Large-pore covalent organic framework as solid phase extraction absorbentforefficientdetermination of polypeptide antibiotics in animal-derived foods.

The precise determination of polypeptide antibiotics (PPTs) in foods has been always challenging because of the interference of various endogenous peptides in complex matrix. Herin, a novel large-pore covalent organic framework (TABPT-SPDA-COF) with accessible pore size of 7.9 nm was synthesized as a solid phase extraction (SPE) absorbent for efficiently enriching four PPTs existed in foods originating from animals. The parameters of SPE process were systematically optimized. Subsequently, four PPTs were determined by UHPLC-MS/MS. Under the optimal conditions, TABPT-SPDA-COF shows outstanding enrichment capacity for PPTs in contrast to commercial absorbents ascribed to size selectivity and multiple interaction effects. The method exhibits excellent linear range (0.005-100 ng mL-1), satisfactory limits of detection (0.1 pg mL-1) as well as relative recoveries (86.2-116 %). This work offers a practicable platform to monitor trace PPTs from complex animal-derived foodstuffs.

Structural Change and Radical Generation of a Cadmium-Based Metal-Organic Framework Induced by an Electric Field.

Herein we report the structural change and radical generation of a cadmium-based metal-organic framework (Cd-MOF) induced by external electric fields. Under a weaker single electric field, different coordination modes of Cd-L lead to 3D → 2D structural change. Under stronger superposed electric fields, Cd-MOF was excited to produce a stable free radical. This study will provide a new avenue for the controlled assembly of MOFs.

A metal-organic cage-based nanoagent for enhanced photodynamic antitumor therapy.

Herein, we report, for the first time, a Pd6L8(NO3)5.4(ICG)6.6 (ICG = indocyanine green) cage-based hexagonal nanoplate (3) via a combined nanoprecipitation and solid-state anion-exchange approach. Nanoplate 3 possesses enhanced near-infrared (NIR) light-triggered 1O2 generation, high cellular uptake selective lysosome-targeting ability, and, consequently, excellent antineoplastic activity.

Synthesis, crystal structures, antiproliferative activities and reverse docking studies of eight novel Schiff bases derived from benzil.

Eight novel Schiff bases derived from benzil dihydrazone (BDH) or benzil monohydrazone (BMH) and four fused-ring carbonyl compounds (3-formylindole, FI; 3-acetylindole, AI; 3-formyl-1-methylindole, MFI; 1-formylnaphthalene, FN) were synthesized and characterized by elemental analysis, ESI-QTOF-MS, 1H and 13C NMR spectroscopy, as well as single-crystal X-ray diffraction. They are (1Z,2Z)-1,2-bis{(E)-[(1H-indol-3-yl)methylidene]hydrazinylidene}-1,2-diphenylethane (BDHFI), C32H24N6, (1Z,2Z)-1,2-bis{(E)-[1-(1H-indol-3-yl)ethylidene]hydrazinylidene}-1,2-diphenylethane (BDHAI), C34H28N6, (1Z,2Z)-1,2-bis{(E)-[(1-methyl-1H-indol-3-yl)methylidene]hydrazinylidene}-1,2-diphenylethane (BMHMFI) acetonitrile hemisolvate, C34H28N6·0.5CH3CN, (1Z,2Z)-1,2-bis{(E)-[(naphthalen-1-yl)methylidene]hydrazinylidene}-1,2-diphenylethane (BDHFN), C36H26N4, (Z)-2-{(E)-[(1H-indol-3-yl)methylidene]hydrazinylidene}-1,2-diphenylethanone (BMHFI), C23H17N3O, (Z)-2-{(E)-[1-(1H-indol-3-yl)ethylidene]hydrazinylidene}-1,2-diphenylethanone (BMHAI), C24H19N3O, (Z)-2-{(E)-[(1-methyl-1H-indol-3-yl)methylidene]hydrazinylidene}-1,2-diphenylethanone (BMHMFI), C24H19N3O, and (Z)-2-{(E)-[(naphthalen-1-yl)methylidene]hydrazinylidene}-1,2-diphenylethanone (BMHFN) C25H18N2O. Moreover, the in vitro cytotoxicity of the eight title compounds was evaluated against two tumour cell lines (A549 human lung cancer and 4T1 mouse breast cancer) and two normal cell lines (MRC-5 normal lung cells and NIH 3T3 fibroblasts) by MTT assay. The results indicate that four (BDHMFI, BDHFN, BMHMFI and BMHFN) are inactive and the other four (BDHFI, BDHAI, BMHFI and BMHAI) show severe toxicities against human A549 and mouse 4T1 cells, similar to the standard cisplatin. All the compounds exhibited weaker cytotoxicity against normal cells than cancer cells. The Swiss Target Prediction web server was applied for the prediction of protein targets. After analyzing the differences in frequency hits between these active and inactive Schiff bases, 18 probable targets were selected for reverse docking with the Surflex-dock function in SYBYL-X 2.0 software. Three target proteins, i.e. human ether-á-go-go-related (hERG) potassium channel, the inhibitor of apoptosis protein 3 and serine/threonine-protein kinase PIM1, were chosen as the targets. Finally, the ligand-based structure-activity relationships were analyzed based on the putative protein target (hERG) docking results, which will be used to design and synthesize novel hERG ion channel inhibitors.

