basal and/or hypoglycemic patterns of VMN gluco-regulatory neuron energy stability and transmitter signaling. CP caused dose-dependent amplification of basal VMN glycogen content and either mobilization (low dose) or augmentation (high dose) of this depot during IIH. Drug treatment also prevented hypoglycemic diminution of tissue glucose in multiple structures. Low CP dose caused IIH-reversible augmentation of AMPK activity and glutamate decarboxylase (GAD) protein levels in laser-microdissected VMN GABA neurons, while the higher dose abolished hypoglycemic adjustments in these profiles. VMN steroidogenic factor-1 (SF-1) neurons exhibited suppressed (low CP dose) or unchanged (high CP dose) basal SF-1 expression and AMPK refractoriness of hypoglycemia at each dose. CP caused dose-proportionate augmentation of neuronal nitric oxide synthase protein and enhancement (low dose) or diminution (high dose) of this profile during IIH; AMPK activity in these cells was decreased in high dose-pretreated IIH rats. CP exerted dose-dependent effects on basal and hypoglycemic patterns of glucagon, but not corticosterone secretion. Results verify that VMN GABA, SF-1, and nitrergic neurons are metabolic sensory in function and infer that these populations may screen unique aspects of neurometabolic instability. Correlation of VMN glycogen augmentation with attenuated hypoglycemic VMN gluco-regulatory neuron AMPK activity implies that expansion of this fuel reservoir preserves cellular energy stability during this metabolic threat.

Generation of a highly attenuated strain of Pseudomonas aeruginosa for commercial production of alginate

Alginate is an important polysaccharide that is commonly used as a gelling agent in foods, cosmetics and healthcare products. Currently, all alginate used commercially is extracted from brown seaweed. However, with environmental changes such as increasing ocean temperature and the increasing number of biotechnological uses of alginates with specific properties, there is an emerging need for more reliable and customizable sources of alginate. An alternative to seaweed for alginate production is Pseudomonas aeruginosa, a common Gram-negative bacterium that can form alginate-containing biofilms. However, P. aeruginosa is an opportunistic pathogen that can cause life-threatening infections in immunocompromised patients. Therefore, we sought to engineer a non-pathogenic P. aeruginosa strain that is safe for commercial production of alginate. Using a homologous recombination strategy, we sequentially deleted five key pathogenicity genes from the P. aeruginosa chromosome, resulting in the marker-free strain PGN5. Intraperitoneal injection of mice with PGN5 resulted in 0% mortality, while injection with wild-type P. aeruginosa resulted in 95% mortality, providing evidence that the systemic virulence of PGN5 is highly attenuated. Importantly, PGN5 produces large amounts of alginate in response to overexpression of MucE, an activator of alginate biosynthesis. The alginate produced by PGN5 is structurally identical to alginate produced by wild-type P. aeruginosa, indicating that the alginate biosynthetic pathway remains functional in this modified strain. The genetic versatility of P. aeruginosa will allow us to further engineer PGN5 to produce alginates with specific chemical compositions and physical properties to meet different industrial and biomedical needs.

Parallel On-Target Derivatization for Mass Calibration and Rapid Profiling of N-Glycans by MALDI-TOF MS

Glycosylation is an important post-translational modification of proteins, and abnormal glycosylation is involved in a variety of diseases. Accurate and rapid profiling of N-glycans by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) is still technically challenging and hampered mainly by mass drift of instrument, manual identification of spectrum peaks, and poor cocrystallization with traditional matrices besides low ionization efficiency of analytes. In the present study, a parallel on-target derivatization strategy (POTDS), on the basis of two rationally combined matrices, i.e., 3-hydrazinobenzoic acid plus DHB (DHB/3HBA) and quinoline-3-carbohydrazide plus DHB (DHB/Q3CH), was proposed for mass calibration and rapid detection of reducing N-glycans. Both DHB/3HBA and DHB/Q3CH show high derivatization efficiency and can improve the ionization efficiency of reducing N-glycans significantly. For mass calibration, in combination with dextrans, DHB/3HBA and DHB/Q3CH prove to be highly sensitive matrices facilitating both MS and MS² calibration for N-glycans in dual polarities. For rapid identification, the regular mass difference observed for each N-glycan labeled with Q3CH and 3HBA respectively can eliminate the occurrence of false positives and promote automated identification of N-glycans in complex samples. For relative quantitation, the acid-base pair of DHB/Q3CH generates a concentrated cocrystallization of glycan-matrix mixtures at the edge of the droplet uniformly, exhibiting good linearity (R² > 0.998) and accuracy (RSD ≤ 10%). Furthermore, the established POTDS was successfully utilized to assess N-glycans of serum from HCC patients, revealing potential for biomarker discovery in clinical practice.

