Showing papers by "Hong Liu published in 2007"
269 citations
TL;DR: A two-dimensional resolution system of channels and substrate zones was proposed for multiplex immunoassay performed with a designed multichannel chemiluminescent (CL) detection device coupled with a single photomultiplier, showing acceptable detection and fabrication reproducibility.
Abstract: A two-dimensional resolution system of channels and substrate zones was proposed for multiplex immunoassay performed with a designed multichannel chemiluminescent (CL) detection device coupled with a single photomultiplier. Using carcinoma antigen 125 (CA 125), carcinoma antigen 153 (CA 153), carcinoma antigen 199 (CA 199), and carcinoembryonic antigen (CEA) as two couples of model analytes, two couples of capture antibodies were immobilized in two channels, respectively. With a sandwich format, the CL substrates for alkaline phosphatase and horseradish peroxidase were delivered into the channels sequentially to perform a multiplex immunoassay after the sample and tracer antibodies were introduced into the channels for on-line incubation. CA 125, CA 153, CA 199, and CEA could be assayed in the ranges of 0.50−80, 2.0−100, and 5.0−150 U/mL and 1.0−70 ng/mL with limits of detection of 0.15, 0.80, and 2.0 U/mL and 0.65 ng/mL at 3σ, respectively. The whole assay process including regeneration of the device cou...
91 citations
TL;DR: The in vivo antitumor studies and pharmacokinetics of compound 6l showed that it might be a promising new hit for further development of antitumorectal cancer agents.
70 citations
TL;DR: The epothilones are highly promising prospective anticancer agents that are produced by the myxobacterium Sorangium cellulosum and a simple microtiter method for primary screening was developed and the production was greatly increased by the genome shuffling.
Abstract: The epothilones are highly promising prospective anticancer agents that are produced by the myxobacterium Sorangium cellulosum. We mutated the epothilone producing S. cellulosum strain So0157-2 to improve the production of epothilones. For evaluation in high-throughput of a large number of mutants, we developed a simple microtiter method for primary screening. Using the classical UV-mutation method plus selection pressures, the production capacity was increased about 0.5∼2.5 times the starting strain. The mutants with higher production and different phenotypes were further subjected to recursive protoplast fusions and the fusants products were screened under multi-selection pressure. Furthermore, the production was greatly increased by the genome shuffling. For epothilone B, the production of one fusant was increased about 130 times compared to the starting strain, increasing from 0.8 mg l−1 to 104 mg l−1.
63 citations
TL;DR: In this paper, a co-precipitation method was used to produce transparent yttrium aluminum garnet (YAG) nano-crystallites by using ammonium hydrogen carbonate as precipitant.
58 citations
TL;DR: It is suggested that channel 1 can be used for metyrapone egress, whereas both channel 2 and channel 3 have a low probability of serving as an exit channel for metYrapone.
Abstract: To identify a possible pathway(s) for metyrapone egress from the active site of P450 3A4, a 5-ns conventional molecular dynamics simulation followed by steered molecular dynamics simulations was performed on the complex with metyrapone. The steered molecular dynamics simulations showed that metyrapone egress via channel 1, threading through the B-C loop, only required a relatively small rupture force and small displacement of residues, whereas egress via the third channel, between helix I and helices F′ and G′, required a relatively large force and perturbation of helices I, B′, and C. The conventional dynamics simulation indicated that channel 2, located between the β1 sheet, B-B′ loop, and F′-G′ region, is closed because of the movement of residues in the mouth of this channel. The findings suggest that channel 1 can be used for metyrapone egress, whereas both channel 2 and channel 3 have a low probability of serving as an exit channel for metyrapone. In addition, residues F108 and I120 appear to act as two gatekeepers to prevent the inhibitor from leaving the active site. These results are in agreement with previous site-directed mutagenesis experiments.
51 citations
TL;DR: Alcaligenes sp.
Abstract: Alcaligenes sp. strain NyZ215 was isolated for its ability to grow on ortho-nitrophenol (ONP) as the sole source of carbon, nitrogen, and energy and was shown to degrade ONP via a catechol ortho-cleavage pathway. A 10,152-bp DNA fragment extending from a conserved region of the catechol 1,2-dioxygenase gene was obtained by genome walking. Of seven complete open reading frames deduced from this fragment, three (onpABC) have been shown to encode the enzymes involved in the initial reactions of ONP catabolism in this strain. OnpA, which shares 26% identity with salicylate 1-monooxygenase of Pseudomonas stutzeri AN10, is an ONP 2-monooxygenase (EC 1.14.13.31) which converts ONP to catechol in the presence of NADPH, with concomitant nitrite release. OnpC is a catechol 1,2-dioxygenase catalyzing the oxidation of catechol to cis,cis-muconic acid. OnpB exhibits 54% identity with the reductase subunit of vanillate O-demethylase in Pseudomonas fluorescens BF13. OnpAB (but not OnpA alone) conferred on the catechol utilizer Pseudomonas putida PaW340 the ability to grow on ONP. This suggests that OnpB may also be involved in ONP degradation in vivo as an o-benzoquinone reductase converting o-benzoquinone to catechol. This is analogous to the reduction of tetrachlorobenzoquinone to tetrachlorohydroquinone by a tetrachlorobenzoquinone reductase (PcpD, 38% identity with OnpB) in the pentachlorophenol degrader Sphingobium chlorophenolicum ATCC 39723.