Dinuclear cobalt and nickel complexes of a mercaptoacetic acid substituted 1,2,4-triazole ligand: syntheses, structures and urease inhibitory studies.

Because of its versatile coordination modes and strong coordination ability, the mercaptoacetic acid substituted 1,2,4-triazole 2-{[5-(pyridin-2-yl)-4H-1,2,4-triazol-3-yl]sulfanyl}acetic acid (H2L) was synthesized and characterized. Treatment of H2L with cobalt and nickel acetate afforded the dinuclear complexes {µ-3-[(carboxylatomethyl)sulfanyl]-5-(pyridin-2-yl)-4H-1,2,4-triazol-4-ido-κ2N1,N5:N2,O}bis[aqua(methanol-κO)cobalt(II)] methanol disolvate, [Co2(C9H6N4O2S)2(CH3OH)2(H2O)2]·2CH3OH (1), and {µ-3-[(carboxylatomethyl)sulfanyl]-5-(pyridin-2-yl)-4H-1,2,4-triazol-4-ido-κ2N1,N5:N2,O}bis[diaquanickel(II)] methanol disolvate dihydrate, [Ni2(C9H6N4O2S)2(H2O)4]·2CH3OH·2H2O (2), respectively. Complex 1 crystallized in the monoclinic space group P21/c, while 2 crystallized in the tetragonal space group I41/a. Single-crystal X-ray diffraction studies revealed that H2L is doubly deprotonated and acts as a tetradentate bridging ligand in complexes 1 and 2. For both of the obtained complexes, extensive hydrogen-bond interactions contribute to the formation of their three-dimensional supermolecular structures. Hirshfeld surface analysis was used to illustrate the intermolecular interactions. Additionally, the urease inhibitory activities of 1, 2 and H2L were investigated against jack bean urease, where the two complexes revealed strong urease inhibition activities.

Serum soluble TWEAK levels in severe traumatic brain injury and its prognostic significance.

BACKGROUND: Severe traumatic brain injury (sTBI) is characterized by a high mortality. Tumor necrosis factor-like weak inducer of apoptosis (TWEAK) participates in inflammation. We determined serum soluble TWEAK (sTWEAK) levels with respect to its prognostic ability. METHODS: This was a single-center prospective, observational study that was performed from December 2014 to December 2017. A total of 114 sTBI patients who met the inclusion criteria and 114 randomly selected healthy controls were included in the study. Serum sTWEAK levels were gauged. Patients were followed-up until death or completion of 6 months. Poor outcome was referred to as Glasgow outcome scale score of 1-3. RESULTS: In comparison with controls, patients displayed predominantly higher serum sTWEAK levels. Serum sTWEAK levels were strongly correlated with Glasgow coma scale scores and serum C-reactive protein levels. 32 patients (28.1%) died and 60 patients (52.6%) suffered from a poor outcome. Receiver operating characteristic curve analysis clearly showed that serum sTWEAK levels had substantially high predictive performance for 6-month mortality and poor outcome. Serum sTWEAK emerged as an independent predictor for 6-month mortality, overall survival and poor outcome. CONCLUSIONS: Raised serum sTWEAK levels are closely related to increasing inflammatory response, elevated trauma severity and worse clinical outcome after sTBI.

