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The photoactivated periodate (UV/IO4−) process is used to investigate the degradation of acid orange 10 (AO10) dye. The photodecomposition of periodate ions produces highly reactive radicals (i.e., •OH, IO3•, and IO4•) that accelerate dye degradation. Increasing the initial concentration of periodate to 3 mM enhances the dye removal rate, but over 3 mM periodate, the degradation rate slows down. On the contrary, increasing initial dye concentrations reduces the degradation performance. pH is the most critical factor in AO10 breakdown. Salts slow down the degradation of the dye. However, UV/IO4− is more efficient in distilled water than natural water. Even at low concentrations, surfactants may affect the dye’s decomposition rate. The addition of sucrose reduced the breakdown of AO10. Although tertbutanol is a very effective •OH radical scavenger, it does not affect the dye breakdown even at the highest concentrations. Accordingly, the AO10 degradation is a non-•OH pathway route. According to retrieved data, the photoactivated periodate method eliminated 56.5 and 60.5% of the initial COD after 60 and 120 min of treatment time; therefore, it can be concluded that the UV/IO4− system may treat effluents, especially those containing textile dyes.

The present study investigated the structural characteristics and its protective effect against H2O2-induced injury fibroblast cells of Bletilla striata tuber polysaccharide. The polysaccharides were gently extracted by water and recovered using the method of alcohol precipitation, and after further purification by DEAE-Sepharose Fast Flow gel column, a pure polysaccharide (pBSP) was finally obtained. The structural characterization of pBSP were investigated by using periodate oxidation studies, Smith-degradation, FT-IR spectroscopy, 1D and 2D NMR spectroscopy. The antioxidant effect of pBSP was evaluated by inhibiting the production of reactive oxygen species (ROS) in human fibroblast model cells induced by H2O2. It was firstly reported that pBSP was composed of d -glucose and D-mannose in a molar ratio of 1.00:1.34 with a molecular weight of 327.6 kDa. The repeating units of pBSP contained (1 → 4)-linked-β-D-Manp, (1 → 4)-linked-α-D-Glcp and (1 → 3)-linked-β-D-Manp, and there was no branched chain. pBSP exhibited no toxic effect on fibroblasts cells and could protect them against H2O2-induced injuries. After pretreatment with pBSP for 24 h, the content of ROS in fibroblasts decreased significantly. These results not only confirm the availability B. striata, but also indicate that pBSP have potential antioxidant capacity. Our observations can provide foundation for further development of pBSP-based cosmetics.

Hyaluronic acid (HA) is a natural polyelectrolyte abundant in mammalian connective tissues, such as cartilage and skin. Both endogenous and exogenous HA produced by fermentation have similar physicochemical, rheological, and biological properties, leading to medical and dermo-cosmetic products. Chemical modifications such as cross-linking or conjugation in target groups of the HA molecule improve its properties and in vivo stability, expanding its applications. Currently, HA-based scaffolds and matrices are of great interest in tissue engineering and regenerative medicine. However, the partial oxidation of the proximal hydroxyl groups in HA to electrophilic aldehydes mediated by periodate is still rarely investigated. The introduced aldehyde groups in the HA backbone allow spontaneous cross-linking with adipic dihydrazide (ADH), thermosensitivity, and noncytotoxicity to the hydrogels, which are advantageous for medical applications. This review provides an overview of the physicochemical properties of HA and its usual chemical modifications to better understand oxi-HA/ADH hydrogels, their functional properties modulated by the oxidation degree and ADH concentration, and the current clinical research. Finally, it discusses the development of biomaterials based on oxi-HA/ADH as a novel approach in tissue engineering and regenerative medicine.

The antibacterial and biocompatible films have attracted much attention due to their wide range of applications. Although a lot of work has been done in this area, research in this field is still very active and associated with the continuous development of new materials. In the present study full polysaccharide chitosan-agarose (CS-AG) films were produced by reaction of chitosan with periodate activated agarose, followed by reductive amination. Activated agarose was prepared by periodate oxidation of agarose, and then applied as a crosslinking agent to form a new polymeric network. The structure of periodate activated agarose was studied by nuclear magnetic resonances spectroscopy (1H NMR) and Fourier-transform infrared spectroscopy (FT-IR). Rheological experiments showed that the viscosity of agarose solution changes rapidly by addition of periodate to the solution. Swelling, deswelling, and gel content of the films were determined at different pH. Chitosan-agarose silver nanocomposite (CS-AG/n-Ag) films were prepared by loading silver ions and subsequent reduction. The CS-AG/n-Ag films were characterized by FT-IR, thermogravimetric analysis (TGA), and scanning electron microscopy (SEM).Transmission electron microscopy (TEM) image showed that the size of silver nanoparticles was about 2–7 nm. The bactericidal capacities (MBC/MIC) of the CS-AG/Ag films for Pseudomonas aeruginosa (P. aeruginosa), Escherichia coli (E. coli), and Staphylococcus aureus (S. aureus) were obtained 2.0, 1.0 and 2.0, respectively. The results demonstrate that the CS-AG/n-Ag films have good antibacterial activity against both the gram-negative and the gram-positive bacteria which make them suitable for food packaging and wound healing applications.

O-Acetylation is a common naturally occurring modification of carbohydrates and is especially widespread in sialic acids, a family of nine-carbon acidic monosaccharides. O-Acetyl migration within the exocyclic glycerol-like side chain of mono-O-acetylated sialic acid reported previously was from the C7- to C9-hydroxyl group with or without an 8-O-acetyl intermediate, which resulted in an equilibrium that favors the formation of the 9-O-acetyl sialic acid. Herein, we provide direct experimental evidence demonstrating that O-acetyl migration is bidirectional, and the rate of equilibration is influenced predominantly by the pH of the sample. While the O-acetyl group on sialic acids and sialoglycans is stable under mildly acidic conditions (pH < 5, the rate of O-acetyl migration is extremely low), reversible O-acetyl migration is observed readily at neutral pH and becomes more significant when the pH increases to slightly basic. Sialoglycan microarray studies showed that esterase-inactivated porcine torovirus hemagglutinin-esterase bound strongly to sialoglycans containing a more stable 9-N-acetylated sialic acid analog, but these compounds were less resistant to periodate oxidation treatment compared to their 9-O-acetyl counterparts. Together with prior studies, the results support the possible influence of sialic acid O-acetylation and O-acetyl migration to host-microbe interactions and potential application of the more stable synthetic N-acetyl mimics.

Following ultrasonication combined with a hot water extraction, a new type of bioactive polysaccharide, SPS-3-1, was purified from Spirulina using ultrafiltration centrifugation and gel filtration chromatography. The structure of SPS-3-1 was determined with high performance gel permeation chromatography, gas chromatography, periodate oxidation, fourier transform infrared spectroscopy, nuclear magnetic resonance, and atomic force microscopy performance. SPS-3-1 is a homogeneous β-pyran polysaccharide with 1 → 2, 1 → 3, and 1 → 4 glycosyl bonds, mainly composed of d -ribose, l -rhamnose, l -arabinose, l -foucose, and d -glucose. The molar ratio of these components is 1:0.70:1.03:2.1:6.59. The molecular weight of SPS-3-1 is 623.02 kDa. SPS-3-1 has a linear filament structure with a width of 34.132 nm and a height of 819.169 pm. We found that SPS-3-1 significantly enhanced transepithelial electrical resistance, a tight junction integrity marker, in a Caco-2 intestinal cell monolayer model. Analysis of the effect of SPS-3-1 on cell proliferation showed that SPS-3-1 inhibited the in vitro growth of Caco-2 and HepG2 cells with an IC50 of 566.67 μg/mL and 1078.95 μg/mL, respectively.

