Search

Six new seco-cytochalasins A-F (1-6), two new asperlactones G-H (7-8) along with three known cytochalasins (9-11) were isolated from the solid cultures of an endophytic fungus Aspergillus sp. Their structures were elucidated by comprehensive spectral analysis, and their absolute configurations were determined through Mo 2 (OCOCH 3 ) 4 -induced electronic circular dichroism (ECD) spectra and Rh 2 (OCOCF 3 ) 4 -induced ECD experiment. Compounds 5 and 6 were rare seco-cytochalasins possessing an α, β-unsaturated furanone structure in their side-chains. These isolates exhibited cytotoxicity against human lung cancer A-549 cell line with IC 50 values ranging from 7.8 to 70.2 μM. At the concentration of 16 μM, compound 4 also exerted a 3-fold enhancement of doxorubicin susceptibility on doxorubicin-resistant human breast cancer (MCF-7/DOX) cell line., (Copyright © 2018 Elsevier B.V. All rights reserved.)

β-Thalassemia (β-thal) is one of the most common inherited disorders in southern China. More than 300 β-globin gene mutations around the world have been reported in the HbVar database. In this study, a novel mutation in a 30-year-old Chinese woman [IVS-II-203-205 (TCT>CC), HBB: c.315+203TCT>CC] was first found by direct sequencing. Subsequently, investigation of her parents' genetic codes was completed, and the results showed that her father also carried this mutation. Based on the features observed in clinical practice, this novel mutation was regarded as a mild phenotype of β-thal.

The phase transformation kinetic process of amphiphilic copolymer polyoxyethylene/polyoxypropylene/polyoxyethylene[PEO-PPO-PEO(F127)] blending polyvinylidene fluoride (PVDF) casting solution in an aqueous gel bath was investigated. The influences of F127 content on the PEO enrichment rate of PVDF membrane surface, membrane morphology and structural parameters were investigated by a total reflection fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscope (SEM), atomic force microscopy (AFM) and other analytical techniques. F127/PVDF blending membrane fouling behavior of bovine serum albumin (BSA) was evaluated by the static adsorption capacity, normalized filtration decay rate and membrane fouling resistance model. The results showed that the membrane delayed phase separation process increased, the membrane surface, internal pore size and porosity increased and the surface roughness increased with increasing F127 addition, and the increment of PEO enrichment rate on the membrane surface became stable when the F127 content reached 15%. F127 blending membranes with F127 contents ranging from 15% to 25% had a higher flux and BSA rejection, lower static adsorption capacity, slower flux decay rate, lower irreversible fouling index and smaller pore blocking resistance and cake layer resistance distribution coefficient, which showed a good anti-fouling property.

With an aim at detecting the ultra-low concentration of avian influenza virus (AIV), a highly sensitive hybrid assay based on immunology and polymerase chain reaction was developed. The TopYield microtiter plates were coated with ten-fold serial dilutions of H5N1 subtype AIV ranging from 10 EID(50 )ml(-1)~10(-4) EID(50) ml(-1),which was recognized by mouse anti-AIV H5 monoclonal antibody (MAb) that was directly linked with reporter DNA using a heterobifunctional cross-linker. After extensive washing, the reporter DNA including a BamH I-restriction site was released by a specific enzymatic restriction, then transferred to PCR tubes, amplified, and used as the signal for detection of AIV. Under the optimized condition, MAb-based immuno-PCR (IPCR) method could measure 100 µl of AIV H5N1 with 10(-4 )EID(50) ml(-1).To evaluate the sensitivity of IPCR, the same concentration and volume of AIV H5N1 were detected by conventional RT-PCR and sandwich ELISA. The results showed that IPCR had an approximately 1,000-fold improvement over the conventional ELISA, and a 100-fold enhancement compared with RT-PCR in detection sensitivity. To further evaluate the specificity of IPCR for AIV H5 subtype, the tracheal swab specimens, taken from chickens which were infected with H9N2, and the allantoic fluid from eggs inoculated by AIV H3N2, H7N1, H9N2, were detected by IPCR. To mimic clinical samples, pharyngeal-tracheal swab specimens were collected from healthy chickens and spiked with H5N1, H5N2, H5N3 for analysis by immuno-PCR. The results demonstrated that IPCR was a highly sensitive and specific assay for AIV H5, and could be applied to clinical detection for low amount of AIV H5 subtype. This MAb-based immuno-PCR method provided a platform capable of mass screening of clinical samples for AIV H5 subtype and could serve as a model for other immuno-PCR assays.

