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In this study, removal of P-Nitrophenol (PNP) as a nitro-aromatic contaminant from the aqueous medium have been investigated using the photochemical oxidation process by UV-activated periodate. The...

Two test-systems for a direct and an indirect enzyme-linked immunosorbent assay (ELISA) of peptide antibiotic bacitracin (BC) were developed and studied. For the both systems, polyclonal antibodies were obtained by immunizing rabbits with a conjugate of BC with keyhole limpet hemocyanine synthesized using reaction between the peptide and the high molecular weight protein in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC). The product of BC linking to thyroglobulin which was activated with EDC and N-hydroxysulfosuccinimide served as conjugated antigen on a solid phase in the indirect ELISA. For the direct ELISA, the antibodies against BC were immunochemically immobilized onto microplate surface, while the liquid phase contained a conjugate of BC with horseradish peroxidase. This conjugate was obtained by successive reactions of antibiotic amino groups coupling to periodate oxidized carbohydrate chains of enzyme and the reducting of formed Shiff’s base with sodium borohydride. Conjugated antigens binding to anti-BC antibodies provided maximum colorimetric signals of 2.0 and 1.2 optical units for the direct and indirect ELISA, respectively, and depended on BC content in the liquid phase. Antibiotic concentration that caused the inhibition of binding by 50 % was 2.6 ng/ml in the direct ELISA and 10.0 ng/ml in the indirect ELISA. The simple and sensitive direct ELISA system was used as a prototype of the finished reagent kit and a method for measurements with technical-analytical parameters and metrological characteristics allowing the determination of BC residues in a variety of foods including 14 items in a concentration range of 9.0 to 405.0 pg/kg with proper accuracy and precision.

This review highlights the application of oxidative and reductive chemical transformations in the structure determination of complex marine natural products, including their absolute configurations. Workability of the Baeyer-Villiger reaction, ozonolysis, periodate oxidation, hydrogenolysis, and reductive amination, as well as other related chemical transformations, are discussed.

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.

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.

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.

The facile and effective synthesis of novel cobalt (III) complex salt of composition [Co(bpy)2CO3].IO4 (where bpy=2,2’-bipyridine, IO4= periodate) was performed in aqueous medium at room temperature. The complex was characterized with wide range of analytical and spectroscopic tools such as CHN, FT-IR, UV–Vis and 1H NMR. The complex salt crystallizes in triclinic space group (P-1) with a=7.17687(12), b= 10.8056(2), c= 14.3822(3)A, α=83.4356(17)°, β=85.3108(15)°, γ=86.2535(16)°, V=1102.56(4)A3 and Z=2. The single-crystal X-ray diffraction studies revealed that the complex is six coordinated with the inner coordination sphere of the metal ion comprising of one carbonate and two 2,2’-bipyridine moieties. The crystal has distorted octahedral geometry with hydrogen bonding interactions [C‒Hδ+···Oanionδ−] existing in the crystal lattice. The thermogravimetric studies were performed to further support the coordination structure of the complex. In addition, the complex was tested for in vitro antibacterial activity against Gram-positive (S. aureus) and Gram-negative bacteria (E.coli and P. aeruginosa). The complex showed significant activity against all three bacteria tested, however S. aureus was found to be more sensitive to it, with MIC of 400 µM. Further, the complex showed good anti-cancer potential as it was able to reduce the viability of HeLa cells in a concentration dependent manner with IC50 value corresponding to 60 µM.

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....

A procedure for decomposing samples and determining rhodium in environmental objects by the catalytic method according to the reaction of sulfarsazen oxidation with periodate is proposed. The accuracy of the results is confirmed by determining rhodium using the method of inductively coupled plasma mass spectrometry. It is established that the rhodium content in the samples of road dust in Moscow is 0.01–0.04 g/t depending on the place of sampling. The standard deviation of repetition of the results of rhodium determination does not exceed 0.05.

A new, simple, inexpensive, and fast kinetic spectrophotometric method was developed for the determination of trace amounts of antibiotic drug novobiocin sodium over the range of 4‒32 ng/mL. The method is based on the inhibitory effect of novobiocinon the reaction of Amido Black and periodate in the acidic micellar mediums. The reaction was monitored spectrophotometrically by measuring the decrease in absorbance at 627 nm and fixed-time 6 min from initiation of the reaction. The detection limit is 3 ng/mL, and relative standard deviation for 4.8 and 12 ng/mL novobiocin were 0.52 and 0.65%, respectively, for six replicate measurements. The method was applied to the determination of novobiocin in human and dog serum, urine, and milk samples.

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.

