The protection of polysaccharide from the Brown Seaweed Sargassum graminifolium against ethylene glycol-induced mitochondrial damage.

The aim of the present study is to evaluate the protective effect of polysaccharide from the Brown Seaweed Sargassum graminifolium (SGP) on ethylene glycol-induced kidney damage and the mechanism of SGP-mediated protection. Mitochondrial lipid peroxidation, mitochondrial swelling, the activity of succinate dehydrogenase (SDH), ATPases and mitochondrial antioxidant enzymes was observed in hyperoxaluric rats. Administration of SGP (25, 100 and 400 mg·kg-1, intragastrically) increased the activities of antioxidant enzymes, SDH and Na+/K+-ATPases, Ca2+-ATPases, Mg2+-ATPases, also decreased mitochondrial lipid peroxidation and mitochondrial swelling. SGP exhibited a protective effect by improving antioxidant enzymes and restoring mitochondrial dysfunction in the kidney of hyperoxaluric rats. It may be used as a promising therapeutic agent to provide superior renal protection.

Application of portable gas chromatography-photo ionization detector combined with headspace sampling for field analysis of benzene, toluene, ethylbenzene, and xylene in soils.

A method based on headspace (HS) sampling coupling with portable gas chromatography (GC) with photo ionization detector (PID) was developed for rapid determination of benzene, toluene, ethylbenzene, and xylenes (BTEX) in soils. Optimal conditions for HS gas sampling procedure were determined, and the influence of soil organic matter on the recovery of BTEX from soil was investigated using five representative Chinese soils. The results showed that the HS-portable-GC-PID method could be effectively operated at ambient temperature, and the addition of 15 ml of saturated NaCl solution in a 40-ml sampling vial and 60 s of shaking time for sample solution were optimum for the HS gas sampling procedure. The recoveries of each BTEX in soils ranged from 87.2 to 105.1 %, with relative standard deviations varying from 5.3 to 7.8 %. Good linearity was obtained for all BTEX compounds, and the detection limits were in the 0.1 to 0.8 µg kg(-1) range. Soil organic matter was identified as one of the principal elements that affect the HS gas sampling of BTEX in soils. The HS-portable-GC-PID method was successfully applied for field determination of benzene and toluene in soils of a former chemical plant in Jilin City, northeast China. Considering its satisfactory repeatability and reproducibility and particular suitability to be operated in ambient environment, HS sampling coupling with portable GC-PID is, therefore, recommended to be a suitable screening tool for rapid on-site determination of BTEX in soils.

Antioxidant properties of polysaccharide from the brown seaweed Sargassum graminifolium (Turn.), and its effects on calcium oxalate crystallization.

We investigated the effects of polysaccharides from the brown seaweed Sargassum graminifolium (Turn.) (SGP) on calcium oxalate crystallization, and determined its antioxidant activities. To examine the effects of SGP on calcium oxalate crystallization, we monitored nucleation and aggregation of calcium oxalate monohydrate crystals, using trisodium citrate as a positive control. We assessed antioxidant activities of SGP by determining its reducing power, its ability to scavenge superoxide radicals, and its activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The nucleation inhibition ratio of trisodium citrate and SGP was 58.5 and 69.2%, respectively, and crystal aggregation was inhibited by 71.4 and 76.8%, respectively. Increasing concentrations of SGP resulted in increased scavenging of superoxide anions and DPPH radicals (IC50 = 1.9 and 0.6 mg/mL, respectively). These results suggest that SGP could be a candidate for treating urinary stones because of its ability to inhibit calcium oxalate crystallization and its antioxidant properties.

Bis[µ-4-methyl-2-(2-pyridyl-methyl-sulfan-yl)pyrimidine-κN]bis-[(trifluoro-methanesulfonato-κO)silver(I)].