An ion chromatography method with non-suppressed conductivity detection was developed for the simultaneous determination of dimethylamine (DMA), trimethylamine (TMA) and trimethylamine-n-oxide (TMAO) in aquatic products. They were separated by means of cation-exchange chromatography using a 3.0 mmol/L methanesulfonic acid solution as eluent and an IonPac CS17 column (250 mm x 4 mm i.d.) as the separation column. Detection limits of dimethylamine, trimethylamine and trimethylamine-n-oxide were 0.06, 0.08 and 0.10 mg/L, respectively. The relative standard deviations (RSDs) of peak area were less than 3.53%. The recoveries were between 93.7% and 104.1%. Unlike traditional methods, this validated method is inexpensive and stable.

This communication reports the first example of cyclic ferric clusters with an odd number of iron atoms capped by phosphonate ligands, namely, [Fe9(mu-OH)(7)(mu-O)2(O3PC6H9)8(py)12]. The magnetic studies support a S = 1/2 ground state with an exchange coupling constant of about J approximately equal to -30 K.

Treatments of Mn(O(2)CR)(2) (R = Me, Ph) with NBu(4)MnO(4) in CH(3)CN or CH(3)CN/CH(2)Cl(2) in the presence of acetic acid, delta(1)-cyclohexenephosphonic acid (C(6)H(9)PO(3)H(2)), and 2,2'-bipyridine or 1,10-phenanthroline result in three novel dodecamanganese(III) clusters [Mn(12)O(8)(O(2)CMe)(6)(O(3)PC(6)H(9))(7)(bipy)(3)] (1), [Mn(12)O(8)(O(2)CPh)(6)(O(3)PC(6)H(9))(7)(bipy)(3)] (2), and [Mn(12)O(8)(O(2)CPh)(6)(O(3)PC(6)H(9))(7)(phen)(3)] (3). They have a similar Mn(12) core of [Mn(III)(12)(mu(4)-O)(3)(mu(3)-O)(5)(mu-O(3)P)(3)] with a new type of topologic structure. Solid-state dc magnetic susceptibility measurements of complexes 1-3 reveal that dominant antiferromagnetic interactions are propagated between the magnetic centers. The ac magnetic measurements suggest an S = 2 ground state for compounds 1 and 3 and an S = 3 ground state for compound 2.

This paper reports the syntheses and characterization of four isomorphous compounds (NH(3)C(6)H(4)NH(3))M(2)(hedpH)(2).H(2)O [M = Fe (1), Co (2), Mn (3), Zn (4); hedp = C(CH(3))(OH)(PO(3))(2)]. Each contains two crystallographically different kinds of {M(2)(hedpH)(2)}(n) double chains, where the {M(2)(mu-O)(2)} dimer units are connected by O-P-O bridges. The double chains are connected through extensive hydrogen bonds, hence generating a three-dimensional supramolecular network. The temperature-dependent magnetic susceptibility measurements show dominant antiferromagnetic interactions in compounds 1-3, mediated through the mu-O and/or O-P-O bridges between the metal(II) centers. The magnetization measurements reveal that compounds 1-3 experience field-induced magnetic transitions at low temperatures.