A novel chemiluminescence (CL) performance of CdTe/CdS/ZnS quantum dots (QDs) with periodate (KIO 4 ) was studied. Effects of concentration and pH on the CL system were investigated. Electron spin resonance (ESR) and the effects of radical scavenger analysis were employed for identification of intermediate species. The CL spectra for this system showed only one maximum emission peak centered around 620 nm, which was similar with photoluminescence (PL) spectra of CdTe/CdS/ZnS QDs. The CL of CdTe/CdS/ZnS QDs was induced by direct chemical oxidation and the possible mechanism could be explained by radiative recombination of injected holes and electrons. This investigation not only provided new sight into the optical characteristics of CdTe/CdS/ZnS QDs, but also broadened their potential optical utilizations.

CdS was synthesized via hydrothermal method and CdS-coated ZrO 2 composite was prepared via chemical precipitation method. And then they were characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). After that, the sonocatalytic degradation of pethidine hydrochloride (dolantin) in aqueous solution was conducted adopting CdS-coated ZrO 2 composite as sonocatalyst with inorganic oxidant assisted. In addition, some influencing factors such as inorganic oxidant kind, including persulfate (K 2 S 2 O 8 ), perchlorate (NaClO 4 ) and periodate (KIO 4 ), inorganic oxidant concentration and ultrasonic irradiation time on sonocatalytic degradation of pethidine hydrochloride were examined by using gas chromatograph. The experimental results showed that the used inorganic oxidants can effectively assisted the sonocatalytic degradation of pethidine hydrochloride caused by CdS-coated ZrO 2 composite and the increase effects arrange as the order of K 2 S 2 O 8 > KIO 4 > NaClO 4 . And the best sonocatalytic degradation ratio (95.50%) of pethidine hydrochloride could be obtained when the conditions of 10.00 mmol/L K 2 S 2 O 8 , 1.00 g/L prepared CdS-coated ZrO 2 composite, 135 min ultrasonic irradiation (40 kHz frequency and 300 W output power), 100 mL total volume and 25–28 °C temperature were adopted. However, only using CdS-coated ZrO 2 as sonocatalyst without any inorganic oxidants merely reaches 20% degradation ratio of pethidine hydrochloride when other conditions are the same. The method of sonocatalytic degradation assisted with inorganic oxidants may be an efficient sonocatalytic system for degradation of pethidine hydrochloride.

The oxidation of paper by periodate was investigated and systematically characterized by Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy, X-ray diffraction, goniometry, and dynamic mechanical analysis. For the first time, in situ FTIR microscopy analysis was performed, yielding chemical images of carbonyl groups on the cellulose fibers. The enhancement of protein immobilization on oxidized paper was quantified by a colorimetric assay with Ponceau dye, demonstrating that 0.5-h oxidation suffices to functionalize the paper-based devices. The oxidized paper was applied as a sensor for protein quantification in urine, a test able to detect levels of proteinuria and even microalbuminuria. The quantification was based on the capture of proteins through covalent bonds formed with the carbonyl groups on the oxidized paper followed by the staining of the region with Ponceau dye. There is a linear dependency between human serum albumin (HSA) concentration and the length of the stained blot from 0.1 to 3 mg mL−1. This method correlated linearly with a reference method showing a higher sensitivity (0.866 cm mL mg−1) than the latter. The limit of quantification was 0.1 mg mL−1, three times lower than that of the commercial strip.

Gold nanostar@reduced graphene oxide (GNS@rGO) nanocomposite was used as a catalyst in a chemiluminescence (CL) reaction. Composites with different sizes of gold nanostars were prepared without any surfactant, and characterized by transmission electron microscopy, UV–visible, FT-IR and Raman spectroscopy. We showed that GNS@rGO can strongly enhance the intensity of luminol‑sodium periodate CL system and the larger the GNS size, the greater the enhancing effect. This effect results from the unique catalytic action of GNS@rGO, which leads to the acceleration of reactive oxygen species generation. We also found that a remarkable increase in the CL intensity of GNS@rGO-luminol-NaIO4 system occurs in the presence of glutathione (GSH). Based on this observation, a simple and highly sensitive CL probe was developed for detection of GSH. Under the optimum conditions, the calibration curve exhibits a linear range from 1.0 nM to 1.0 μM for GSH with a detection limit of 0.2 nM. The developed method was applied to the detection of GSH in human plasma samples.

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.

ZnSe quantum dots (QDs) with a homogeneous size distribution and good stability were synthesized by the reaction of zinc acetate and NaHSe in the presence of glutathione (GSH). The obtained ZnSe QDs were characterized using transmission electron microscopy (TEM) and X-ray powder diffraction (XRD). Simultaneously, UV-visible spectroscopy (UV-vis) was performed and the fluorescence properties of ZnSe QDs were investigated. The effect of ZnSe QDs on the luminol–potassium periodate (KIO4) chemiluminescence (CL) system, a popular model CL system, was researched. It was found that as-prepared ZnSe QDs could strongly enhance the chemiluminescence (CL) of the luminol–KIO4 system. To discuss the mechanism of the CL enhancement, we studied the UV-vis and CL spectra of the luminol–KIO4–ZnSe QDs system. The CL enhancement should be attributed to the oxidation of luminol to its excited state by KIO4, under the catalysis of ZnSe QDs, which caused strong light emission. It was found that rutin, p-t-butylprocatechol, catechol, paracetamol, resorcinol and tryptophan could markedly inhibit the CL of the luminol–KIO4–ZnSe QDs system among 17 kinds of amino acids and 23 other kinds of organics. The above phenomena presented good linear relations. Thus, effective methods to detect them were developed.