In the centrosymmetric dinuclear title complex, [Ag(2)(CF(3)SO(3))(2)(C(11)H(11)N(3)S)(2)], the Ag(I) atom is coordinated by two N atoms from two 4-methyl-2-(2-pyridyl-methyl-sulfan-yl)pyrimidine ligands and one O atom from a trifluoro-methane-sulfonate anion in a distorted T-type coordination geometry. The ligand adopts a bidentate bridging coordination mode through one pyridyl N atom and one pyrimidine N atom. In the crystal structure, π-π inter-actions are present between adjacent pyrimidine rings, with a centroid-to-centroid distance of 3.875 (7) Å.

Tetra-aqua-bis(3-carboxyl-atopyridine N-oxide-κO)cadmium(II).

In the title complex, [Cd(C(6)H(4)NO(3))(2)(H(2)O)(4)], the Cd(II) atom is situated on a crystallographic centre of inversion. The Cd(II) atom shows a slightly distorted octa-hedral geometry and is coordinated by four O atoms from water mol-ecules and two O atoms from deprotonated carboxyl groups of nicotinic acid N-oxide ligands. The mononuclear complex mol-ecules are linked by O-H⋯O hydrogen bonds, forming a three-dimensional network structure.

A one-dimensional cadmium(II) complex supported by a sulfur-nitro-gen mixed-donor ligand.

In the title compound, catena-poly[cadmium(II)-bis-(µ-5-am-ino-1,3,4-thia-diazole-2-thiol-ato)-κ(2)N(3):S(2);κ(2)S(2):N(3)], [Cd(C(2)H(2)N(3)S(2))(2)](n), the Cd(II) ion is coordinated by two N atoms of the 1,3,4-thia-diazole rings from two ligands and two S atoms of sulfhydryl from two other ligands in a slightly distorted tetra-hedral geometry. The ligands bridge Cd(II) ions, forming one-dimensional chains along [001], which are connected by N-H⋯N and N-H⋯S hydrogen bonds into a three-dimensional network.

2,2'-[o-Phenylenebis(methylenethio)]bis(pyridine N-oxide).

In the title compound, C(18)H(16)N(2)O(2)S(2), the benzene ring makes dihedral angles of 7.41 and 86.59° with the two outer pyridine N-oxygen rings. Two short intramolecular C-H⋯S contacts occur. The crystal packing is stabilized by C-H⋯O hydrogen bonds, C-H⋯π inter-actions and weak π-π staking inter-actions [centroid-centroid distance 3.7596 (7) Å].

Bis(5,6-dicarboxy-benzimidazolium) sulfate monohydrate.

In the title compound, 2C(9)H(7)N(2)O(4) (+)·SO(4) (2-)·H(2)O, the sulfate S atom and the water O atom reside on a crystallographic twofold axis. In the crystal, the component species are linked by N-H⋯O, O-H⋯O and C-H⋯O hydrogen bonds, forming a three-dimensional network structure. An intramol-ecular O-H⋯O link is seen in the cation.

Tetra-µ-acetato-bis-[(pyridine N-oxide)copper(II)](Cu-Cu).

The mol-ecule of the title binuclear copper(II) complex, [Cu(2)(CH(3)COO)(4)(C(5)H(5)NO)(2)], occupies a special position on a crystallographic inversion centre; the coordination environment of the Cu(II) atom is slightly distorted square-pyramidal and is made up of four O atoms belonging to four acetate groups in the basal plane with the O atom of pyridine N-oxide ligand in the apical position. The Cu-Cu distance is 2.6376 (6) Å.

2,2'-[Ethane-1,2-diylbis(sulfanedi-yl)]bis-(pyridine N-oxide).

The tile compound, C(12)H(12)N(2)O(2)S(2), lies on an inversion center. The two pyridyl rings are parallel to each other. The structure is devoid of any classical hydrogen bonds due to lack of appropriate donors and acceptors for such bonds. However, non-classical hydrogen bonds of the types C-H⋯O and C-H⋯S stabilize the structure.

catena-Poly[silver(I)-µ-pyrazolato-κN:N'].