Nickel-metalated porous organic polymer for Suzuki-Miyaura cross-coupling reaction.

A new Ni(ii)-α-diimine-based porous organic polymer, namely Ni(ii)-α-diimine-POP, was constructed in high yield via the Sonogashira coupling reaction between the metallo-building block of Ni(ii)-α-diimine and 1,3,5-triethynylbenzene. Besides the high thermal and chemical stability, the obtained Ni(ii)-α-diimine-POP can be a highly active reusable heterogeneous catalyst to promote the Suzuki-Miyaura coupling reaction. The obtained results indicate that the Ni(ii)-α-diimine-POP herein is a promising sustainable alternative to the Pd-based catalysts for catalysing the C-C formation in a heterogeneous way.

Characterization and gas adsorption of a novel three-dimensional metal-organic framework (MOF) generated from a new polydentate fluorene-bridged ligand.

A polydentate ligand bridged by a fluorene group, namely 9,9-bis(2-hydroxyethyl)-2,7-bis(pyridin-4-yl)fluorene (L), has been prepared under solvothermal conditions in acetonitrile. Crystals of the three-dimensional metal-organic framework (MOF) poly[[[µ3-9,9-bis(2-hydroxyethyl)-2,7-bis(pyridin-4-yl)fluorene-κ3N:N':O]bis(methanol-κO)(µ-sulfato-κ2O:O')nickel(II)] methanol disolvate], {[Ni(SO4)(C27H24N2O2)(CH3OH)]·2CH3OH}n, (I), were obtained by the solvothermal reaction of L and NiSO4 in methanol. The ligand L forms a two-dimensional network in the crystallographic bc plane via two groups of O-H...N hydrogen bonds and neighbouring two-dimensional planes are completely parallel and stack to form a three-dimensional structure. In (I), the NiII ions are linked by sulfate ions through Ni-O bonds to form inorganic chains and these Ni-containing chains are linked into a three-dimensional framework via Ni-O and Ni-N bonds involving the polydentate ligand L. With one of the hydroxy groups of L coordinating to the NiII atom, the torsion angle of the hydroxyethyl group changes from that of the uncoordinated molecule. In addition, the adsorption properties of (I) with carbon dioxide were investigated.

UiO-68-ol NMOF-Based Fluorescent Sensor for Selective Detection of HClO and Its Application in Bioimaging.

Fluorescent probes are powerful tools for the investigations of reactive oxygen species (ROS) in living organisms by visualization and imaging. As one of the most important of the natural reactive oxygen species (ROS), hypochlorous acid (HClO) plays a crucial role in various physiological and pathological processes. We report herein a new redox-switchable NMOF of UiO-68-ol via a direct ligand modification approach. The obtained UiO-68-ol NPs, which contains organic-based molecular redox switches, exhibit excellent photophysical properties for biological application and can be highly sensitive and selective fluorescent probes to detect HClO species in living cells.

Copper(II)-Silver(I) Macrocyclic Metal-Organic Framework: A Highly Efficient Reusable Triplet Oxygen Collector and Singlet Oxygen Generator.

The generation of highly reactive oxygen (1O2) is very significant for a variety of applications such as degradation, bleaching, chemical synthesis, photodynamic therapy for tumor treatment, and others. Herein, we report a novel peroxide-dianion-embedded bimetallic macrocycle, [O22-@Ag4Cu4L4]2+ (2), that can completely release the inserted peroxide dianion as the singlet oxygen (1O2) via a H+-assisted disproportionation process in methanol. Notably, the resulting empty Ag4Cu4L4(ClO4)4 (3) is able to trap oxygen (3O2) from air and fixes it in the macrocycle host as a peroxide dianion; furthermore, it releases it as 1O2 again in the presence of H+. So, the bimetallic macrocycle [Ag4Cu4L4]4+ herein behaves as a highly efficient reusable triplet oxygen receptor and singlet oxygen generator.

Nanoscale UiO-MOF-based luminescent sensors for highly selective detection of cysteine and glutathione and their application in bioimaging.