In this study, the crude polysaccharide (HMP) was extracted from Hypsizygus marmoreus using water-extraction and alcohol-precipitation methods. The separation and purification were performed followed by the preparation of the homogeneous polysaccharide termed as HMP-1. The structural feature of HMP-1 was investigated by a combination of chemical and instrumental analyses. The results showed that the average molecular weight of HMP-1 was 1.92 × 103 kDa. Besides, monosaccharide composition analysis showed that the HMP-1 mainly consist of d -mannose, d -glucose and d -galactose in the molar ratio of 1.145:5.282:1.157. The periodate oxidation, smith degradation and methylation results revealed that the main chain of HMP-1 was composed by →4)-D-Glcp-(1→, →6)-D-Galp-(1→, →4,6)-D-Glcp-(1→ and D-Glcp-(1→, while the side chain was →3)-D-Manp-(1→, D-Manp-(1→ and D-Glcp-(1 → . α-Glucosidase inhibitory activity experiment result showed that HMP-1 was able to inhibit the activity of α-glucosidase. Therefore, as the chemical structure and biological activity of HMP-1 were clearly characterized, Hypsizygus marmoreus can be used as a reference source for drug preparations.

For the first time, polyaldehyde kefiran was applied to immobilize the pectinase on the glass bead and the finding was compared with free enzyme. Polyaldehyde kefiran, produced by periodate oxidation of kefiran, showed an aldehyde content of 23.6 ± 0.9% that was confirmed by FTIR. The results showed although the optimum temperature (50 °C) was not changed by immobilization, the optimum pH was shifted from 5.0 to 5.5. In optimal conditions, the specific activity of the free and immobilized pectinase was 2.93 ± 0.13 and 1.87 ± 0.24 unit/mg, respectively. Also, the immobilized pectinase had a higher thermal and pH stability than free enzyme. Km and Vmax of the immobilized pectinase were higher and lower than the free enzyme, respectively. In addition, SEM and AFM images illustrated a completely non-uniform surface after enzyme immobilization on the glass bead, which seemed to be related to the polyaldehyde kefiran strands.

We discussed the trends, analytical applications and future directions of periodate-peroxide chemiluminescence (CL) systems. New strategies and developments have been discussed to improve the selectivity and sensitivity for applications in different areas such as pharmaceutical, clinical, food and environmental assessment. Moreover, a brief summary, the different mechanism in the presence of various enhancers, the drawbacks of the present studies and future prospect of periodate-peroxide CL system is provided. Additionally, we assess what could be the next generation of CL based technologies. This review sums up the periodate oxidation to the development of CL on the successful fabrication of sensors and labeling techniques.

Stable and low-cost carbon dots (C-dots) were prepared from polyethylenimine (PEI) by a hydrothermal method. It is found that the fluorescence of the C-dots (best measured at excitation/emission wavelengths of 365/473 nm) is quenched by selective oxidation of surface PEI by periodate but recovers in the presence of uric acid (UA). It is assumed that this is due to the selective reduction of the nitrone groups to hydroxylamine groups by UA. The findings were used to design a fluorometric method for determination of UA that has a 2.3 nM detection limit. This is lower than that of reported fluorometric and enzymatic assays. The performance of the method has been validated by determination of UA in samples of human saliva. It is found that the results agree well with those obtained by a commercial UA assay. Graphical abstract Schematic presentation of the polyethylenimine (PEI) carbon nanodots (C-dots) as a fluorescent probe for uric acid. Their fluorescence is quenched by periodate (IO

The structural properties and Angiotensin-I converting enzyme (ACE) inhibition activities of a polysaccharide (PGE) extracted from Gastrodia elata Blume were investigated. PGE was extracted using hot water and purified by Sephadex G-200 followed by ultra-filtration. The structural characterisation of PGE was analysed by FT–IR, NMR spectroscopy, specific rotation determination, periodate oxidation-smith degradation, methylation analysis, GC–MS and Congo red test. The results revealed that PGE was composed by glucose, with an average molecular weight of 1.54 × 103 kDa. The structure of PGE was 1→3 and 1→4,6-branched-glucopyranose that had a linear backbone of (1 → 4)-linked-d-glucopyranose (Glcp). ACE-inhibitory activity results showed that PGE was efficient to inhibit ACE and the IC50 value was 0.66 mg/mL.