In this work, we prepared novel cellulosic paper by incorporating tannin into the kraft pulp for potential application in active food packaging. The kraft pulp fibers were firstly periodate oxidized to obtain the dialdehyde cellulosic fibers, and then reacted with varied dosages of tannin to incorporate them into the fibers by covalent bondings between aldehyde groups on cellulose and active hydrogen on tannin. Handsheets were prepared using the tannin incorporated fibers through papermaking process and the properties were characterized. The percentage of tannin in the paper increased with the increase of the tannin dosage. FT-IR spectra confirmed the successful incorporation of tannin into the cellulosic fibers. It was found that paper after incorporation of tannin turned to be surface hydrophobic with contact angles higher than 90°, which may probably due to the covalent bonds between tannin and cellulose. The handsheets show high antioxidative and UV-shielding properties, which both increased with the increase of the tannin percentage in the paper. Water vapor transmission rate (WVTR) decreased after the incorporation of tannin, and this could facilitate its application in food packaging. The breaking length of tannin incorporated paper decreased insignificantly, less than 10% with the tannin percentage as high as 45%.

Rhizosheaths function in plant‐soil interactions and are proposed to form due to a mix of soil particle entanglement in root hairs and the action of adhesive root exudates. The soil‐binding factors released into rhizospheres to form rhizosheaths have not been characterised. Analysis of the high molecular weight root exudates of both wheat and maize plants indicate the presence of complex, highly branched polysaccharide components with a wide range of galactosyl, glucosyl and mannosyl linkages that do not directly reflect cereal root cell wall polysaccharide structures. Periodate oxidation indicates that it is the carbohydrate components of the high molecular weight exudates that have soil‐binding properties. The root exudates contain xyloglucan (LM25), heteroxylan (LM11/LM27) and arabinogalactan‐protein epitopes (LM2) epitopes and sandwich‐ELISA evidence indicates that, in wheat particularly, these can be interlinked in multi‐polysaccharide complexes. Using wheat as a model, exudate‐binding monoclonal antibodies have enabled the tracking of polysaccharide release along root axes of young seedlings and their presence at root hair surfaces and in rhizosheaths. The observations indicate that specific root exudate polysaccharides, distinct from cell wall polysaccharides, are adhesive factors secreted by root axes and that they contribute to the formation and stabilization of cereal rhizosheaths.

The applications of dextran depend not only on the molecular weight but also on the types and number of branches. In this study, dextran generated from Leuconostoc mesenteroides (L.M.CICC-20724) was characterized by fourier-transform infrared spectrum and nuclear magnetic resonance spectroscopy. Our analyses showed that dextran was a polysaccharide composed of d -glucose units with predominantly α(1 → 6) linkages in the main chain and few α(1 → 3) linkages in the branch. Periodate oxidation, a classic chemical method, was usually combined with Smith degradation and gas chromatography to analyze glycosidic linkages in polysaccharide quantitatively. In this study, we calculated the exact straight-chain/branched-chain ratio in the dextran using periodate oxidation only. The ratios obtained by periodate oxidation only were compared to the ratios obtained by nuclear magnetic resonance. The results showed that the ratios of the two groups were nearly equal, and the average relative error between the two groups was 0.83%. This method was evaluated and found to be accurate and stable. This technique provided a convenient and straightforward chemical method for the quantitative analysis of the straight-chains and branched-chains in polysaccharides which had a similar structure. The ratios during the enzymatic synthesis process of dextran were analyzed by this method and were found to be stable with a high level of approximately 95% on average.

In this study, Dendrobium officinale polysaccharide (named DOPS-1) was isolated from the stems of Dendrobium officinale by hot-water extraction and purified by using Sephadex G-150 column chromatography. The structural characterization, antioxidant and cytotoxic activity were carried out. Based on the results of HPLC, GC, Congo red experiment, together with periodate oxidation, Smith degradation, SEM, FT-IR, and NMR spectral analysis, it expressed that DOPS-1 was largely composed of mannose, glucose and galacturonic acid in a molar ratio of 3.2 : 1.3 : 1. The molecular weight of DOPS-1 was 1530 kDa and the main chain was composed of (1→4)-β-D-Glcp, (1→4)-β-D-Manp and 2-O-acetyl-(1→4)-β-D-Manp. The measurement results of antioxidant activity showed that DOPS-1 had the strong scavenging activities on hydroxyl radicals, DPPH radicals and superoxide radicals and the high reducing ability in vitro. Moreover, DOPS-1 was cytotoxic to all three human cancer cells of MDA-MB-231, A549 and HepG2.

In the preparation of commercial conjugate vaccines, capsular polysaccharides (CPS) must undergo chemical modification to generate the reactive groups necessary for covalent attachment to a protein carrier. One of the most common approaches employed for this derivatization is sodium periodate (NaIO4) oxidation of vicinal diols found within CPS structures. This procedure is largely random and structurally damaging, potentially resulting in significant changes in the CPS structure and therefore its antigenicity. Additionally, periodate activation of CPS often gives rise to heterogeneous conjugate vaccine products with variable efficacy. Here, we explore the use of an alternative agent, galactose oxidase (GOase) isolated from Fusarium sp. in a chemoenzymatic approach to generate a conjugate vaccine against Streptococcus pneumoniae. Using a colorimetric assay and NMR spectroscopy, we found that GOase generated aldehyde motifs on the CPS of S. pneumoniae serotype 14 (Pn14p) in a site-specific and reversible fashion. Direct comparison of Pn14p derivatized by either GOase or NaIO4 illustrates the functionally deleterious role chemical oxidation can have on CPS structures. Immunization with the conjugate synthesized using GOase provided a markedly improved humoral response over the traditional periodate-oxidized group. Further, functional protection was validated in vitro by measure of opsonophagocytic killing and in vivo through a lethality challenge in mice. Overall, this work introduces a strategy for glycoconjugate development that overcomes limitations previously known to play a role in the current approach of vaccine design.

Glycosylation is one of the most important post-translational modifications (PTMs) with essential physiological functions, including protein folding, cell signaling and immune response. Thus, various qualitative and quantitative glycomics analysis strategies have been developed. Recently, isobaric multiplex reagents for carbonyl containing compound (SUGAR) tag was developed for quantitative glycomics with multiplexing capacity and increased reporter ion yield. To further improve quantification efficiency and enable quantifying low abundance species, mass defect based triplex SUGAR (mdSUGAR) tag has been designed. In addition, we also introduce additional reaction sites for mdSUGAR at terminal sialic acid by periodate oxidation of polyhydroxy chain to extend the mass difference and lower the requirement for resolving power. As a result, mdSUGAR tags show complete labeling efficiency, improved fragmentation pattern and accurate quantification. Moreover, the quantitative performance of the mdSUGAR tags in complex system has been systematically evaluated and demonstrated reliable results.