45 citations
TL;DR: It is demonstrated that structure-based computer screening strategy could be used to identify novel, structurally diverse compounds targeting the pore binding pocket of the outer mouth of voltage-gated K+ channels.
Abstract: Potassium ion (K+) channels are attractive targets for drug discovery because of the essential roles played in biological systems. However, high-throughput screening (HTS) cannot be used to screen K+ channel blockers. To overcome this disadvantage of HTS, we have developed a virtual screening approach for discovering novel blockers of K+ channels. On the basis of a three-dimensional model of the eukaryotic K+ channels, molecular docking-based virtual screening was employed to search the chemical database MDL Available Chemicals Directory (ACD). Compounds were ranked according to their relative binding energy, favorable shape complementarity, and potential to form hydrogen bonds with the outer mouth of the K+ channel model. Twenty candidate compounds selected from the virtual screening were examined using the whole-cell voltage-clamp recording in rat dissociated hippocampal neurons. Among them, six compounds (5, 6, 8, 18−20) potently blocked both the delayed rectifier (IK) and fast transient K+ currents (I...
35 citations
TL;DR: A series of novel indole derivatives was designed, synthesized and evaluated by cell-based assays for their inhibitory activities against 5-LOX in rat peritoneal leukocytes, showing excellent in vitro activities and may possess potential for the treatment of LT-related diseases.
33 citations
31 citations
TL;DR: Overall, the re-engineered P450 2B11dH enzymes exhibited enhanced catalytic efficiency with several substrates including the anti-cancer prodrugs.
TL;DR: The results presented in this paper suggest that the inherent genetic strategies, together with frequent gene importing from many organisms (HGT) have contributed to the evolution of modular PKSs in Sorangium.
TL;DR: A one-pot, large-scale procedure for preparing the Belokon-Soloshonok nucleophilic glycine equivalent 2-[N-(alpha-picolyl)amino]benzophenone (PABP) derived Ni(II) complex [GlyNi( II)PABP] is described.
Abstract: A one-pot, large-scale procedure for preparing the Belokon-Soloshonok nucleophilic glycine equivalent 2-[N-(alpha-picolyl)amino]benzophenone (PABP) derived Ni(II) complex [GlyNi(II)PABP] is described. It has been accomplished by using isobutyl chloroformate to form PABP and then NaH/KOH as mixed bases to afford the corresponding complexes in a one-pot manner (up to an overall yield of 98%). The potential of this method for preparation of beta-amino acids derivatives, such as beta-AlaNi(II)PABP and beta-PheNi(II)PABP, has been demonstrated. The structure of beta-AlaNi(II)PABP is characterized by single-crystal X-ray diffraction.
TL;DR: A series of novel benzamide derivatives was designed, synthesized, and their inhibitory activities against glycogen phosphorylase in the direction of glycogen synthesis by the release of phosphate from glucose-1-phosphate were evaluated, and 4m is the most potent GPa inhibitor.
TL;DR: The absorption spectra show that the postannealing treatments above 400 masculineC temperature can remove the color centers induced by implantation efficiently and propagation loss and near-field profiles of the planar waveguide were obtained with an end-face coupling system.
Abstract: We report on the fabrication of planar waveguide in stoichiometric lithium niobate by 500 keV proton implantation with a dose of 1x10(17) ions/cm(2). The formation of n(e) enhancement planar waveguide in the crystal was disclosed by the dark mode spectra and the subsequent endface coupling measurement. The absorption spectra show that the postannealing treatments above 400 masculineC temperature can remove the color centers induced by implantation efficiently. The propagation loss and near-field profiles of the planar waveguide were obtained with an end-face coupling system.
TL;DR: During the first 100 days following nonmyeloablative allo-PBSCT in patients with CML, a 38% incidence of renal dysfunction and a 19% of acute renal failure were found, which were much less than previous studies.