We describe a simple method for non-titrimetric determination of oxidative species capable of oxidizing iodide to form free iodine. The combined action of iodine and excess iodide leads to the etching of gold nanoclusters stabilized with serum albumin. The extent of fluorescence quenching represents a direct signal for the amount of oxidative analytes. Compared to classical iodometry, tedious titration steps are not required and much smaller sample volumes are needed. This new assay provides a convenient means as demonstrated for the quantification of the oxidative analytes nitrite, bromate and periodate, with detection limits (at 3σ) of 11.7 μM, 1.7 μM, and 1.5 μM, respectively.

Glycerol is a naturally occurring polyol in the human body, essential for several metabolic processes. It is widely used in the food, pharmaceutical, and medical industries and in clinical practice as a plasma volume expander (PVE). Athletes, however, may use glycerol to mask the presence of forbidden substances or to enhance performance, inclusively through hyperhydration achieved by glycerol ingestion with added fluid. These practices are considered doping, and are prohibited by the World Anti-Doping Agency (WADA). Therefore, glycerol was introduced in the prohibited list. Doping through glycerol ingestion can readily be identified by detection of elevated glycerol concentrations in urine. In this paper, a protocol for the fast detection of glycerol in urine is proposed. It consists of a previous visual colourimetric screening, followed by a quantitative/qualitative confirmation analysis by mass spectrometry. The screening procedure involves a reaction in which polyhydric alcohols are oxidized by periodate to formic acid and formaldehyde, which is detected by the addition of a fuchsin solution. For the subsequent qualitative/quantitative confirmation analysis, a gas chromatography-mass spectrometry based approach with a non-deuterated internal standard and a drying step of only 10 min is proposed. The linear correlation was demonstrated within WADA´s threshold range. The calculated RSD were 2.1% for within-day precision and 2.8% for between-day precision. The uncertainty estimation was calculated, and a value of 2.7% was obtained. The procedure may also be used for the analysis of other polyols in urine, as for example the PVE mannitol.

The bulky-headed oxidant hexadecyltrimethylammonium periodate affords the diastereomeric pairs, (Ss)-(+)/(Rs)-(+) and (Ss)-(−)/(Rs)-(−)-neomenthyl phenyl sulfoxides in stereochemically pure states with improved diastereomeric excess (48% diastereomeric excess [de]) as compared to its nonbulky counterpart, sodium metaperiodate (28% de) from respective (+)/(−)-neomenthyl phenyl sulfides. Steric effects involving the head group volume of hexadecyltrimethylammonium periodate is found to play a role in improving the diastereomeric ratio of the products. The two diastereomers can be readily separated by column chromatography. Absolute configuration at the sulfur center in (+)-neomenthyl phenyl sulfoxide was determined by single-crystal X-ray crystallography and found to be Ss. Relative configurations of other sulfoxides were assigned based on the configuration of (+)-neomenthyl phenyl sulfoxide. Chirality 27:370–374, 2015. © 2015 Wiley Periodicals, Inc.

A postcolumn reaction system based on droplet microfluidics was developed for capillary electrophoresis (CE). Analytes were separated using capillary zone electrophoresis (CZE) and electrophoretically transferred into droplets. The use of a micro cross for positioning a salt bridge-electrode opposite the separation capillary outlet is the key element for maintaining the electrical connection during electrophoretic separation. As the first of its kind, positioning the droplets in the electric field eliminated the need for electroosmotic flow (EOF) or hydrodynamic flow for droplet compartmentalization. Depending on the total flow rate of both aqueous and oil phases, droplets of water-in-oil could be formed having frequencies between 0.7 and 3.7 Hz with a size of approximately 14 nL per droplet. Compartmentalized in the droplets, analytes reacted with reagents already present in the droplets to facilitate detection. The periodate oxidation of paralytic shellfish toxins (PSTs) was demonstrated, overcoming the limitation of precolumn oxidation, which results in multiple and sometimes identical oxidation products formed from the different PSTs. Compartmentalization allows the oxidation products for each peak to be contained and to contribute to a single fluorescence signal, preserving the selectivity of CZE separation while gaining the sensitivity of fluorescence detection.

We report on a headspace gas chromatographic method for determining the content of 3-chloro-1,2-propanediol in polyamideamine epichlorohydrin resin solution. It was based on quantitatively converting 3-chloro-1,2-propanediol to formaldehyde by periodate oxidation in a closed headspace sample vial at a room temperature for 10 min, and then to methanol by borohydride reduction at 90°C for 40 min followed by the headspace gas chromatographic measurement. The results showed that the present method has an excellent measurement precision (relative standard deviation < 2.60%) and accuracy (recoveries from 96.4-102%) in 3-chloro-1,2-propanediol analysis. The limit of quantitation was 0.031 mg/mL. It is simple and suitable for determining the 3-chloro-1,2-propanediol content in polyamideamine epichlorohydrin resin solution.