We report a practical approach, the first of its kind, to construct nanoscale UiO-type metal-organic framework (Mi-UiO-66 and Mi-UiO-67) fluorescent probes for the detection of Cys and GSH. They showed high sensitivity (10(-11) M) and selectivity for Cys and GSH, and their fluorescence imaging of Cys and GSH in living cells was well demonstrated.

A nanoporous Ag(I)-MOF showing unique selective adsorption of benzene among its organic analogues.

A stable porous Ag(I)-MOF with new topology is constructed from AgSbF6 and 3,6-bis[2-(4-oxide-quinoxaline)-yl]-4,5-diaza-3,5-octadiene (L). This compound can be a highly selective porous MOF material to effectively separate benzene from its six-membered cyclic organic analogues such as cyclohexane, cyclohexene and o-, m-, p-xylene under ambient conditions in both vapor and liquid phases.

Cu(I)-MOF: naked-eye colorimetric sensor for humidity and formaldehyde in single-crystal-to-single-crystal fashion.

A porous Cu(I)-MOF was constructed from CuI and 1-benzimidazolyl-3,5-bis(4-pyridyl)benzene. This Cu(I)-MOF can be a highly sensitive naked-eye colorimetric sensor to successively detect water and formaldehyde species in a single-crystal-to-single-crystal fashion. Solid-state guest-responsive luminescence is also used to monitor the sensing process.

The structures of three Hg2X4L2 macrocycles {X = Cl, Br and I, and L = 1,2-bis[4-(pyridin-3-yl)phenoxy]ethane} assembled from ether-bridged dipyridyl ligands.

The new ether-bridged dipyridyl ligand 1,2-bis[4-(pyridin-3-yl)phenoxy]ethane (L) has been used to synthesize three isostructural centrosymmetric binuclear Hg(II) macrocycles, namely bis{µ-1,2-bis[4-(pyridin-3-yl)phenoxy]ethane-κ(2)N:N'}bis[dichloridomercury(II)], [Hg(2)Cl(4)(C(24)H(20)N(2)O(2))(2)], and the bromido, [Hg(2)Br(4)(C(24)H(20)N(2)O(2))(2)], and iodido, [Hg(2)I(4)(C(24)H(20)N(2)O(2))(2)], analogues. The Hg atoms adopt a highly distorted tetrahedral coordination environment consisting of two halides and two pyridine N-donor atoms from two bridging ligands. In the solid state, the macrocycles form two-dimensional sheets in the bc plane through noncovalent Hg...X and X...X (X = Cl, Br and I) interactions.

[Epidemiological survey of a captive Chinese rhesus macaque breeding colony in Yunnan for SRV, STLV and BV].

Nonhuman primates are critical resources for biomedical research. Rhesus macaque is a popularly used laboratory nonhuman primate that share many characteristics with humans. However, rhesus macaques are the natural host of two exogenous retroviruses, SRV (simian type D retrovirus) and STLV (simian T lymphotropic virus). SRV and STLV may introduce potentially significant confounding factors into the study of AIDS model. Moreover, B virus (ceropithecine herpesvirus 1) is likely to harm not only rhesus macaque but also humans in experiments involving rhesus macaque. Yunnan province has large-scale breeding colonies of Chinese rhesus macaque. Therefore there is an urgent need for SPF Chinese rhesus macaque colonies. Here we investigated SRV, STLV and BV infections in 411 Chinese rhesus macaque by PCR technique. The results showed that the prevalence of SRV, STLV and BV among Chinese rhesus macaque breeding colony was 19.71% (81/411), 13.38% (55/411) and 23.11% (95/411), respectively. Comparison of viruses infection in different age-groups and male/female of Chinese rhesus macaque was also analyzed. This study will contribute to establishment of SPF Chinese rhesus macaque breeding colony.

[Study on chemical constituents from petroleum ether-soluble parts of cones of Platycladus orientalis].