Platinum (Pt) and palladium (Pd) have widespread applications, such as in catalysts, jewelry, fuel cells, and electronics because of their favorable physical and chemical properties. Recovery of Pt and Pd from secondary sources is of great concern due to the increased market demand and limitation of the natural reserves of these precious metals. The aim of this research is to achieve recovery of Pt and Pd ions from dilute aqueous solution using dialdehyde of carboxymethyl cellulose (DCMC) crosslinked chitosan (Ch-DCMC). The DCMC was prepared by periodate oxidation of carboxymethyl cellulose (CMC). Both the DCMC and Ch-DCMC were characterized before and after Pt or Pd adsorption using Fourier-transformed infrared (FTIR) spectroscopy, X-ray powder diffraction (XRPD), and scanning electron microscopy (SEM). The effect of cross-linking ratios of chitosan and DCMC (1:1, 1:0.8, 1:0.5, 1:0.25 and 1:0.1) on the Pt and Pd recovery was studied. The optimal cross-linking ratio was found to be 1:0.25 (chitosan: DCMC) with maximum adsorption capacity of 80.8 mg/g Pt and 89.4 mg/g Pd. High selectivity for Pt and Pd compared to base metals and common anions was achieved.

A previously unknown, water-soluble polysaccharide, named DOTP-B, was isolated from the roots of the plant Dioscorea opposita Thunb, a well-known edible and medicinal plant in China. DOTP-B was found to be neutral in charge, with an average molecular weight of 5623 Da. Monosaccharide composition analysis by GC–MS revealed that DOTP-B was a hetero-polysaccharide consisting of glucose and galactose at a molar ratio of 14.6:1.0. Structural features of DOTP-B were investigated with a combination of chemical and instrumental methods, including complete acid hydrolysis, periodate oxidation, methylation, GC–MS, FTIR and several NMR spectra. Highly correlated results demonstrated that the main chain of DOTP-B consisted of →4)-α- d -glc(1 → residues, with about 6% internal →6)-β- d -gal(1 → residues. The antioxidant activity of DOTP-B was also evaluated as the EC50 values against DPPH and PTIO radicals were 2.1 ± 0.1 mg/mL and 1.6 ± 0.1 mg/mL, respectively. Therefore, the polysaccharide DOTP-B could be possibly developed as a promising natural antioxidant for application in medical and food industries.

Heparin is a polypharmacological agent with anticoagulant activity. Periodate oxidation of the nonsulfated glucuronic acid residue results in non-anticoagulant heparin derivative (NACH) of reduced molecular weight. Similar treatment of a low molecular weight heparin, dalteparin, also removes its anticoagulant activity, affording a second heparin derivative (D-NACH). A full structural characterization of these two derivatives reveals their structural differences. SPR studies display their ability to bind to several important heparin-binding proteins, suggesting potential new therapeutic applications.

Kinetics of PEG-200 oxidation by potassium periodatewas studied in alkaline medium. First-order dependence of reaction on periodate was observed. Rate of the reaction was found to be independent of substrate concentration. An inverse fractional order with respect to alkaliwas shown. Arrhenius parameters were calculated. Rate law was postulated taking into consideration of experimental results.

Raw wood was subjected to sequential oxidation to produce 2,3,6-tricarboxycellulose (TCC) nanofibers with a high surficial charge of 1.14 mmol/g in the form of carboxylate groups. Three oxidation steps, including nitro-oxidation, periodate, and sodium chlorite oxidation, were successfully applied to generate TCC nanofibers from raw wood. The morphology of extracted TCC nanofibers measured using TEM and AFM indicated the average length, width, and thickness were in the range of 750 ± 110, 4.5 ± 1.8, and 1.23 nm, respectively. Due to high negative surficial charges on TCC, it was studied for its absorption capabilities against Pb2+ ions. The remediation results indicated that a low concentration of TCC nanofibers (0.02 wt%) was able to remove a wide range of Pb2+ ion impurities from 5–250 ppm with an efficiency between 709–99%, whereby the maximum adsorption capacity (Qm) was 1569 mg/g with R2 0.69531 calculated from Langmuir fitting. It was observed that the high adsorption capacity of TCC nanofibers was due to the collective effect of adsorption and precipitation confirmed by the FTIR and SEM/EDS analysis. The high carboxylate content and fiber morphology of TCC has enabled it as an excellent substrate to remove Pb2+ ions impurities.

High amounts of toxic textile dyes are released into the environment due to coloring and wastewaters treatment processes' inefficiency. To remove dyes from the environment and wastewaters, researchers focused on applying immobilized enzymes due to mild reaction conditions and enzyme nontoxicity. Laccases are oxidases with wide substrate specificity, capable of degradation of many different dye types. Laccase from Streptomyces cyaneus was expressed on the surface of Saccharomyces cerevisiae EBY100 cells. The specific activity of surface-displayed laccase was increased by toluene-induced lysis to 3.1 U/g of cell walls. For cell wall laccase immobilization within hydrogel beads, alginate was modified by dopamine using periodate oxidation and reductive amination and characterized by UV–Vis, FTIR, and NMR spectroscopy. Cell wall laccase was immobilized within alginate and dopamine-alginate beads additionally cross-linked by oxygen and laccase. The immobilized enzyme's specific activity was two times higher using dopamine-alginate compared to native alginate beads, and immobilization yield increased 16 times. Cell wall laccase immobilized within dopamine-alginate beads decolorized Amido Black 10B, Reactive Black 5, Evans Blue, and Remazol Brilliant Blue with 100% efficiency and after ten rounds of multiple-use retained decolorization efficiency of 90% with Evans Blue and 61% with Amido Black. This is the peer-reviewed version of the article: Popović, N.; Pržulj, D.; Mladenović, M.; Prodanović, O.; Ece, S.; Ilić Đurđić, K.; Ostafe, R.; Fischer, R.; Prodanović, R. Immobilization of Yeast Cell Walls with Surface Displayed Laccase from Streptomyces Cyaneus within Dopamine-Alginate Beads for Dye Decolorization. International Journal of Biological Macromolecules 2021, 181, 1072–1080. [https://doi.org/10.1016/j.ijbiomac.2021.04.115]. Supplementary material: [https://cherry.chem.bg.ac.rs/handle/123456789/4405]

We previously reported the precise structure of acidic free-glycans in human urine. In the present study, structural analysis of neutral free-glycans in urine was performed in fine detail. Urine samples were collected from 21 healthy volunteers and free-glycans extracted from the creatinine-adjusted urine and then fluorescently labeled with 2-aminopyridine. Neutral glycan profiling was achieved by a combination of high-performance liquid chromatography, mass spectrometry, enzymatic digestion, and periodate cleavage. A total of 79 glycans were identified. Because the ABO-blood group antigen containing urinary neutral glycans are major components, profiling patterns were similar between individuals of the same ABO-group. The neutral glycans were composed of lactose-core (Galβ1-4Glc) glycans, type-II N-acetyllactosamine-core (GlcNAcβ1-4Glc) glycans, hexose oligomers, N-glycans and to our surprise β1-3 galactosylglucose-core (Galβ1-3Glc) glycans. Although glycans with a β1-3 galactosylglucose-core were identified as major components in urine, comprising structurally simple isomers of a lactose-core, the core structure has not previously been reported. The major β1-3 galactosylglucose-core glycans were Fucα1-2Galβ1-3(Fucα1-4)Glc, GalNAcα1-3(Fucα1-2)Galβ1-3(Fucα1-4)Glc and Galα1-3(Fucα1-2)Galβ1-3(Fucα1-4)Glc, corresponding to H-, A-, and B-blood group antigens, respectively. Three lactosamine extended β1-3 galactosylglucose-core glycans were also detected as minor components. Elucidating the biosynthesis of β1-3 galactosylglucose will be crucial for understanding the in vivo function of these glycans.