A new water-soluble heteropolysaccharide (PS-II) with apparent molecular weight ∼1.65 × 10 5 Da, was isolated from the fruiting bodies of hybrid mushroom pfle 1p by hot aqueous extraction . It is composed of d -mannose, d -galactose, and 3- O -Me- d -galactose in a molar ratio of 1.0:0.99:1.1. The structural investigation of PS-II has been carried out using acid hydrolysis, methylation analysis, periodate oxidation study, and 1D/2D NMR experiments. Based on the results of these experiments, it was established that PS-II contained a main chain of (1 → 6) linked α- d -galactopyranosyl residues, one of which was substituted at C-2 by a terminal mannopyranosyl residue and also methylated at C-3 position. This heteropolysaccharide (PS-II) exhibited macrophage activation by NO production as well as in vitro splenocyte and thymocyte stimulation.

Glyceraldehyde 3-phosphates are important intermediates of many central metabolic pathways in a large number of living organisms. d-Glyceraldehyde 3-phosphate (d-GAP) is a key intermediate during glycolysis and can as well be found in a variety of other metabolic pathways. The opposite enantiomer, l-glyceraldehyde 3-phosphate (l-GAP), has been found in a few exciting new pathways. Here, improved syntheses of enantiomerically pure glyceraldehyde 3-phosphates are reported. While d-GAP was synthesized by periodate cleavage of d-fructose 6-phosphate, l-GAP was obtained by enzymatic phosphorylation of l-glyceraldehyde. (1)H- and (31)P NMR spectroscopy was applied in order to examine pH-dependent behavior of GAP over time and to identify potential degradation products. It was found that GAP is stable in acidic aqueous solution below pH 4. At pH 7, methylglyoxal is formed, whereas under alkaline conditions, the formation of lactic acid could be observed.

An improved periodate/Schiff's base based fluorescent stain with dansylhydrazine (DH) for glycoproteins in 1D and 2D SDS-PAGE was described. Down to 4-8 ng of glycoproteins can be selectively detected within 2 h, which is approximately 16-fold higher than that of original protocol, but similar to that of Pro-Q Emerald 488 stain (Invitrogen, Carlsbad, USA). Furthermore, subsequent study of deglycosylation, glycoprotein affinity isolation, and LC-MS/MS analysis were performed to confirm the specificity of the improved method. As a result, improved DH stain may provide a new choice for selective, economic, MS compatible, and convenient visualization of gel-separated glycoproteins.

A practical synthesis of the very rare sugar d-idose and the stable building blocks for d-idose, d-iduronic, and d-idonic acids from ido-heptonic acid requires only isopropylidene protection, Shing silica gel-supported periodate cleavage of the C6-C7 bond of the heptonic acid, and selective reduction of C1 and/or C6. d-Idose is the most unstable of all the aldohexoses and a stable precursor which be stored and then converted under very mild conditions into d-idose is easily prepared.

The impact of the chip design and the mixing mechanisms using six different 3D printed microfluidic chips were investigated. The study was conducted using novel 3D printed droplet based microfluidics. A multi-mixing approach was utilized to enhance the CL signal of the CL system under investigation. The approach is based on droplet formation, droplet mixing and droplets merging in the 3D printed microfluidic chip. A 154% higher CL signal intensity was obtained using this approach compared to the CL signal obtained using the serpentine chip commonly used for improving the mixing inside droplet microfluidics. This chip was exploited to study the role of three metal ions: Co2+, Mn2+ and Fe2+ on catalyzing the luminol‑potassium periodate chemiluminescence (CL) reaction with selected phenolic compounds in basic media was carefully investigated. Furthermore, the luminol‑potassium periodate-metal ions system was optimized for all metal ions using gallic acid as the reference standard. Despite the popularity of luminol systems in estimating antioxidant activity or total phenolic content (TPC), the results of this study revealed the necessity of careful and vigilant attention when applying it to complex matrices. The only metal ion that showed quenching behavior with all 20 of the tested phenolic compounds was Fe2+, while Co2+and Mn2+ showed both quenching and enhancement in the CL signal. The luminol‑potassium periodate-Fe2+ system was applied to estimate TPC in olive oil extracts.