Preparation of chondroitin sulfates with different molecular weights from bovine nasal cartilage and their antioxidant activities

Biological functions of chondroitin sulfate, including anti-oxidation and anti-inflammation, are associated with its molecular weight. This study aimed to evaluate the correlation between antioxidant activity and molecular weights of chondroitin sulfate derived from bovine nasal cartilage (BCS). BCS extracted by compound enzymatic method was further purified via DEAE-cellulose column separation to obtain BCS-II (129.4 kDa), which was further degraded by H₂O₂-Vc to obtain four subfractions: BCS-II-1 (92.7 kDa), BCS-II-2 (54.1 kDa), BCS-II-3 (26.3 kDa), and BCS-II-4 (19.7 kDa). Changes in the physicochemical properties of BCS-II before and after degradation were compared via FT-IR, NMR and monosaccharide composition analysis. Finally, antioxidant activities of BCS-II and its subfractions BCS-II-1-4 were compared. Our results showed that the H₂O₂-Vc system did not disrupt the primary functional group of BCS-II, with no significant change in sulfate content between BCS-II and its degraded fractions; however, uronic acid levels increased in degraded fractions when compared with BCS-II. In vitro, BCS-II-4 displayed the lowest molecular weight and had the strongest antioxidant activity. Therefore, the antioxidant activity of chondroitin sulfate in vitro is robustly associated with its molecular weight, and low-molecular-weight chondroitin sulfate can be used as an antioxidant in the food and pharmaceutical industries and other sectors.

Recovery of high-value and scarce resources from biological wastewater treatment: Sulfated polysaccharides

Recovering materials with high value and increasing market demand from sewage and/or sludge is becoming more attractive than recovering traditional resources such as nutrients and biogas. Sulfated polysaccharides (SPs) are valuable and scarce raw materials that can only be produced from marine algae and a few types of animal tissues. This study evaluated if SPs are present in activated sludge obtained from saline sewage with a high level of sulfates present. The presence of SPs-containing extracellular polymeric substances (EPS) was confirmed and quantified for both sludge from lab-scale reactors and full-scale plants for the first time. SPs in the sludge of a lab-scale reactor operated under alternating aerobic/anoxic conditions with 500 mg/L sulfate in the influent (which is typical of Hong Kong saline sewage) reached 342.8 ± 0.3% mg/gVSS, and sludge taken from a full-scale saline wastewater treatment plant (WWTP) contained 418.1 ± 0.4% mg/gVSS of SPs. Purity of the extracted SPs was comparable to that of commercial industrial-grade products. Key bioactivities of SPs (i.e. fucoidan, carrageenan and heparin), namely anti-angiogenesis, anticoagulant and antioxidant, were confirmed after extraction and purification. Interestingly, operating conditions had a strong influence on the contents and types of SPs synthesized in sludge as well as its bioactivities. Although the detailed synthetic pathways of SPs in activated sludge remain unclear, the current study has made a first attempt to recover a high-value scarce resource from biological wastewater treatment.

Identification of a Novel Oligosaccharide in Maple Syrup as a Potential Alternative Saccharide for Diabetes Mellitus Patients

The incidence of diabetes mellitus (DM) is increasing rapidly and is associated with changes in dietary habits. Although restrictions in the use of sweeteners may prevent the development of DM, this might reduce the quality of life of patients with DM. Therefore, there has been a great deal of research into alternative sweeteners. In the search for such sweeteners, we analyzed the carbohydrate content of maple syrup and identified a novel oligosaccharide composed of fructose and glucose, linked at the C-4 of glucose and the C-6 of fructose. This oligosaccharide inhibited the release of fructose from sucrose by invertase (IC₅₀: 1.17 mmol/L) and the decomposition of maltose by α-(1-4) glucosidase (IC₅₀: 1.72 mmol/L). In addition, when orally administered together with sucrose to rats with DM, the subsequent plasma glucose concentrations were significantly lower than if the rats had been administered sucrose alone, without having any effect on the insulin concentration. These findings suggest that this novel oligosaccharide might represent a useful alternative sweetener for inclusion in the diet of patients with DM and may also have therapeutic benefits.