Introduction Development of a tissue-engineered construct for hepatic regeneration remains a challenging task due to the lack of an optimum environment that support the growth of hepatocytes. Hydrogel systems possess many similarities with tissues and have the potential to provide the microenvironment essential for the cells to grow, proliferate, and remain functionally active. Methods In this work, fibrin (FIB) incorporated injectable alginate dialdehyde (ADA) - gelatin (G) hydrogel was explored as a matrix for liver tissue engineering. ADA was prepared by periodate oxidation of sodium alginate. An injectable formulation of ADA-G-FIB hydrogel was prepared and characterized by FTIR spectroscopy, Scanning Electron Microscopy, and Micro-Computed Tomography. HepG2 cells were cultured on the hydrogel system; cellular growth and functions were analyzed using various functional markers. Results FTIR spectra of ADA-G-FIB depicted the formation of Schiff's base at 1608.53 cm−1 with a gelation time of 3 min. ADA-G-FIB depicted a 3D surface topography with a pore size in the range of 100–200 μm. The non-cytotoxic nature of the scaffold was demonstrated using L929 cells and more than 80 % cell viability was observed. Functional analysis of cultured HepG2 cells demonstrated ICG uptake, albumin synthesis, CYP-P450 expression, and ammonia clearance. Conclusion ADA-G-FIB hydrogel can be used as an effective 3D scaffold system for liver tissue engineering.

Streptococcal protein G, type III bacterial Fc receptor, is a globular protein produced by Streptococcal species and is composed of three nearly identical domains, each of 55 amino acids. SpG binds the Fc regions of antibodies IgG from many mammalian species [1-4]. The amino acid sequence of the IgG-binding regions (C1, C2 and C3) of SpG are not homologous to those of the regions (E, D, A, B and C) of SpA. A prerequisite of SpG for successful binding affinity to many IgG is the possession of at least two domains [3]. Streptococcal protein G has been shown to have high binding affinity to sera from various mammalian species including human, , cow, pig, rabbit, goat and sheep by using competitive RIA [5] and to cervids, giraffes and peccaries by direct ELISA [2]. More recently using direct ELISA, some new interactions of SpG with free-ranging nondomestic hoofstock (order Artiodactyla) such as addax, bontebok, antelope, bison, elk, impala, kudu/nyala, oryx, muntjac, sheep, and white-tailed deer have been reported [1,2]. SpG does not bind to the Fc region of the immunoglobulin Y (IgY) of avian species [6]. This reagent can be used in ELISA, Western blotting oand Dot blot to detect antigens and antibodies [1]. It is important in the immunodiagnosis of infectious diseases and other problems. Protein L binds to kappa light chains of immunoglobulins from many animal species including human, mouse, rat, chicken, hamster and pig [1]. 1. Justiz-Vaillant AA, Akpaka PE, McFarlane-Anderson N, Smikle MF. Comparison of techniques of detecting immunoglobulin-binding protein reactivity to immunoglobulin produced by different avian and mammalian species.West Indian Med J. 2013;62(1):12-20. 2. Stöbel K, Schönberg A, Staak C. A new non-species dependent ELISA for detection of antibodies to Borrelia burgdorferi s. l. in zoo animals.Int J Med Microbiol. 2002;291 Suppl 33:88-99. doi:10.1016/s1438-4221(02)80018-2. 3. Kronvall G. A surface component in group A, C, and G streptococci with non-immune reactivity for immunoglobulin G. J Immunol 1973, 111(5): 1401-6. 4. Justiz-Vaillant AA, McFarlane-Andersonv N, Wisdom B, Mohammed W, Vuma S, et al. Immunoglobulin-binding Bacterial Proteins (IBP) Conjugates and their Reactivity with Immunoglobulin in Enzyme-Linked Immunosorbent Assays (ELISA). J Anal Bioanal Tech 2013, 4: 175. 5. Reis KJ, Ayoub EM, Boyle MD. Streptococcal Fc receptors. II. Comparison of the reactivity of a receptor from a group C streptococcus with staphylococcal protein A. J Immunol 1984, 132(6): 3098-102. 6. Serhir B, Dubreuil D, Higgins R, Jacques M. Purification and characterization of a 52-kilodalton immunoglobulin G-binding protein from Streptococcus suis capsular type 2. J Bacteriol 1995, 177(13): 3830-6.

In this study, the Zodo gum exudated by Amygdalus scoparia spach underwent the periodate oxidation process for chemical modification and the formation of dialdehyde groups. Modification of the Zodo gum properties was done using the periodate oxidation method, response surface methodology (RSM) and central composite design (CCD), with 4 factors of sodium periodate volume (6.4–19.2 mL), temperature (35–55 °C), pH (3–5) and time (2–4 h). Dialdehyde Zodo gum (DZG) was produced by controlling test variables and measuring some responses including dialdehyde content and efficacy, in addition to evaluating the rheological parameters. Quadratic, linear polynomial equations were then fitted with the insignificant Lack of fit and high R2 to address the relationship between the mentioned variables and responses. Optimal test conditions, including pH = 3.9, T = 43 °C and Time = 3.5 h, were also determined for the production of DZG10, DZG20 and DZG30 samples. The results of 1H-13C NMR, FTIR and determination of the aldehyde content indicated the formation of dialdehyde groups in equilibrium with the dominant hemiacetal form. The AFM study of the DZG30 sample also showed over-oxidation and depolymerization, which could be associated with increased hydrophobic properties and the reduced viscosity. Although the DZG30 sample had the highest amount of the dialdehyde factor group with the tendency to combine with the amino group of proteins, DZG10 and DZG20 samples could be recommended for industrial applications due to the nonoccurrence of overoxidation.

Galactomannan extracted from Cassia fistula seed endosperm present little data related to the its structural characterization. This study reports the chemical characterization of the galactomannan from Cassia fistula (CF) and their oxidized derivatives. The extracted CF presented a yield of 26.5% (w/w) and the intrinsic viscosity [η] was 9.73 dL/g. 1D and 2D nuclear magnetic resonance spectroscopy (NMR) confirmed that the polysaccharide has a backbone of 4-linked β-D-mannose units, and contains galactose units as pending groups. These galactose units are linked to the central core through a (1→6) linkage and the galactomannan presented Man/Gal ratio of 3.1/1. The galactomannan from Cassia fistula presents low cytotoxicity in Vero cells with a CC50 > 1000 μg/ml. The properties of CF resemble other commercially important galactomannans such as Locust bean gum. Three oxidized derivatives of CF were produced by periodate oxidation, which were carefully characterized by different structural techniques. It was observed that as the degree of oxidation increased, there was an increase in the Man/Gal ratio and a reduction in molar mass and viscosity. The polialdehyde produced may be explored as a versality material to react with amine group of the protein and amined polysaccharide to produce biomaterials.