This paper reports two new cobalt phosphonate compounds [NH3(CH2)nNH3]Co2(hedpH)2.2H2O [n = 4 (1), 5 (2)], where hedp is (1-hydroxyethylidene)diphosphonate [CH3C(OH)(PO3)2]. Both contain ladderlike chains with the same composition [Co2(hedpH)2](n)(2n-), where edge-shared [CoO6] octahedra are each bridged by O-P-O units. The chains are linked by very strong hydrogen bonds to form a three-dimensional open network with channels in which the diammonium counterions and lattice water reside. Magnetic studies reveal dominant antiferromagnetic interactions between the Co centers within the chain in both compounds. The field dependent magnetization confirms the occurrence of the field-induced magnetic transitions, with the critical fields ca. 25 kOe for 1 and 27.5 kOe for 2, respectively. In the case of compound 2, weak ferromagnetism is also observed at very low temperatures, possibly arising from spin canting of the antiferromagnetically coupled Co(II) ions in the chain. Crystal data: 1, monoclinic, P2(1)/c, a = 5.4868(8), b = 12.9116(18), and c = 15.251(2) A, beta = 98.843(2) degrees, V = 1067.6(3) A(3), Z = 2; 2, monoclinic, P2(1)/c, a = 5.4757(7), b = 12.7740(16), and c = 15.794(2) A, beta = 98.797(2) degrees, V = 1091.7(2) A(3), Z = 2.

The title compound, [Ag(3)WIS(4)(C(17)H(14)NP)(3)].0.5CH(2)Cl(2), is a cubane-type heterometallic cluster containing diphenyl(2-pyridyl)phosphine (Ph(2)PPy). The pyridyl group of Ph(2)PPy remains uncoordinated, so the Ph(2)PPy ligand is monodentate and coordinates to one Ag atom. The W atom and three Ag atoms form a distorted tetrahedral geometry, capped by one I atom and three S atoms.

In the title compound, [1,4-bis(diphenylphosphino)butane-2kappa(2)P,P']di-mu-thio-1:2kappa(4)S-dithio-1kappa(2)S-palladium(II)tungsten(VI) N,N'-dimethylformamide hemisolvate hemihydrate, [PdWS(4)(C(28)H(28)P(2))].0.5C(3)H(7)NO.0.5H(2)O, the Pd atom is coordinated by two S atoms from the distorted-tetrahedral [WS(4)](2-) anion and two P atoms from the dppb molecule [dppb is 1,4-bis(diphenylphosphino)butane] in an approximately square-planar configuration. A puckered seven-membered ring is formed by the Pd atom and the dppb ligand.

Compound Na6Co7(hedp)2(hedpH)4(H2O)4 x 8H2O (hedp = 1-hydroxyethylidenediphosphonate) with a novel layer structure is reported in this paper. The layer maybe viewed as made up from two types of chains each of composition Co3(hedp)2 and Co2(hedpH)2. Magnetic measurements at 1.8 K reveal a metamagnetic transition at ca. 6.5 kOe, followed by a second transition to a ferromagnetic state at ca. 30 kOe.

This paper reports the synthesis and crystal structure of a novel mixed valence copper(I,II) compound, Cu(I)(2)Cu(II)(hedpH(2))(2)(4,4'-bpy)(2).2H(2)O (1), where hedp represents 1-hydroxyethylidenediphosphonate. The structure is composed of [Cu(I)(2)Cu(II)(hedpH(2))(2)] trimer units and 4,4'-bipyridine linkages, forming a two-dimensional brick-wall-like layer structure in the ab plane. The layers are stacked along the [001] direction with strong interlayer hydrogen bonds and pi-pi interactions, thus leading to the construction of a three-dimensional network.

A novel, three-dimensional copper diphosphonate Cu4(CH3C(OH)(PO3)2)2(C4H4N2)(H2O)4 (1) incorporating an organic pyrazine ligand has been hydrothermally synthesized, which exhibits antiferromagnetic ordering below 4.2 K and metamagnetic behavior.