Commercial Saccharomyces cerevisiae Yeast Strains Significantly Impact Shiraz Tannin and Polysaccharide Composition with Implications for Wine Colour and Astringency

To gain knowledge on the role of Saccharomyces cerevisiae yeast strains (and their hybrids) on wine sensory properties, 10 commercially available yeast strains were selected on the basis of their widespread usage and/or novel properties and used to produce Shiraz wines. Significant differences were evident post-alcoholic fermentation and after 24 months of ageing with regards to the number of wine compositional variables, in particular the concentration of tannin and polysaccharide. Strain L2323 is known for its pectinolytic activity and yielded the highest concentration of both yeast- and grape-derived polysaccharides. Wines made with the mannoprotein-producing strain Uvaferm HPS (high levels of polysaccharides) did not have elevated concentrations of yeast-derived polysaccharides, despite this observation being made for corresponding model fermentations, suggesting that mannoprotein production or retention might be limited by the wine matrix. Wine tannin concentration showed a high level of variability between strains, with L2323 having the highest, and AWRI1503 the lowest concentration. Sensory analysis of the wines after 24 months ageing revealed significant differences between the yeast strains, but only the attributes opacity (visual colour) and astringency could be predicted by partial least squares regression using the wine compositional data. Notably, the astringency attribute was associated with higher concentrations of both tannin and polysaccharide, contrary to reports in the literature which suggested that polysaccharide exerts a moderating effect on astringency. The results confirm previous reports demonstrating that the choice of yeast strain represents an opportunity to shape wine style outcomes.

Characterization of Cell Glycocalyx with Mass Spectrometry Methods

The cell membrane plays an important role in protecting the cell from its extracellular environment. As such, extensive work has been devoted to studying its structure and function. Crucial intercellular processes, such as signal transduction and immune protection, are mediated by cell surface glycosylation, which is comprised of large biomolecules, including glycoproteins and glycosphingolipids. Because perturbations in glycosylation could result in dysfunction of cells and are related to diseases, the analysis of surface glycosylation is critical for understanding pathogenic mechanisms and can further lead to biomarker discovery. Different mass spectrometry-based techniques have been developed for glycan analysis, ranging from highly specific, targeted approaches to more comprehensive profiling studies. In this review, we summarized the work conducted for extensive analysis of cell membrane glycosylation, particularly those employing liquid chromatography with mass spectrometry (LC-MS) in combination with various sample preparation techniques.

Structural characteristics of a red ginseng acidic polysaccharide rhamnogalacturonan I with immunostimulating activity from red ginseng

Background

Many researchers reported that the various immune activities of red ginseng are due to acid polysaccharides. But, the exact structural characteristics of the acidic polysaccharide in red ginseng have not been fully elucidated. Therefore, we isolated the acidic polysaccharide from red ginseng and characterized the structural property of the active moiety of this polysaccharide, which contributes to the immunostimulatory activity of red ginseng.

Methods

A polysaccharide (RGP-AP-I) was purified from red ginseng via size-exclusion chromatography using Sephadex G-100. Immunostimulatary activity of RGP-AP-I was investigated via anti-complementory and macrophage stimulatory activity. The structure of RGP-AP-I was characterized by HPLC, sugar composition, β-glucosyl Yariv reagent and methylation analysis.

Results

Peritoneal macrophages stimulated using RGP-AP-I significantly augmented the production of various cytokines such as interleukin (IL)-6, IL-12, and tumor necrosis factor (TNF)-α. The primary structure of RGP-AP-I was elucidated by assessing its sugar composition and methylation analysis. RGP-AP-I is a 96 kDa acidic polysaccharide, and comprises nine different monosaccharides, which mainly include sugars such as rhamnose (Rha, 9.5%), galacturonic acid (GalA, 18.4%), galactose (Gal, 30.4%), and arabinose (Ara, 35.0%). RGP-AP-I exhibited an considerable reaction with the β-glucosyl Yariv reagent, revealing the presence of arabino-β-3,6-galactan. Methylation analysis indicated that RGP-AP-I comprises 21 different glycosyl linkages, such as 3-, 4-, 6- and 3,6-linked Galp; 5-linked Araf; 2,4-linked Rhap; and 4-linked GalAp, which are characteristics of rhamnogalacturonan I (RG-I).

Conclusion

we assumed that the immunostimulatory activity of RGP-AP-I may be due to the RG-I structure, which comprises a main chain with a repeating linkage unit, [→2)-Rhap-(1→4)-GalAp-(1→] and three groups of side chains such as (1→5)-linked arabinan, (1→4)-linked galactan, and arabino-β-3,6-galactan, which branch at the C(O)4 positions of Rha residues in the main chain of RGP-AP-I.