In the study, the β-glucan content, the primary structure and the antioxidant capacity of polysaccharides in Cordyceps militaris cultivated with different initial growth pH were evaluated. Meanwhile, the mechanism of β-glucan biosynthesis was investigated by RNA-Seq. Based on the results, C. militaris growing at an initial growth pH of 5–7 (CMsA) was distinguished from C. militaris growing at an initial growth pH of 8–9 (CMsB) and their unigenes showed the comparable expression. The mean of β-glucan content of CMsB group was 32.7% (w/w), 10% higher than that of CMsA. The results of RNA-seq showed 1088 differentially expressed genes between CMsA and CMsB groups. Furthermore, oxidative phosphorylation-related Gene ontology terms were up-regulated in CMsB groups. In addition, the results of structural analysis (FTIR spectrum, monosaccharide composition, periodate oxidation) and bioactivity evaluation speculated that C. militaris polysaccharides possessed higher β-(1 → 6)-glucan content and antioxidant activities in CMsB groups.

A new core-shell structured nanomaterial based on Fe3O4 nanoparticles and 2,3-dialdehyde nanocrystalline cellulose (DAC) coating and its high efficiency in the preconcentration of glycoproteins were described in this work. DAC was obtained after the periodate oxidation of nanocrystalline cellulose to form aldehyde groups; then, Fe3O4 nanoparticles were coated with DAC, which were further attached to 4-aminophenylboronic acid (PBA) to form PBA-functionalized magnetic core-shell structured materials (Fe3O4@DAC-PBA). The oxidation of cellulose and the production of sufficient amounts of aldehyde group sites were essential for the preparation of Fe3O4@DAC-PBA used for the affinity adsorption of glycoproteins because the aldehyde groups on DAC allowed DAC to attach to the Fe3O4 nanoparticles and bind with PBA, which was active in forming a complex with the glyco sites in glycoproteins. Moreover, the preconcentration properties of Fe3O4@DAC-PBA through PBA adsorption can be pH-triggered without the disassembly of the structures; thus, the developed Fe3O4@DAC-PBA can be efficiently prepared to provide a promising affinity material for the affinity adsorption and purification of glycoproteins.

Many industrial enzymes can be highly glycosylated, including the β-glucosidase enzymes. Although glycosylation plays an important role in many biological processes, such chains can cause problems in the multipoint immobilization techniques of the enzymes, since the glycosylated chains can cover the reactive groups of the protein (e.g., Lys) and do not allow those groups to react with reactive groups of the support (e.g., aldehyde and epoxy groups). Nevertheless, the activated glycosylated chains can be used as excellent crosslinking agents. The glycosylated chains when oxidized with periodate can generate aldehyde groups capable of reacting with the amino groups of the protein itself. Such intramolecular crosslinks may have significant stabilizing effects. In this study, we investigated if the intramolecular crosslinking occurs in the oxidized β-glucosidase and its effect on the stability of the enzyme. For this, the oxidation of glycosidic chains of β-glucosidase was carried out, allowing to demonstrate the formation of aldehyde groups and subsequent interaction with the amine groups and to verify the stability of the different forms of free enzyme (glycosylated and oxidized). Furthermore, we verified the influence of the glycosidic chains on the immobilization of β-glucosidase from Aspergillus niger and on the consequent stabilization. The results suggest that intramolecular crosslinking occurred and consequently the oxidized enzyme showed a much greater stabilization than the native enzyme (glycosylated). When the multipoint immobilization was performed in amino-epoxy-agarose supports, the stabilization of the oxidized enzyme increases by a 6-fold factor. The overall stabilization strategy was capable to promote an enzyme stabilization of 120-fold regarding to the soluble unmodified enzyme., The authors thank the support from Research Institute of Food Science (CIAL), Embrapa Instrumentation of São Carlos, Foundation for Research Support of Espírito Santo (FAPES), and Federal University of Espírito Santo (UFES).

EPPS, a new heteropolysaccharide from Echinops pungens roots, was extracted by warm water (70 °C) and fortuitously purified using column chromatographies on DEAE-cellulose A52 and Sephadex G-100. Total carbohydrate content, specific optical rotation and molecular mass of EPPS were 98.3%, −88.2 and 65.7 kDa, respectively. GLC analysis revealed that EPPS was a neutral polysaccharide and contained Gal, Glc, Man, Xyl, and Ara at ratios of 0.96: 5.23:1.00:2.06:1.04. Multiple chemical and instrumental analysis methods such as methylation, periodate oxidation and Smith degradation, partial acid hydrolysis, GLC–MS, FT-IR and NMR (1H and 13C) were employed to elucidate the structure of EPPS and their results showed that its backbone consists of →6)-β-D-Glcp-(1 → residues, with branches attached to O-4 (~38%) by →4)-β-L-Arap-(1→, →4)-β-D-Manp-(1→, →4)-β-D-Xylp-(1→, β-D-Xylp-(1 → and α-D-Galp-(1 → residues. DPPH radical scavenging ability of EPPS was lower than ascorbic acid at identical concentrations and its EC50 value was 1.91 mg/ml.

A novel water-soluble polysaccharide, named ICP-1, was isolated and purified by Sephadex G-200 after extracting the crude polysaccharide (ICP) from Imperial Chrysanthemum. The structural characterization of ICP-1 was determined by physical and chemical methods, FT-IR, NMR, SEM, HPGPC, periodate oxidation, Smith degradation, methylation and Congo red test. Then, acid production and proliferation of lactic acid bacteria and the tolerance tests of simulated gastrointestinal fluid were measured to investigate the activity of prebiotic potential. The results showed that ICP-1 was an acidic hetero-polysaccharide with an average molecular weight of 2.98 × 103 kDa and a specific optical rotation of +155°. The glycosyl residues of ICP-1 were composed of (1→), (1→4) and (1→6) glucose, (1→5) arabinose, (1→4) galacturonic acid and (1→3,6) mannose. Besides, ICP-1 can speed up the acid production of lactic acid bacteria and promote the growth and proliferation of lactic acid bacteria effectively.

A purified polysaccharide, designated CALB-4, was acquired from Fructus aurantii that is the traditional edible/medicina plant in China. The present study was performed to characterize the CALB-4 and to evaluate its immunomodulatory activities on human peripheral blood mononuclear cells (PBMCs). The structure of CALB-4 was characterized by partial acid hydrolysis, periodate oxidation, Smith degradation, and methylation analysis combined with gas chromatography-mass spectrometry (GC-MS), Infrared Spectroscopy (IR) and scanning electron microscopy (SEM). The results indicated that CALB-4 was elucidated as a pectic polysaccharide and its main chain is composed of Man, Gal UA and Gal, interspersed with Ara, Rha, Man and Gal. Furthermore, immunological tests showed that CALB-4 exhibits the immunoenhancement effects. The mechanism for this action might be attributed to the increase of the cytoplasmic concentration of pro-IL-1 via the up-regulation of several mitogen-activated protein kinases (MAPKs) and the nuclear translocation of p65. This study clarified that CALB-4 could be as an efficacious biological response modifier in immunotherapy.