The title compound, [Ag(C(3)H(3)N(2))](n), has an infinite helical chain structure in which each pyrazolate group bridges two Ag(I) atoms related by a 2(1) axis with an intra-chain Ag⋯Ag separation of 3.3718 (7) Å. Each Ag(I) center is linearly coordinated by two N atoms [N-Ag-N angle = 169.98 (14)°]. The chains are held together by inter-chain Ag⋯Ag inter-actions [3.2547 (6) Å], forming a two-dimensional layer. The X-ray single-crystal diffraction result is consonant with that of the ab initio X-ray powder diffraction reported by Masciocchi, Moret, Cairati, Sironi, Ardizzoia & La Monica [J. Am. Chem. Soc. (1994). 116, 7668-7676], with only minor deviations of structural parameters.

Penta-aqua-(1H-benzimidazole-5,6-di-carboxyl-ato-κN)copper(II) penta-hydrate.

The title compound, [Cu(C(9)H(4)N(2)O(4))(H(2)O)(5)]·5H(2)O, contains one crystallographically independent Cu(II) atom and one 1H-benzimidazole-5,6-dicarboxyl-ate (bdc) ligand, along with five coordinated and five uncoordinated water mol-ecules. The Cu(II) atom is six-coordinated by one N atom from the bdc ligand and five O atoms from water mol-ecules, giving an octa-hedral coordination geometry. Hydrogen bonds link the mononuclear complex and uncoordinated water mol-ecules into a three-dimensional network.

Tetra-aqua-hexa-kis(µ(2)-quinoline-4-carboxyl-ato)diyttrium(III) dihydrate.

In the title centrosymmetric binuclear complex, [Y(2)(C(10)H(6)NO(2))(6)(H(2)O)(4)]·2H(2)O, each Y(III) atom is nine-coordin-ated by nine O atoms from five ligands and two water mol-ecules in a slightly distorted monocapped square-anti-prismatic coordination environment. The Y(III) atoms are separated by a distance of 4.0363 (9) Å. The ligands coordinate in three different modes: chelating, bridging and a mixed chelating bridging mode. In the crystal structure, the binuclear complexes are linked by O-H⋯O and O-H⋯N hydrogen bonds, forming a three-dimensional network.

Embedment of Ag(I)-organic frameworks into silica gels for microextraction of polybrominated diphenyl ethers in soils.

Three Ag(I)-organic frameworks, [Ag5(pydc)2(CN)]n, {[Ag4(pydc)2]CH3CN}n, and [Ag(4,4'-bpy)NO3]n, were synthesized and embedded into silica gels to form metal-organic-framework (MOF)-embedded gels for the microextraction of polybrominated diphenyl ethers (PBDEs) in soils. Despite the great differences in the structures of the organic ligands, all three Ag(I)-organic frameworks were found to effectively accumulate and concentrate PBDEs from sample solutions prepared with contaminated soil and purified water, indicating the important roles of Ag centers in PBDE extraction. Under the optimal experimental conditions (MOF mass, water volume, temperature, extraction time, and back-extraction time) for PBDE extraction from sample solutions, the detection limits of seven PBDEs (BDE-28, 47, 99, 100, 153, 154, and 183) ranged from 0.01 to 2.6ngg(-1) for [Ag5(pydc)2(CN)]n, 0.20-0.64ngg(-1) for {[Ag4(pydc)2]CH3CN}n, and 0.60-3.08ngg(-1) for [Ag(4,4'-bpy)NO3]n. The reproducibilities of the three methods were all satisfactory with relative standard deviations (RSDs) in the range of 2.2-9.6%, 5.3-10.4%, and 6.9-9.4% for [Ag5(pydc)2(CN)]n, {[Ag4(pydc)2]CH3CN}n, and [Ag(4,4'-bpy)NO3]n, respectively. The use of Ag(I)-organic frameworks for the microextraction of PBDEs was validated using both certified reference soils and field-contaminated soils, and the proposed methods are recommended as rapid and environmentally friendly alternatives for the extraction and determination of PBDEs in soils.

Separations of substituted benzenes and polycyclic aromatic hydrocarbons using normal- and reverse-phase high performance liquid chromatography with UiO-66 as the stationary phase.