Hindbrain Estrogen Receptor Regulation of Ventromedial Hypothalamic Glycogen Metabolism and Glucoregulatory Transmitter Expression in the Hypoglycemic Female Rat

Neural substrates for estrogen regulation of glucose homeostasis remain unclear. Female rat dorsal vagal complex (DVC) A2 noradrenergic neurons are estrogen- and metabolic-sensitive. The ventromedial hypothalamic nucleus (VMN) is a key component of the brain network that governs counter-regulatory responses to insulin-induced hypoglycemia (IIH). Here, the selective estrogen receptor-alpha (ERα) or -beta (ERβ) antagonists MPP and PHTPP were administered separately to the caudal fourth ventricle to address the premise that these hindbrain ER variants exert distinctive control of VMN reactivity to IIH in the female sex. Data show that ERα governs hypoglycemic patterns of VMN astrocyte glycogen metabolic enzyme, e.g. glycogen synthase and phosphorylase protein expression, whereas ERβ mediates local glycogen breakdown. DVC ERs also regulate VMN neurotransmitter signaling of energy sufficiency [γ-aminobutyric acid] or deficiency [nitric oxide, steroidogenic factor-1] during IIH. Neither hindbrain ER mediates IIH-associated diminution of VMN norepinephrine (NE) content. Both ERs oppose hypoglycemic hyperglucagonemia, while ERβ contributes to reduced corticosterone output. Outcomes reveal that input from the female hindbrain to the VMN is critical for energy reserve mobilization, metabolic transmitter signaling, and counter-regulatory hormone secretion during hypoglycemia, and that ERs control those cues. Evidence that VMN NE content is not controlled by hindbrain ERα or -β implies that these receptors may regulate VMN function via NE-independent mechanisms, or alternatively, that other neurotransmitter signals to the VMN may control local substrate receptivity to NE.

Hindbrain estrogen receptor regulation of ventromedial hypothalamic glycogen metabolism and glucoregulatory transmitter expression in the hypoglycemic male rat

Estrogen receptor-alpha (ERα) and -beta (ERβ) occur in key elements of the brain gluco-homeostatic network in both sexes, including the hindbrain dorsal vagal complex (DVC), but the influence of distinct receptor populations on this critical function is unclear. The ventromedial hypothalamic nucleus (VMN) maintains glucose balance by integrating nutrient, endocrine, and neurochemical cues, including metabolic sensory information supplied by DVC A2 noradrenergic neurons. Current research utilized the selective ERα and ERβ antagonists MPP and PHTPP to characterize effects of DVC ERs on VMN norepinephrine (NE) activity and metabolic neurotransmitter signaling in insulin-induced hypoglycemic (IIH) male rats. Data show that ERβ inhibits VMN glycogen synthase and stimulates phosphorylase protein expression, while attenuating hypoglycemic augmentation of glycogen content. Furthermore, both ERs attenuate VMN glucose concentrations during IIH. Hypoglycemic up-regulation of nitric oxide (NO) and brain-derived neurotrophic factor (BDNF) signaling was correspondingly driven by ERα or -β, whereas GABA and steroidogenic factor-1 were respectively suppressed independently of ER input or by ERβ. IIH intensified VMN NE accumulation by ERβ-dependent mechanisms, but did not alter NE levels in other gluco-regulatory loci. ERβ amplified the magnitude of insulin-induced decline in blood glucose. Both ERs regulate corticosterone, but not glucagon secretion during IIH and oppose hypoglycemic diminution of circulating free fatty acids. These findings identify distinguishing versus common VMN functions targeted by DVC ERα and -β. Sex differences in hypoglycemic VMN NE accumulation, glycogen metabolism, and transmitter signaling may involve, in part, discrepant regulatory involvement or differential magnitude of impact of these hindbrain ERs.

A rapid, accurate and sensitive method for determination of monosaccharides in different varieties of Osmanthus fragrans Lour by pre-column derivatization with HPLC-MS/MS

A specific HPLC-MS/MS (High-Performance Liquid Chromatography with tandem Mass Spectrometry) method was developed and validated for simultaneous determination of several monosaccharides in three kinds Osmanthus fragrans Lour. After extraction, separation, protein removal, pigment removal and hydrolysis, monosaccharides was finally obtained from Osmanthus fragrans Lour. Positive ion mode detection and Multiple Reaction Monitoring (MRM) mode were used for quantitative analysis by PMP pre-column derivatization and Electrospray Ionization (ESI). Analysis and content determination of 6 monosaccharide components in 3 kinds of Osmanthus fragrans Lour. The HPLC separation was achieved on a Shim-pack VP-ODS6022748 (150 L × 2.0) with gradient elution at a flow rate of 0.2 ml/min in a run time of 40 min, and the mobile phase was acetonitrile-5 mmol/L ammonium acetate. PMP derivatization in HPLC-MS/MS can accurately measure Osmanthus fragrans Lour. mannose (Man), ribose (Rib), rhamnose (Rha), galacturonic acid (Gal UA), glucose (Glu), galactose (Gal), xylose (Xyl), fucose (Fuc). The results showed that HPLC-MS/MS pre-column derivatization method was simple and rapid, with small measurement error, but high sensitivity and good repeatability. The analysis of monosaccharide components in polysaccharide components has important practical significance.