The purpose of this study was to estimate the antibacterial properties of aqueous suspensions of dialdehyde microcrystalline cellulose (DAMC), and a model of the observed antibacterial kinetics was proposed and validated. The DAMC was prepared from microcrystalline cellulose by periodate oxidation. The bacterial inactivation kinetics of aqueous suspensions of DAMC was investigated by measuring the bactericidal effect after different contact times. The results indicated that with a DAMC aldehyde content of 6.34 mmol/g, the MICs for S. aureus, E. coli, B. subtilis and S. typhimurium were 15, 15, 15 and 30 mg/mL, respectively. This research thus establishes an antibacterial kinetics model of DAMC with 6.34 mmol/g of aldehyde content. At 37 °C and atmospheric pressure, the bacterial inactivation kinetic conformed to the equation: Log reduction of bacteria = - k [DAMC] t.

We have developed an indirect fluorescence method for the determination of nitrite based on two reactions. The S-nitrosocaptopril produced by the first reaction between nitrite and excess captopril is not fluorescent. The fluorescent product produced by the residual captopril with glycine and o-phthalaldehyde is then measured and related to the nitrite concentration. We have optimized comprehensively the reaction condition parameters, including the thiol regent for the two reactions, reaction temperature and pH value for the first reaction, and the choice of amino acid, pH value, the ratio of reactants, buffer concentration, reaction temperature, and time for the second fluorescence reaction. Potential interferences by 8 cations and 10 anions on the fluorescence intensity were slight except for iodate and periodate which could likely be removed by addition of a reducing agent. For the analytical figures of merit, the limits of detection and quantitation of nitrite are 0.8 and 2.5 nM, respectively....

Objective Immunoassay usually deal with the antibody labeling with various reporter molecules, one such useful reporter molecule is horseradish peroxidase (HRPO). Conjugating enzyme with antibody without losing its enzymatic activity is a challenging task. Our aim is to modify existing classical method of conjugating antibodies with HRP to enhance immunoassay techniques with better sensitivity. We used chemicals such as sodium meta periodate to generate aldehyde group by oxidation of carbohydrate moieties on HRPO. The activated form of HRPO is lyophilized and then mixed with 1 mg/ml concentration of antibodies to be conjugate. Results After confirming chemical modification of conjugates via UV-Spec and SDS-PAGE independent molecules were used for conjugation and HRP–antibody conjugate. Finally, enzymatic activity of HRP–antibody conjugate was confirmed by performing direct ELISA. Functional properties were analyzed using ELISA with dilution of 1:5000, whereas the conjugate prepared by existing method of conjugation worked with as low dilution of 1:25 with a p value highly significant (

A new water-soluble polysaccharide named as AAPS-1, was extracted with warm water from the roots of Acanthophyllum acerosum and further purified by DEAE-cellulose A52 anion-exchange and Sephadex G-50 gel filtration chromatography. AAPS-1 was a neutral polysaccharide, with a molecular weight of 23.2 kDa and a specific optical rotation of +181.3° (c 1.0, H2O), and comprised of Glucose, Galactose and Arabinose with a relative molar ratio of 1.6:5.1:1.0. Structure features of AAPS-1 were investigated by a combination of chemical and instrumental analysis, such as partial acid hydrolysis, methylation, periodate oxidation and Smith degradation, GC–MS, FTIR and NMR (13C and 1H). The data obtained indicate that AAPS-1 possessed a backbone of →6)-α- d -Galp-(1→ residues, with branches attached to O-2 (∼35%) by α- d -Glcp-(1→ and at O-3 (∼16%) by α- d -Galp-(1→ and by β- l -Arap-(1 → 3)-β- l -Arap-(1 → 3)-β- l -Arap-(1→. The scavenging activity of AAPS-1 against DPPH radical was less than that of ascorbic acid at the same concentrations and the EC50 value of AAPS-1 was 1.4 mg/ml.

In this study, 2,3-dialdehyde starch crystal was used as a novel and low-toxicity bio-crosslinker to design composite gelatin-based films with both superior mechanical and barrier properties. The starch crystal containing aldehyde group was fabricated via periodate oxidation as an efficient cross-linker to reinforce the gelatin-based bio-composite films. X-ray photoelectron spectroscopy (XPS) and 1Hydrogen nuclear magnetic resonance (1H-NMR) revealed that di-aldehyde starch crystal (Di-SC) could react and covalently cross-link with the amine group of gelatin molecules via C=N chemical bond. The tensile strength of gelatin film containing 10% di-aldehyde starch crystal (G/Di-SC-10%) exhibited a tensile strength of 70.8 MPa, which was 967% higher than that of neat gelatin film (6.7 MPa). Additionally, the hydrophobic properties, thermal stability and surface morphology of G/Di-SC-10% were significantly enhanced, and so was its UV-barrier shield efficiency. Our results indicate that the new gelatin/di-aldehyde starch crystal bio-composite film has potential practical applications in the edible film-based packaging industry.

The calcium hydroxide extractable polysaccharides isolated from bran, spent grain and sorghum grains were separated on diethylaminoethyl-cellulose column into five sub-fractions each, by eluting successively with different eluents. These fractions differed in their yield, uronic acid contents and composition of neutral sugars as well as phenolic acids. The major fractions (0.1 M ammonium carbonate eluted) were resolved into a single peak each on Sephacryl S-400 and their homogeneity was ascertained by HPSEC. Ferulic acid was the major phenolic acid (19.84–29.32 mg/100 g) bound to arabinoxylan-(AX) type polysaccharides. The molecular weights were found to be 126.6 kDa for bran and spent grain, and 223.9 kDa for sorghum grains AX. The structural characterization of the purified polysaccharides, carried out by 13C NMR, 1H NMR, FTIR, periodate oxidation, Smith degradation and optical rotation analysis, indicated their backbone to be 1,4-β-D-xylan (optical rotation ranged from – 4.0 to – 7.8), substituted mainly at O-2 or O-3 and/or both by α-L-arabinose residues. As evident from the determination of colour characteristics and high thermostability (T0 > 200 °C), these polysaccharides can be used in the preparation of fibre-rich foods including bakery products.

This research article reports the coating of large pore silica microparticles with a maltose layer to which bioaffinity ligands were attached via reductive amination reaction between the aldehyde activated maltose and the amino groups of the bioaffinity ligands. This was achieved first by the periodate oxidation of the maltose-silica (MALT-silica) yielding pairs of aldehyde groups at each monosaccharide ring. These di-aldehyde functionalities were then reacted with the primary amino groups of protein bio-affinity ligands and eventually formed Schiff bases (i.e., aldimines) which were reduced using the mild reducing agent sodium cyanoborohydride to form stable amine linkages between the immobilized protein ligands and the maltose layer. Anti-human serum albumin antibody (aHSA), anti-human serum transferrin antibody (aTf) and concanavalin A (Con A) were the bio-affinity ligands immobilized onto the MALT-silica and were evaluated in high performance affinity chromatography (HPAC), namely immunoaffinity chromatography (IAC) and lectin affinity chromatography (LAC). Our initial studies reported here revealed zero or reduced nonspecific interactions with the two immunoaffinity sorbents (i.e., aHSA-MALT-silica and aTf-MALT-silica) and the lectin affinity sorbent (i.e., Con A-MALT-silica). The absence of nonspecific interactions is attributed to the hydrophilicity of the maltose layer and its shielding effect of the residual silanols (i.e., unreacted silanols) on the silica surface. Conversely, the IAC and LAC sorbents exhibited specific interactions with the target biomolecules, namely human serum albumin (HSA) and transferrin (Tf) in the case of aHSA-MALT-silica and aTf-MALT-silica columns, respectively, and glycoproteins known for their affinity to Con A in the case of Con A-MALT-silica column.