OBJECTIVE: To study chemical constituents from petroleum ether-soluble parts of cones of Platycladus orientalis. METHODS: The compound were isolaeed by repeated column chromatography of silica gel and Sephadex LH-20. The structures were elucidated by physicochemical properties and spectrum analysis. RESULTS: Seven constituents were isolated and identified as sandaracopimaric acid (1), 6alpha-hydroxy sandaracopimaric acid (2), ent-isopimara-8 (14), 15-dien-3beta, 19-diol (3), ent-isopimara-8 (9), 15-dien-3beta-ol (4), ent-isopimara-8 (14),15- dien-3beta-ol (5), isocupressic acid (6) and 15-acetylisocupressic acid (7). CONCLUSION: Compounds 2 and 7 are isolated from this genus for the first time.

Highly efficient iodine species enriching and guest-driven tunable luminescent properties based on a cadmium(II)-triazole MOF.

The first example of highly efficient iodine enrichment based on a Cd(II)-triazole MOF (1) via both molecular sorption and ion-exchange approaches is reported.

Two threefold interpenetrated two-dimensional frameworks based on a flexible imidazole-containing ligand and benzene-1,4-dicarboxylate.

The open-chain polyether-bridged flexible ligand 1,2-bis[2-(1H-1,3-imidazol-1-ylmethyl)phenoxy]ethane (L) has been used to create two two-dimensional coordination polymers under hydrothermal reaction of L with Cd(II) or Co(II), in the presence of benzene-1,4-dicarboxylic acid (H(2)bdc). In poly[[(µ(2)-benzene-1,4-dicarboxylato){µ-1,2-bis[2-(1H-1,3-imidazol-1-ylmethyl)phenoxy]ethane}cadmium(II)] dihydrate], {[Cd(C(8)H(4)O(4))(C(22)H(22)N(4)O(2))]·2H(2)O}(n), (I), and the cobalt(II) analogue {[Co(C(8)H(4)O(4))(C(22)H(22)N(4)O(2))]·2H(2)O}(n), (II), the Cd(II) and Co(II) cations are six-coordinated by four carboxylate O atoms from two different bdc(2-) dianions in a chelating mode and two N atoms from two distinct L ligands. The metal ions, bdc(2-) dianions and L ligands each sit across crystallographic twofold axes. The bdc(2-) coordination mode and the coordinating orientation of the L ligand play an important role in constructing the novel two-dimensional framework. Complexes (I) and (II) are threefold interpenetrated two-dimensional frameworks; their structures are almost isomorphous, while the bond lengths, angles and hydrogen bonds are different in (I) and (II).

[Sero-epidemiology of six viruses natural infection in Tupaia belangeri chinensis].

Tupaia (Tupaia belangeris chinensis, tree shrew) as a new experiment animal in medicine are non-rodent, small animals and close to primates in evolution. Experimental animals infected with viruses will affect the animal's health, interference experiment, and even endanger the operator's safety. Therefore, the viral infection in experimental animals has long been considered an important part of quality control. Lack of clearer viral natural infection information on the T. belangeris limits its use. Six viruses infection in 272 wild capture and artificial breeding Tupaia were investigated in this study. All serum samples were detected for the hepatitis B virus surface antigen, the total antibodies of HCV, hepatitis E virus (HEV), adenovirus (ADV), herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2) by ELISA. The results showed that anti-HCV antibody and anti-HEV, ADV, HSV-1 IgG antibodies were negative, only one sample was positive of anti-HSV-2 IgG.. Three samples were positive in the primary ELISA detection of HBV surface antigen, but two pairs of semi-quantitative detection of hepatitis B and further recognized as negative. The results implied that antigen or antibody-positive results appeared in the hepatitis serological test is not accurate enough and confirmation by other virological indicators is necessary. Tupaia breeding herd should be screened for HSV-2 in order to prevent and control the virus infection.

New isoprenylated flavonoids and cytotoxic constituents from Artocarpus tonkinensis.

Two new isoprenylated flavonoids, artotonins A and B (1 and 2), along with 13 known compounds (3-15), were isolated from the roots of Artocarpus tonkinensis A. Chev. ex Gagnep. The structures were elucidated by spectroscopic methods. Cyclocommunol (6), isocyclomulberrin (7), cudraflavone C (11), and morusin (13) exhibited cytotoxicity against hepatocellular carcinoma (SMMC-7721) and gastric carcinoma (BGC-823 and SGC-7901) cell lines.