Four new zinc diphosphonate compounds with formulas [NH(3)(CH(2))(2)NH(3)]Zn(hedpH(2))(2).2H(2)O, 1, [NH(3)(CH(2))(n)()NH(3)]Zn(2)(hedpH)(2).2H(2)O, (n = 4, 2; n = 5, 3; n = 6, 4) (hedp = 1-hydroxyethylidenediphosphonate) have been synthesized under hydrothermal conditions at 110 degrees C and in the presence of alkylenediamines NH(2)(CH(2))(n)()NH(2) (n = 2, 4, 5, 6). Crystallographic data for 1: monoclinic, space group C2/c, a = 24.7422(15), b = 5.2889(2), c = 16.0338(2) A, beta = 117.903(1) degrees, V = 1856.17(18) A(3), Z = 4; 2: monoclinic, space group P2(1)/n, a = 5.4970(3), b = 12.1041(6), c = 16.2814(12) A, beta = 98.619(5) degrees, V = 1071.07(11) A(3), Z = 2; 3: monoclinic, space group P2(1)/n, a = 5.5251(2), b = 12.5968(3), c = 16.1705(5) A, beta = 99.182(1) degrees, V = 1111.02(6) A(3), Z = 2; 4: triclinic, space group P-1, a = 5.4785(2), b = 14.1940(5), c = 16.0682(6) A, alpha = 81.982(2) degrees, beta = 89.435(2) degrees, gamma = 79.679(2) degrees, V = 1217.11(8) A(3), Z = 2. In compound 1, two of the phosphonate oxygens are protonated. The metal ions are bridged by the hedpH(2)(2-) groups through three of the remaining four phosphonate oxygens, forming a one-dimensional infinite chain. The protonated ethylenediamines locate between the chains in the lattice. In compounds 2-4, only one phosphonate oxygen is protonated. Compounds 2 and 3 have a similar three-dimensional open-network structure composed of [Zn(2)(hedpH)(2)](n) double chains with strong hydrogen bonding interactions between them, thus generating channels along the [100] direction. The protonated diamines and water molecules reside in the channels. Compound 4 contains two types of [Zn(2)(hedpH)(2)](n) double chains which are held together by strong hydrogen bonds, forming a two-dimensional network. The interlayer spaces are occupied by the [NH(3)(CH(2))(6)NH(3)](2+) cations and water molecules. The significant difference between structures 2-4 is also featured by the coordination geometries of the zinc atoms. The geometries of those in 2 can be described as distorted octahedral, and those in 3 as distorted square pyramidal. In 4, two independent zinc atoms are found, each with a distorted octahedral and a tetrahedral geometry, respectively.

In the title coordination polymer, [Pb(NCS)(2)(C(12)H(12)N(2))], the coordination geometry about the Pb(II) atom is a distorted octahedron, composed of two N atoms from bpe ligands [bpe is 1,2-bis(4-pyridyl)ethane], two other N atoms from NCS(-) groups and two neighbouring S atoms through short contacts. The trans-bpe ligands act as bridges between two Pb(II) centres resulting in the formation of a linear chain. The terminal S atoms of the NCS(-) ligands make short contacts with the Pb(II) atom of neighbouring chains to form an infinite two-dimensional polymeric structure.

[PPh4]2[WSe4] reacts with an equivalent of [Ag(MeCN)4][ClO4] in DMF to afford a linear polymeric cluster [[Ph4P][(mu-WSe4)Ag]]n (1). Treatment of cluster 1 with excess La(NO3)3.3H2O in Me2SO solution resulted in the formation of a helical chain polymeric cluster [[La(Me2SO)8][(mu-WSe4)3Ag3]]n (2). Cluster 2 crystallizes in the monoclinic space group P2(1/n) with four formula units in a cell of dimensions a = 12.7642(5) A, b = 24.1725(9) A, c = 19.4012(7) A, and beta = 103.546(11) degrees. Refinement by full-matrix least-squares techniques gave final residuals R = 0.0540 and Rw = 0.1116 for 494 variables and 7593 reflections (Fo(2) > 2.0sigma(Fo(2))). The anion [[(mu-WSe4)3Ag3]]n(3n-) in 2 can be described as a butterfly-type SeWSe3Ag2 basic repeating unit linked through interactions with a Ag atom of one fragment and a Ag atom of another to form an intriguing helical array. The CuCN, KCN, and [Et4N]2[WSe4] reaction system resulted in the formation of a novel three-dimensional cluster [[Et4N]2[(mu4-WSe4)Cu4(CN)4]]n (4) either in DMF/2-picoline or in solid at 80 degrees C. Cluster 4 crystallizes in the orthorhombic space group Fddd with cell constants a = 11.090(2) A, b = 23.206(5) A, c = 23.910(5) A, and Z = 8. Anisotropic refinement with 1510 reflections (Fo(2) > 2.0sigma(Fo(2))) and 82 parameters for all non-hydrogen atoms yielded the values of R = 0.0428 and Rw = 0.0887. The anion structure of 4 is built up from a WSe4Cu4 unit bridged by cyanide ligands to form a three-dimensional cross framework. The air- and moisture-stable polymeric clusters easily decompose into small molecular clusters when treated with ligands such as PPh3 and pyridine (Py). Cluster 2 exhibits both strong optical absorption and an optical self-focusing effect (effective alpha2 = 2.2 x 10(-9) m2.W(-1), n2 = 6.8 x 10(-15) m2.W(-1); examined in a 0.13 mM DMF solution). Cluster 4 shows good photostability in the process of measurement and a large optical limiting effect (the limiting threshold is ca. 0.2 J.cm(-2)).