Peroxidase tagged proteins are being used successfully as immune-histological probes for the demonstration of tissue antigens, and in enzyme amplified immunoassay systems for the quantitative determination of soluble and insoluble antigens. The glycoprotein nature of peroxidases can be exploited for conjugation to proteins of interest. Peroxidase extracted from the bulbs of Brassica oleracea gongylodes was salted out at 40-80% ammonium sulfate saturation and activated by treatment with 1-Fluoro-2,4-dinitro benzene (FDNB) and periodate. Treatment with 0.08% FDNB and 12.5mM periodate was optimized for activation of the enzyme. The treated enzyme was found to conjugate successfully to immunoglobulin fractions harvested from egg yolk (IgY), human plasma and goat serum. Enzyme conjugated to IgY fraction showed improvement in its pH stability and temperature stability. The affinity of the enzyme for its substrate phenol did not alter to a significant extent upon activation and conjugation. The conjugates exhibited high affinity towards phenol, bromocresol purple and bromothymol blue in comparison to HRP conjugates prepared using the same protocol. Int. J. Appl. Sci. Biotechnol. Vol 5(1): 59-65

Six soluble dietary fiber (SDF) fractions were prepared via stepwise ethanol precipitation from natural and fermented wheat bran. The chemical composition, molecular weight distribution, and glycosidic linkage and substitution pattern of each SDF fraction were elucidated by sugar analysis, periodate oxidation and Smith degradation, molecular determination, and 1H nuclear magnetic resonance (NMR) analysis. The impacts of SDF fractions on the rheological properties and morphologies of doughs were investigated by farinography, rheometry, and scanning electron microscopy (SEM) to clarify the relationship between the microstructural features of SDF fractions and the macroscopic properties of SDF-containing doughs. The interactions between SDF fractions and wheat glutens in doughs were further studied by confocal laser scanning microscopy (CLSM). The experimental results indicated that the SDF fraction with an intermediate molecular weight but a higher substitution degree and a larger disubstitution ratio was m...

Illuminating the complex reactions of molecules in aqueous solution is one of the most important tasks of experimental studies of reaction dynamics. The oxidant diperiodatocuprate(III) (DPC) was used for the oxidation of acebutolol (ACBT) in aqueous alkaline medium, at an ionic strength of 0.30 mol·dm−3. The stoichiometry was found to be 1:2 ([ACBT]:[DPC]). The order of the reaction with respect to [DPC] was unity when [DPC] << [ACBT], while the orders with respect to [ACBT] and [OH−] were less than unity, whereas it was negative less than unity in [ $$ {\text{IO}}_{ 4}^{ - } $$ ] over the concentration range studied. The final products of oxidation were identified by GC–MS analysis. Based on the experimental observations, a plausible mechanism is proposed. The reaction constants involved in the different steps of the reaction mechanism were calculated. The activation parameters and the thermodynamic quantities were determined and discussed. Active species of diperiodatocuprate(III) was found to be monoperiodatocuprate(III), i.e. [Cu(H2IO6)(H2O)2]. An understanding of the mechanism allows the chemistry to be interpreted, understood and predicted.

This work is a critical preventive study for providing a healthy life and enhancing people's safety at work in which introduces of highly efficient and durable UV-protection and antibacterial textiles. With this aim, ZnO nanoparticles are in situ synthesized on the modified cotton fabric to produce the multifunctional fabrics. Herein, the cotton fabric is oxidized by periodate and then treated by 4-aminobenzoic acid ligand (PABA). The modified cotton fabrics are characterized via X-ray powder diffraction, Fourier-transform infrared spectroscopy-attenuated total reflectance, scanning electron microscope, X-ray photoelectron spectroscopy, and thermogravimetric analysis. Moreover, the anti-bacterial, UV-protection, hydrophilicity, and mechanical properties of samples are investigated. The results show that pre-oxidization cotton fabric provides better active sites for the treatment with PABA. Then, PABA treatment provides significant sites for the growth of the ZnO nanoparticles and maintains cross-linking property between oxidized cellulosic fibers and the ZnO nanoparticles which improves the formation and durability of ZnO nanoparticles. The simultaneous sample treatment with ZnO and PABA had synergistic effects on UV protection, stability, and mechanical properties. Moreover, the ZnO PABA oxidized cotton fabrics show excellent UV-protection and significant antibacterial efficacy after 20 washing cycles and 100 abrasion cycles, which can be used in advanced protective textiles.

Grifola frondosa is a basidiomycete fungus with potential biomedical applications owing to the presence of bioactive polysaccharides. The activities of polysaccharides are influenced by many factors, particularly temperature; however, the optimal temperature and conditions for preparation of polysaccharides from this organism have not yet been determined. Therefore, in this study, cold-water soluble polysaccharides from Grifola frondosa were extracted at 4 °C (GFP-4) and purified. GFP-4-30, GFP-4-60 and GFP-4-90 were obtained from GFP-4 after treatment at 30 °C, 60 °C, or 90 °C, respectively, for 6 h. MTT results showed that GFP-4 had the highest inhibitory effects on the proliferation of SPC-A-1 cells in vitro. High-performance gel permeation chromatography results demonstrated that the molecular weight of GFP-4 was 1.05 × 106 Da and that GFP-4-30, GFP-4-60, and GFP-4-90 showed different levels of degradation and generated small molecule sugars. Fourier transform infrared spectroscopy, gas chromatography, and nuclear magnetic resonance results indicated that GFPs mainly consisted of α-D-Galp, α-D-Manp and α-D-Glcp. Periodate oxidation, Smith degradation, and methylation results showed that the backbones of the molecules consisted of 1,3-linked-Galp. After heat treatment, percentages of (1 → 3,4) α-D-Galp in heat-treated polysaccharides were obviously decreased, indicating their lower branching degree, and resulting in weaker antitumor effects. Overall, our findings demonstrated changes in the structure-activity relationships of GFP-4 after heat treatment and provided a theoretical basis for the application of GFP-4 in the food and drug industries.

Modification of Hyaluronic acid (HA) with Sodium metaperiodate (NaIO4) results in the formation of oxidized HA (OHA). OHA containing multiple aldehyde groups can easily react with the materials having amino functionality via formation of Schiff base linkage, resulting in the formation of OHA based hydrogel scaffolds. These hydrogels have recently attracted considerable attention as scaffolds for tissue engineering (TE) applications. Thus, the aim of the present review is to give an overview on OHA based hydrogels as scaffolds and their potential application in the field of TE along with the method of synthesis and important properties of OHA.