Metal-organic frameworks (MOFs) have great potential for applications in chromatography due to their highly tailorable porous structures and unique properties. In this work, the stable MOF UiO-66 was evaluated as both a normal-phase (NP-) and a reverse-phase (RP-) stationary phase in the high performance liquid chromatography (HPLC) to separate substituted benzenes (SBs) and polycyclic aromatic hydrocarbons (PAHs). It was found that the mobile phase composition has a significant effect on the HPLC separation. Baseline RP-HPLC separations of xylene isomers; naphthalene and anthracene; naphthalene and chrysene; and naphthalene, fluorene, and chrysene were achieved using MeOH/H2O ratios of 80:20, 75:25, 85:15, and 75:25, respectively, on the UiO-66 column. Similarly, baseline NP-HPLC separations of xylene isomers and ethylbenzene; ethylbenzene, styrene, o-xylene, and m-xylene; and several PAHs were also obtained on the UiO-66 column with different mobile phase compositions. The relative standard deviations (RSDs) of retention time, peak height, peak area, and half peak width for five replicate separations of the tested analytes were within the ranges 0.2-0.4%, 0.2-1.6%, 0.7-3.9%, 0.4-1.1%, respectively. We also evaluated other critical HPLC parameters, including injected sample mass, column temperature, and the thermodynamic characters of both the RP-HPLC and the NP-HPLC separation processes. It was confirmed that the separation of SBs on a UiO-66 column was an exothermic process, controlled by both enthalpy change (ΔH) and entropy change (ΔS). The reverse shape selectivity, size selectivity, stacking effect, and electrostatic force played vital roles in the separations of these analytes. To the best of our knowledge, this method is one of the very few examples of using MOFs as the stationary phase in both NP-HPLC and RP-HPLC. MOF-based stationary phases may thus be applied in the separations and analyses of SBs and PAHs in environmental samples.

[Human health risk-based environmental criteria for soil: a comparative study between countries and implication for China].

Since the 1990s, most developed countries have issued the risk-based environmental standards or criteria for soil, as well as corresponding technical background documents, this provides methodological references for developing soil environmental standards and criteria in developing countries. However, because of the variability in legislation frameworks, derivation procedures of criteria, environmental conditions and climates, soil types, and habits and customs among countries, there are great differences in the names, roles and values of soil standards and criteria. This paper presents the scientific basis and fundamental features of soil environmental criteria. The definitions, functions and values of the soil environmental criteria in different countries were compared and analyzed. Key technologies for the development of soil environmental criteria and critical influence factors were summarized and analyzed, with special respect to the classification of land use types, setting of exposure scenarios and pathways, selection of acceptable risk levels for carcinogens, and the determination of exposure parameters. Strategies and countermeasures for the development of local or regional soil environmental criteria in China were proposed by referring to international experiences, and the current difficulties and challenges faced by China in the development of soil environmental criteria were discussed and addressed.

The use of copper(II) isonicotinate-based micro-solid-phase extraction for the analysis of polybrominated diphenyl ethers in soils.

A micro-solid-phase extraction (µ-SPE) device was developed by filling copper(II) isonicotinate coordination polymer (Cu(4-C(5)H(4)N-COO)(2)(H(2)O)(4)) into a porous polypropylene envelope, and the µ-SPE, coupling with gas chromatography (GC) with a micro-cell electron capture detector (µ-ECD), was used for extraction and determination of PBDEs in soils. Variables affecting extraction procedures, including temperature, water volume, extraction time, and desorption time, were investigated in a spiked soil, and the parameters were optimized. Under the optimal experimental conditions, the method detection limits for seven PBDEs (BDE-28, 47, 99, 100, 153, 154, and 183) were in the range of 0.026-0.066 ng g(-1), and the reproducibility was satisfactory with the relative standard deviation in range of 1.3-10.1%. Good linear relationship between PBDEs concentrations and GC signals (defined as peak area) was obtained in the range between 0.1 and 200 ng g(-1). The recovery of the seven PBDEs by µ-SPE varied from 70 to 90%, which was comparable to that determined by accelerated solvent extraction method. Finally, the proposed method was used to determine PBDEs in several field-contaminated soils, and it was suggested that the µ-SPE is a promising alternative microextraction technique for the detection of PBDEs in soils.