The highly viscous neutral exopolysaccharide, produced in large amounts by Lactobacillus fermentum TDS030603 in MRS broth and in a chemically defined medium supplemented with glucose, was investigated by GLC(-EIMS) monosaccharide and methylation analysis, periodate oxidation, MALDI-TOF mass spectrometry, and 1D/2D NMR spectroscopy. The GLC(-EIMS) analyses showed that the EPS contained d -glucose and d -galactose in an averaged molar ratio of 2.6:1.0, consisting of terminal d -Glc p , 3-substituted d -Glc p , 2,3-disubstituted d -Glc p , and 6-substituted d -Gal p in an averaged molar ratio of 1.3:1.0:1.1:1.1, with a trace of terminal d -Gal p (0.1). Combined with the NMR data of the EPS (previously reported constituent analysis: terminal Glc p , 3-substituted Glc p , 2,3-disubstituted Glc p , and 6-substituted Gal p in an averaged molar ratio of 1.2:1.1:1.0:1.1) and oligosaccharides isolated after partial acid hydrolysis, a branched tetrasaccharide repeating unit, with some heterogeneity in the side chain, having the following structure is proposed: Download full-size image

A heteroglycan (PS) isolated from the mycelia of Pleurotus ostreatus was found to consist of l-fucose, d-mannose, and d-glucose in a molar ratio of nearly 1:2:3. On the basis of acid hydrolysis, methylation analysis, periodate oxidation, and NMR studies (1H, 13C, TOCSY, DQF-COSY, NOESY, ROESY, HSQC, HMBC, and DEPT), the structure of the repeating unit of the PS was determined. The repeating unit had a branched backbone composed of (1→6)-linked α and βd-glucose and (1→2)-linked α-l-fucose. Branching occurred at C-4 position of (1→6)-linked α-d-glucopyranosyl residue with terminal β-d-mannose and C-3 position of (1→6)-linked β-d-glucopyranosyl residue with (1→6)-α-d-mannopyranosyl moiety terminated by α-d-glucose. The structure of the repeating unit of the PS was proposed as: [formula: see text]. The antioxidant properties of the PS were studied. The scavenging activity of hydroxyl free radicals whose EC50 value of PS at 943 μg/mL was determined. Further, EC50 value of the PS at 53 μg/mL was observed for scavenging activity of superoxide free radicals. Chelating effects (54.82%) of ferrous ions were observed at 1mg/mL of the PS.

A novel chemiluminescence (CL) reaction was based on the oxidizing reaction of luminol by the trivalent copper-periodate complex (K5[Cu(HIO6)2], DPC) in alkaline medium. The CL intensity could be enhanced in the presence of amikacin sulfate (AKS). A new CL method was developed for the determination of AKS by coupling with flow injection (FI) technology. Because of the distinctive oxidative effect of DPC, the luminol-based CL reaction could occur at a low concentration of 10â7M. The relative CL intensity was proportional to the concentration of AKS in the range of 4.0Ã10â9â4.0Ã10â6g/mL with the detection limit of 1.2Ã10â9g/mL. The relative standard deviation was 2.1% for 8.0Ã10â9g/mL AKS (n=9). The proposed method was successfully applied to the direct determination of AKS at the level of ng/mL in serum samples. The recovery varied from 97.0% to 106.3%. A possible mechanism of the CL reaction was discussed in detail by relating to the CL kinetic characteristics and electrochemical activities of the oxidant DPC. Keywords: Amikacin sulfate, Chemiluminescence, K5[Cu(HIO6)2], Flow injection, Serum sample

A water soluble glucan (PS-I) was isolated from the hot aqueous extract of the fruit bodies of an ectomycorrhizal edible mushroom, Russula albonigra (Krombh.) Fr. The total hydrolysis, methylation analysis, periodate oxidation, and NMR ((1)H, (13)C, DEPT-135, TOCSY, DQF-COSY, NOESY, ROESY, HSQC, and HMBC) studies revealed the presence of the following repeating unit in the polysaccharide: This glucan showed excellent activation of macrophages as well as splenocytes and thymocytes in vitro.

An immunoenhancing water-soluble hetero polysaccharide was isolated from an alkaline extract of the fruit bodies of an ectomycorrhizal edible mushroom, Tricholoma crassum (Berk.) Sacc. The structure of the molecule was investigated using acid hydrolysis, methylation analysis; periodate oxidation study, and NMR spectroscopy techniques ((1)H, (13)C, DEPT-135, DQF-COSY, TOCSY, NOESY, ROESY, HSQC, and HMBC). On the basis of the above-mentioned experiments the structure of the repeating unit of the polysaccharide was established as: This polysaccharide exhibited splenocyte, thymocyte as well as macrophage activations.