Three new copper(II) diphosphonates, (NH(4))(2)Cu(3)(hedp)(2)(H(2)O)(4) (1), [NH(3)(CH(2))(4)NH(3)]Cu(3)(hedp)(2).2H(2)O (2), and [NH(2)(C(2)H(4))(2)NH(2)]Cu(3)(hedp)(2) (3), where hedp = 1-hydroxyethylidenediphosphonate, have been synthesized and characterized by single-crystal structural analysis. Crystal data: 1, monoclinic, P2(1)/n, a = 6.2137(13) Å, b = 14.747(2) Å, c = 11.1802(12) Å, beta = 105.83(2) degrees, Z = 2; 2, triclinic, P&onemacr;, a = 7.4840(12) Å, b = 8.032(3) Å, c = 10.007(2) Å, alpha = 111.68(2) degrees, beta = 96.188(14) degrees, gamma = 96.97(2) degrees, Z = 1; 3, triclinic, P&onemacr;, a = 7.0155(6) Å, b = 8.0904(9) Å, c = 9.2644(11) Å, alpha = 112.611(13) degrees, beta = 90.819(8) degrees, gamma = 92.824(7) degrees, Z = 1. The compound 1 is composed of infinite chains with a ladder-type motif. The compounds 2 and 3 adopt a two-dimensional layer structure which contains four- and eight-membered rings assembled from vertex-sharing {CuO(4)} units and {CPO(3)} tetrahedra. The magnetic properties of 3 have been investigated.

In functional units d and g from the betaC-haemocyanin of the gastropod Helix pomatia, aminoacid analysis in the presence of dimethyl sulfoxide showed the occurrence of seven cysteine residues. Titration with 5,5'-dithiobis(2-nitrobenzoic acid), however, did not reveal any free thiol group. Pepsinolysis at pH 2.0 followed by amino acid analysis and partial sequencing of the cysteine-containing peptides showed that six cysteine residues are involved in the formation of three disulfide bridges at corresponding positions. The results indicated that the remaining cysteine residue is linked by a thioether bridge to a histidine residue located two positions further in the sequence (H. pomatia d Cys60 His62; H. pomatia g Cys66 His68). This residue corresponds to one of the three histidine residues considered to be involved in the coordination of the copper A atom of the dinuclear copper group of the functional units. The presence of the thioether bond was further evidenced by an absorption band at 255 nm and by molecular mass determinations with electrospray mass spectrometry on a peptic peptide from H. pomatia d and on peptides obtained by proteolysis of carboxymethylated H. pomatia d with trypsin and pronase. Upon sequence analysis the cysteine-histidine thioether bridge was cleaved into didehydroalanine (polymers) and 2-thiolhistidine. A peptide with a cysteine-histidine thioether bridge was isolated from pepsinolysates of functional units c, e, f, g and h of Sepia officinalis and unit g of Octopus vulgaris, obtained from haemocyanin of the cephalopods S. officinalis and O. vulgaris. A cysteine-histidine thioether bridge, which was reported previously for tyrosinase of Neurospora crassa, thus seems to be a general feature for functional units of molluscan haemocyanins.