This study focused on the in-vivo sustained release of oxytetracycline (OTC) loaded on di-aldehyde cellulose (DAC). The periodate oxidation method was used for the synthesis of DAC. The prepared DAC-OTC material was characterized by different techniques such as Scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Transmission electron microscopy (TEM) and particle size analyzer. The pharmacokinetic studies were performed on DAC-OTC composite system and commercial tablet (COTA). The results of pharmacokinetic studies demonstrated that DAC-OTC exhibited higher area under the curve (AUC) (482.8 μghmL-1) as compared to COTA (90.72 μghmL-1). DAC-OTC composite system has double compartment pattern with improvement in mean residing time (MRT) and area under moment curve (AUMC0-∞) than the commercial tablet (2.8 and 15.13 folds higher, respectively). Swelling index of DAC-OTC at different pH and pKa of OTC release imply that controlled in-vivo release in DAC-OTC composite system could be due to the simultaneous occurrence of the covalent and hydrogen bond between OTC and di-aldehyde cellulose. These results indicate that di-aldehyde cellulose may improve the in-vivo bioavailability of OTC.

In the study, a new triple-helix polysaccharide with favorable stability was purified from C. cornucopioides. Its structural characterization, stability and solution behavior were investigated by the GC–MS, periodate oxidation-smith degradation, FT-IR, 1D and 2D NMR spectroscopy, methylation analysis, Scanning electron microscope, Congo-red, CD, TGA and DSC analysis. The results showed that Craterellus cornucopioide polysaccharide (CCP) possessed the molecular weight of 1.97 × 103 kDa, is mainly composed of mannose (48.73%), galactose (17.37%), glucose (15.97%) and xylose (17.93%), respectively. It was a heteroglycan with (1 → 3)‑linked‑β‑ d ‑Manp‑(1 → 6)‑linked α‑ d ‑Galp backbone distributed by (1 → 4)‑linked‑α‑ d ‑Xylp‑t‑α‑ d ‑Manp and t‑β‑ d ‑Glup units at O-6. The result of TGA and DSC assay indicated that CCP has a favorable thermal stability. MTT and Scanning electro microscopy (SEM) assay showed that CCP could significantly improve the proliferation activity and induce cells activation of RAW264.7 in a certain range of concentrations and period.

The thiol group in cysteine residues is susceptible to several post-translational modifications (PTMs), including prenylation, nitrosylation, palmitoylation, and the formation of disulfide bonds. Additionally, cysteine residues involved in disulfide bonds are commonly reduced and alkylated prior to mass spectrometric analysis. Several of these cysteine modifications, specifically S-alkyl modifications, are susceptible to gas-phase oxidation via selective ion/ion reactions with periodate anions. Multiply protonated peptides containing modified cysteine residues undergo complex formation upon ion/ion reaction with periodate anions. Activation of the ion/ion complexes results in oxygen transfer from the reagent to the modified sulfur residue to create a sulfoxide functionality. Further activation of the sulfoxide derivative yields abundant losses of the modification with the oxidized sulfur as a sulfenic acid (namely, XSOH) to generate a dehydroalanine residue. This loss immediately indicates the presence of an S-alkyl cysteine residue, and the mass of the loss can be used to easily deduce the type of modification. An additional step of activation can be used to localize the modification to a specific residue within the peptide. Selective cleavage to create c- and z-ions N-terminal to the dehydroalanine residue is often noted. As these types of ions are not typically observed upon collision-induced dissociation (CID), they can be used to immediately indicate where in the peptide the PTM was originally located.

An exopolysaccharide (EPS) was fractionated from fermentation media of a Cordyceps sinensis fungus (Cs-HK1) by ethanol precipitation at 2/5 volume ratio of ethanol/media. Its structural characteristics were elucidated by FT-IR, GC, GC–MS, 1D and 2D NMR combined with periodate oxidation, Smith degradation, partial acid hydrolysis, and methylation analysis. Furthermore, the immunomodulatory activity of EPS was evaluated by the model of cyclophosphamide-induced immunosuppression. The results from monosaccharide composition and partial acid hydrolysis indicated that EPS almost consisted of glucose excluding a trace amount of mannose. GC–MS and NMR analysis further confirmed EPS had a linear backbone of (1→3)-β- d -glucopyranosyl residues with a single (1→6)-β- d -glucopyranosyl side-branching unit for every three β- d -glucopyranosyl residues, showing a comb-like β- d -glucan with short and intensive branches, which was responsible for high viscosity. Moreover, EPS could significantly enhance immune organs and stimulate the release of major cytokines TNF-α and INF-γ, suggesting that EPS exhibited protective effect in immunocompromised mice.

In this work, the polysaccharide carboxymethyl cellulose (CMC) was first activated via periodate oxidation then modified by insertion of photo-active cinnamic acid hydrazide moieties to finally produce the photo-crosslinkable CMC-CM with various extents of functionalizations. The chemical structures of the manufactured polymeric materials were entirely investigated utilizing FTIR, 1 H, 13 C NMR, and UV–vis spectra. Upon irradiation in UV light, the progress and kinetics of the cross-linking were detected using UV–vis spectra. Moreover, the crystallinity changes before and after chemical modification and subsequent UV irradiation were examined by XRD spectra. Also, the obtained hydrogels with various cross-linking densities were freeze dried to visualize the morphological changes using SEM. In addition, the rheological experiments indicated the improvement of the hydrogel mechanical properties by increasing both UV irradiation time and degree of cinnamate functionalization. The obtained hydrogel exhibited good swelling, gelation and biodegradation properties, which indicate a promising potential in different biomedical applications.

Peanut proteins conarachin II, conarachin I and arachin were found to behave as highly selective fluorescence sensors for periodate amongst a set of different anions. The interactions of the proteins with periodate were also confirmed by other spectral methods and enzyme linked immunosorbent assay (ELISA). The results indicate a selective interaction of peanut proteins with periodate amongst chloride, sulphate, iodide, phosphate, nitrate, nitrite, bromide, fluoride, persulphate, acetate, thiosulphate, arsenite, arsenate, sulphite, and iodide. Periodate sensing using different synthesized organic molecules are already reported in the literature. In this article we report the efficiency of peanut proteins as anion sensor which are bioactive and inexpensive too. The protein periodate interactions have also resulted in a simultaneous reduction in allergenicity of the peanut proteins. A change in the secondary structure of the protein was found responsible for this change which was further established with the help of circular dichroism and Raman spectroscopy.

Cordyceps militaris, a typical Chinese traditional medicine, and its polysaccharide in functional food is very promising. The aim of this study was to clarify the structural characterization and biological activity of CP2-c2-s2 from C. militaris (CMP). High-performance gel permeation chromatography (HPGPC) and polyacrylamide gel electrophoresis (PAGE) analysis showed that CP2-c2-s2 was a homogeneous polysaccharide with an average molecular weight of 20 200 Da. The Fourier transform infrared spectroscopy (FTIR) and periodate oxidation analysis revealed that CP2-c2-s2 is a β-pyran polysaccharide, probably with 1→2, 1→4, and 1→6 glycosyl linkages. Micromorphologic observation showed different aggregates and networks from 5 μg mL−1 to 250 μg mL−1. CP2-c2-s2 significantly stimulated the proliferation of T and B lymphocytes, and obviously extended the average lifespan without adverse effects on fecundity, and delayed the age-related decrease in Caenorhabditis elegans. Overall, our results revealed significant immunomodulatory and anti-aging activities of CMP, which may provide useful information for CMP in functional foods.