A water soluble polysaccharide isolated from the hot water extract of the unripe fruits of Manilkara zapota L. was found to consist of 3-O-acyl- l -rhamnose, l -arabinose, 3-O-acetyl- d -methyl galacturonate in a molar proportion of nearly 1:1:1. Structural investigation of the polysaccharide was carried out using total hydrolysis, methylation analysis; periodate oxidation followed by GLC–MS, and NMR experiments. On the basis of the above experiments it is concluded that the following repeating unit is present in the polysaccharide. Download : Download full-size image

This paper describes a sensitive spectrophotometric method developed for determination of Ketoconazole (KC) in tablets based on amplification reactions. Ketoconazole was oxidized with periodate, resulting in formation of KC2+ and iodate ions. After masking the excess periodate with molybdate, the iodate was treated with iodide to release iodine. The liberated iodine was transformed to ICl2â species and extracted as ion-pair with rhodamine 6G into toluene for spectrophotometric measurement at 535 nm. A linear calibration graph was obtained between 0.2136 μg/mL and 1.7088 μg/mL of Ketoconazole with a molar absorptivity of 5Ã105 mol·Lâ1 cmâ1. The procedure was successfully applied for the determination of ketoconazole in tablet formulation. Keywords: Ketoconazole, Spectrophotometry, Amplification, Periodate, Oxidation

In this study, a simple and sensitive induction period based kinetic spectrophotometric method is reported for determination of trace amounts of piroxicam (PX). This method is based upon the inhibition effect of PX on the catalytic oxidation of m-creosol purple (MCP) with periodate. In the presence of PX, an induction period appears in the reaction system, which is proportional to the PX concentration. The decolorization of MCP at 525 nm is used to monitor the reaction spectrophotometrically. Under the optimum conditions, PX can be determined in the range of 1–12.5 μM (0.33–4.14 μg mL-1), with a 3σ detection limit of 0.54 μM (0.18μg mL-1). The relative standard deviations for six replicate determinations of 1.25, 5.0, and 10.0 μM piroxicam are 1.03 %, 0.28 %, and 0.22 %, respectively. This method could successfully be used in the determination of PX in various pharmaceutical products.

A new sensitized chemiluminescence (CL) was developed to broaden the analytical application of KIO4-H2O2 system. The nitrogen doped carbon dots (N-CDs) dramatically boosted the CL intensity of KIO4-H2O2 system which was further enriched by basic medium. In light of EPR analysis, free radical scavenging studies and CL spectra the detail mechanism for the enhancement was conferred in the presence of N-CDs and NaOH. The results suggested that CL of KIO4-H2O2 system in the presence and absence of N-CDs and NaOH proceeds via radical pathway. The enhanced CL was used for the determination of pyrogallol and gallic acid in range of 1.0×10(-4)-1.0×10(-7)M with 4.6×10(-8) and 6.1×10(-8)M limit of detection respectively. The relative standard deviation (RSD) at a concentration of 10(-5) for gallic acid and pyrogallol was 1.4% and 2.3% respectively (n=11). The attained results unveil that the present method is sensitive, faster, simpler and less costly compared to other methods and could be applied to determine polyphenols in real samples.

A water-soluble α β-glucan with a molecular weight of 1.62 × 10(5) Da, AAPS -1, was obtained from the fruiting bodies of the edible mushroom Auricularia polytricha by a combined separation of high-speed countercurrent chromatography (HSCCC)-Sephacryl S-300 HR column chromatography. The structure of AAPS-1 was elucidated that the polysaccharide possesses a backbone composed of (1 → 6)-linked-α-D-glucopyranosyl and (1 → 6)-linked-β-D-glucopyranosyl residues, partially substituted at O-3 of β-D-glucopyranosyl residue by side chain (1 → 4)-α-D-Glcp and terminated with non-reducing end α-D-Glcp-(1 → on the basis of the analyses of partial hydrolysis, periodate oxidation, acetylation, methylation and NMR spectroscopy ((1)H, (13)C).

The Astragalus polysaccharide (APS) was extracted and purified from the roots of Astragalus membranaceus, and characterised for its chemical structure and potential health properties. The APS was composed of α- d -glc residues with the estimated equivalent dextran molecular weight of 2.07 × 104 Da. Periodate oxidation analysis, 1D and 2D NMR spectroscopy demonstrated that APS has repeating (1 → 4)-linked backbone with a (1 → 6)-linked branch every 10 residues. The APS possessed scavenging activities against hydroxyl radicals and hydrogen peroxide, and showed chelating effect on ferrous ions. The APS was also able to bind cholic and chenodeoxycholic acids in vitro. In addition, APS was able to stimulate activity of purified mouse B cells without promoting T cell proliferation. These data provided information for future development of APS as a nutraceutical.