A newly developed rat long-term bone marrow culture system was used to study the role of Pan/E2A basic helix-loop-helix transcription factors during B-cell development. In this system, B-lymphocyte progenitors actively differentiate into mature B cells. Monoclonal (Yae) and polyclonal (anti-Pan) antibodies were employed to characterize the expression of Pan proteins by Western blot assay during hematopoiesis and to examine the components of immunoglobulin heavy-chain gene enhancer element-binding species by electrophoretic mobility shift assay. During B-cell development, the appearance of Pan/E2A proteins preceded the expression of immunoglobulin heavy-chain protein. A Pan-containing immunoglobulin heavy-chain enhancer element (mu E5)-binding species (BCF1), composed of immunoreactive Pan-1/E47 but not Pan-2/E12, was observed concomitantly with the detection of Pan/E2A proteins. In addition to BCF1, other mu E5-binding species were detected which were not recognized by the Yae antibody. Two of these species were present in primary B-lymphocyte and myeloid cultures and were recognized by an anti-upstream stimulatory factor antiserum. Although Pan/E2A proteins have been proposed to be ubiquitous, Pan/E2A proteins were not detected in primary myeloid cultures composed mainly of granulocytes and macrophages or in the macrophage cell line J774. The absence of Pan/E2A proteins in differentiated myeloid cells correlated with low steady-state levels of Pan/E2A RNA. However, Pan/E2A proteins were present in a promyeloid cell line, 32DCL3, suggesting that extinction of Pan/E2A expression may play a role in myelopoiesis.

The helix-loop-helix (HLH) transcription factors, Pan-1 (E47) and Pan-2 (E12), are produced by the mechanism of alternative transcript splicing. Pan-1 and Pan-2 were expressed in Escherichia coli, and a purification scheme was developed. Purified Pan-2 was used to immunize Smith-Webster mice and a hybridoma was generated that produced a monoclonal antibody (Yae) that specifically recognized both native and denatured Pan-1 and Pan-2. Deletion mapping and sequence transfer studies have localized the determinant recognized by the Yae antibody to the region 195-208 of Pan-2. This region is conserved in Pan-1 and Pan-2. The Yae antibody recognized in vitro-synthesized ITF-1, a third E2A (Pan) gene product also produced by the mechanism of alternative RNA splicing, but did not recognize the related HLH proteins, ITF-2, REB alpha, or REB beta. By Western blot assay of pancreatic acinar cells, the Yae antibody detected a single protein species of 72 kD that comigrated with in vitro-synthesized Pan-1 and Pan-2.

The DNA-binding factors encoded by the E2A gene, which include the basic helix-loop-helix proteins E12 and E47, are thought to regulate Ig gene expression. In the rat these factors are products of the Pan locus and are referred to as Pan-2 and Pan-1, respectively. To determine when during B cell differentiation Pan (E2A) DNA-binding proteins are first expressed, cells from a newly developed rat long term lymphoid bone marrow culture system were analyzed molecularly and phenotypically using a newly defined anti-Pan mAb. The data indicate that Pan-expressing cells appear in B cell progenitors before the appearance of the CD45R B lineage-associated Ag or microH chain protein. The results also indicate that Pan proteins are present in cells that had undergone D-JH rearrangements. Finally, although Pan (E2A) proteins are present in myeloid precursors, expression is extinguished as differentiation into mature myeloid cells occurs.

Cathepsins S and H were purified from bovine spleen and their catalytic properties compared. The enzymes were shown to be similar by chromatographic properties and by the ability to hydrolyze Bz-Phe-Val-Arg-NHMec. They could however be distinguished by the fact that cathepsin S reacted with Z-[125I]Tyr-Ala-CHN2 and hydrolyzed Z-Phe-Arg-NHMec whereas cathepsin H did not. The substrate and inhibitor specificities of cathepsin H suggest that unlike cathepsins B, L, and S, it cannot accommodate peptides with aromatic side chains in P2. Cathepsins L and S can accommodate the aromatic side chain of tyrosine in P1 readily, whereas cathepsins H and B cannot. The specificities of each enzyme for synthetic substrates and inhibitors have enabled the construction of models of the architecture of the active sites of the mammalian cysteine proteinases which clearly show the differences between the four enzymes. A significant characteristic of cathepsin S is that it can hydrolyze insoluble elastin at both acidic and neutral pH; this distinguishes it from all of the other lysosomal proteinases.