Three exopolysaccharides from the liquid fermentation of Polyporus umbellatus and their bioactivities

The exopolysaccharides were extracted and separated from the broth of the liquid fermentation of P. umbellatus, and the antioxidant activities and other relative bioactivities were investigated, aiming to find clues for a wider use in the future. Three novel exopolysaccharides of PPS1, PPS2 and PPS3 with molecular weight of 3.7×10⁴-6.9×10⁴Da were obtained. Monosaccharide analysis showed that they were mainly composed of mannose, along with galactose and glucose with different molar ratio, and their structural features were also investigated by FT-IR, NMR and SEM. The antioxidant activity assay in vitro showed these exopolysaccharides exhibited a significant scavenging effect on DPPH· and other free radicals in a dose-dependent manner. Significantly, the stimulate nitric oxide production and phagocytic activity implied that the polysaccharides could enhance the immunity of RAW 264.7 macrophages. Other assays revealed that they have obvious cellular aging delaying activity and the DNA damage protecting activity. In conclusion, these three exopolysaccharides might have potential applications in the fields of pharmaceuticals, cosmetics, and food products.

One water-soluble polysaccharide from Ginkgo biloba leaves with antidepressant activities via modulation of the gut microbiome

By performing a pyrosequencing-based analysis of bacterial community, we detected that one Ginkgo biloba polysaccharide reversed depression-associated gut dysbiosis and increased the richness of Lactobacillus species which has been proven to be a path to relieve depression.

A heteropolysaccharide from Saccharina japonica with immunomodulatory effect on RAW 264.7 cells

A heteropolysaccharide (SHP) with a strong immunomodulatory effect on RAW 264.7 cells was prepared from Saccharina japonica. Chemical analysis demonstrated that SHP was primarily composed of mannose, glucuronic acid, glucose, fucose, galactose, xylose and rahmnose with a molar ratio of 1.00:0.85:0.84:0.58:0.30:0.37:0.15. ESI-MS showed that depolymerized SHP produced oligo-glucuronan, oligo-glucuronomannan, sulfated fuco-oligosaccharides and other hetero-oligosaccharides. The in vitro immunomodulatory results showed that SHP could increase NO production and up-regulate the expression of many immune effectors, including iNOS, COX-2 and TNF-α, displaying an apparent immune enhancement activities. Western blot analysis proved that SHP activated the expression levels of many key components involved in NF-κB, MAPK and Akt signaling pathways. Our results together indicated that SHP has the potential to be developed as a novel immunomodulator for activating immune system.

Green and Efficient PEG-Based Ultrasonic-Assisted Extraction of Polysaccharides from Tree Peony Pods and the Evaluation of Their Antioxidant Activity In Vitro

We adopted and developed an ultrasonic-assisted extraction method to obtain polysaccharides from tree peony pods using polyethylene glycol (PEG) as the solvent. The technological parameters have been designed as a single factor to enhance the tree peony pod polysaccharide extraction yield. Specific conditions (ultrasound irradiation power, 250 W; ultrasound irradiation time, 30 min; reaction temperature 50°C; liquid-solid ratio, 25 mL/g; and concentration of PEG, 0.2 g/mL) generated an experimental yield of 14.14%  ± 0.44%. Subsequently, the monosaccharide composition of the tree peony pod polysaccharides was determined by HPLC using a 1-phenyl-3-methyl-5-pyrazolone precolumn derivatization method. The results indicated that tree peony pod polysaccharides contained mannoses, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, arabinose, and fucose with a molar ratio of 1.44 : 2.87 : 0.32 : 18.99 : 3.99 : 10.21 : 0.96 : 1.85 : 0.21. The tree peony pod polysaccharides obtained are mainly galacturonic acid and galactose, which are acidic polysaccharides. Finally, the antioxidant activities (DPPH and FRAP) of the tree peony pod polysaccharides were assessed, and the compounds exhibited moderate antioxidant activities.