A water-soluble glucan, isolated from the alkaline extract of the fruit bodies of an edible mushroom, Lentinus squarrosulus (Mont.) Singer was found to consist of (1→3,6)-linked, (1→3)-linked, (1→6)-linked, and terminal β- d -glucopyranosyl moieties in a relative proportion of approximately 1:2:1:1. This polysaccharide showed optimum activation of macrophages as well as splenocytes and thymocytes at 10 μg/mL. Structural investigation was carried out using sugar analysis, methylation analysis, periodate oxidation study, and NMR experiments ( 1 H, 13 C, DEPT-135, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC). On the basis of above-mentioned experiments, the structure of the repeating unit of the polysaccharide was established as

In the present study, we synthesized dextran (MW = ca. 2,000 kDa)-based macromolecular probes containing multiple molecules of alkaline phosphatase (ALP) as a signal-trigger enzyme and of biotin as an assembly mediator. The ALP and biotin molecules were covalently attached into the dextran backbone after the formation of aldehyde groups into the macromolecule by periodate oxidation. The synthesized probes contained 27-31 molecules of ALP in their macromolecules when 50-fold molar ratio of ALP to the dextran was used for the synthesis. These probes provided 14-20 times stronger chemiluminescence (CL) than that of the equimolar free ALP adsorbed on a nylon membrane. The velocity of the CL reaction of ALP-catalyzed adamantlyl-1,2-dioxetane substrate was improved from a slower emission (glow type) of CL to a faster one (flash type). The CL signal integrated for 2 min under strongly alkaline conditions (pH 13.0) was about ten times greater than that obtained by the conventional conditions (pH 9.5). Therefore, the synthesized macromolecular probe could be successfully utilized for the high-throughput CL detection of biotin-conjugated anti-rabbit IgG antibody with a lower detection limit of 880 amol per spot on the nylon membrane. This study provides analytical strategy for the rapid, convenient, and sensitive detection of target proteins in immunoassays.

Detailed elemental composition and distribution of sulfides and thiophenic compounds in four subfractions of Kazakhstan vacuum gas oil (VGO) were determined by positive ion electrospray (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The sulfides in VGO subfractions were selectively oxidized into sulfoxides using tetrabutylammonium periodate (TBAPI). The sulfur compounds in the oxidized VGO subfractions were reacted by methylation to form methylsulfonium salts and were then characterized. Elemental composition and distribution of sulfides and thiophenic compounds in the VGO subfractions were characterized by their double bond equivalents (DBE) values and carbon numbers before and after the oxidation reactions. The results showed that the S1 class species with DBE values of 6 and greater are likely thiophenic compounds, while those with DBE values less than 6 are sulfides. As boiling point of VGO increased, the abundance of thiophenic compounds increased. DBE value and carbon...

The oxidation of N,N-dimethylethanolamine (DMEA) by bis(hydrogenperiodato) argentate(III) ([Ag(HIO6)2]5−) was studied in aqueous alkaline medium. Formaldehyde and dimethylamine were identified as the major oxidation products after the oxidation of DMEA. The oxidation kinetics was followed spectrophotometrically in the temperature range of 25.0 °C–40.0 °C. It was found that the reaction was first order in [Ag(III)]; the oberved first-order rate constants kobsd as functions of [DMEA], [OH−] and total concentration of periodate (\([\mathrm{IO}_{4}^{-}]_{\mathrm{tot}}\)) were analyzed and were revealed to follow a rate expression: \(k_{\mathrm{obsd}} = (k_{1} +k_{2}[\mathrm{OH}^{-}])K_{1}K_{2}[\mathrm{DMEA}]/\{f([\mathrm{OH}^{-}])[\mathrm{IO}_{4}^{-}]_{\mathrm{tot}}+ K_{1} + K_{1}K_{2}[\mathrm{DMEA}]\}\). Rate constants k1 and k2 and equilibrium constant K2 were derived; activation parameters corresponding to k1 and k2 were computed. In the proposed reaction mechanism, a peridato-Ag(III)-DMEA ternary complex is formed indirectly through a reactive intermediate species [Ag(HIO6)(OH)(H2O)]2−. In subsequent rate-determining steps as described by k1 and k2, the ternary complex decays to Ag(I) through two reaction pathways: one of which is spontaneous and the other is prompted by an OH−.

An on-site determination method for trace manganese has been developed using the manganese-catalyzed oxidation of Malachite Green (MG) with potassium periodate. Absorbance measurement of MG was carried out using a laboratory-made palm-top size colorimeter with a red-green-blue light-emitting diode. The reciprocal value (1/τ) of the reaction time at a fixed absorbance value for red light was chosen as a kinetic parameter for simple on-site analyses. The value of 1/τ was proportional to the concentration of manganese in the range of 2 - 20 µg L(-1). At a reaction temperature (T) of 20°C or more, manganese was determined within a reaction time of 25 min. The calibration equation was approximated by 1/τ = (aT + b)[Mn] + (cT + d), where a to d were constants in a range of 10 - 40°C. The two equations for 30°C (for the laboratory-preparation of the calibration equation) and T give the value of 1/τ at 30°C as 1/τ(f) = (30a + b)(1/τ - cT - d)/(aT + b) + 30c + d. Without any temperature control, 1/τ(f) can be calculated by this equation and measurements of 1/τ and T. The calculation introduced analytical errors of within 1 µg L(-1). The proposed method was successfully applied to tap-, river- and lake-water samples.