Abstract: Background: Renal insufficiency is a common complication early after hematopoietic stem cell transplantation (HSCT). Over the past several years, significant advancement has been ac
TL;DR: This study provides a new template for further development of potent antitumor drugs by synthesizing a series of novel 3,5-substituted indolin-2-one compounds, featuring the 3,--+ 2-one core and β-pyrrole group, based on enzyme binding features of (Z)-SU5402.
Abstract: Aim: To design and synthesize a novel class of antitumor agents, featuring the 3,
5-substituted indolin-2-one framework. Methods: Based on enzyme binding features
of (Z)-SU5402, introducing a β-pyrrole group at the 3-position of the indolin-
2-one core, a series of novel 3,5-substituted indolin-2-ones were designed and
synthesized. Four human carcinoma cell lines of A-431, A-549, MDA-MB-468,
and Autosomal Dominant Polycystic Kidney disease were chosen for the cell
proliferation assay. Results: Twenty new compounds (1a–t) with E configuration
have been designed, synthesized and bioassayed. Their structural features were
determined by nuclear magnetic resonance (NMR) spectra, low- and high-resolution
mass spectra, and confirmed by X-ray crystallography. Although the enzyme
assay showed a weak inhibition effect against the epidermal growth factor receptor,
vascular endothelial growth factor receptor, fibroblast growth factor receptor and
platelet-derived growth factor receptor tyrosine kinases, the cell-based antitumor
activity was promising. Compounds 1g and 1h showed higher inhibitory activity
toward the A-549 and MDA-MB-468 cell lines with IC 50 of 0.065–9.4 μmol/L.
Conclusion: This study provides a new template for further development of
potent antitumor drugs.
TL;DR: In this article, the treatment of aryl acyloin (α-hydroxyketone) O−alkyl and O−phenyl derivatives with 2-3 equiv of Zn and 1 2 -equiv of NH4Cl in ethanol, refluxing for 20-120 min, gave the corresponding ketones with excellent yields.
TL;DR: Perceived shifts of fruiting body formation abilities and motilities discovered in the salt-tolerant Myxococcus strains suggested an ecological adaptation of myxobacterial social behaviors to the marine environments.
Abstract: More and more studies have indicated that myxobacteria are able to live in seawater conditions, which, however, can decrease the fruiting body formation ability and also the adventurous (A) and social (S) motility systems of the myxobacteria. To learn the adaptation mechanism of the salt-tolerant myxobacteria to marine conditions, we analyzed 10 salt-tolerant Myxococcus strains of their fruiting body formation and motility. The isolates were from marine samples and possessed different levels of salt tolerance. They had the dual motility system and formed fruiting bodies in the presence of suitable seawater concentrations. Some high salt-tolerant strains even lost their fruiting abilities in the absence of seawater. In response to the presence of seawater, the S-motility was found to be increased in the high salt-tolerants but decreased in the low salt-tolerants. The A-motility, on the other hand, was observed in all the salt-tolerant Myxococcus strains, but increased or decreased in response to the presence of seawater. Perceived shifts of fruiting body formation abilities and motilities discovered in the salt-tolerant Myxococcus strains suggested an ecological adaptation of myxobacterial social behaviors to the marine environments.
TL;DR: In this paper, cyclic secondary amines in pyridine at room temperature for 24h afforded unusual products (2a-g). Related experiments were carried out to explain the formation of 4amination and 2-O-deacetylation of peracetylated sialic acid derivatives.
TL;DR: The mts locus in salt-tolerant Myxococcus fulvus HW-1 was found to be critical for gliding motility, fruiting-body formation, and sporulation and the mts genes were determined to be involved in cell-cell cohesion in both myxobacterial species.
Abstract: The mts locus in salt-tolerant Myxococcus fulvus HW-1 was found to be critical for gliding motility, fruiting-body formation, and sporulation. The homologous genes in Myxococcus xanthus are also important for social motility and fruiting-body development. The mts genes were determined to be involved in cell-cell cohesion in both myxobacterial species.
Journal Article•
TL;DR: A review of the progress of multianalyte immunoassay and its applications in different fields with 90 references is given in this article, where the outlook of this promising technique has been discussed.
Abstract: Multianalyte immunoassay has gained increasing attention due to its high sample throughput, short assay time, low sample consumption and reduced overall cost per assay. Most of the current developed approaches for multianalyte immunoassay are based on spatial-resolved, multilabel or separation mode. This paper reviews the progress of multianalyte immunoassay and its applications in different fields with 90 references. The outlook of this promising technique has been discussed.
TL;DR: In this paper, an experimental study of electrochemical deposition was carried out in an ultra-thin layer of CuSO 4 solution, using an unique experimental setup, the convectional interferences in the deposit growth process are effectively restrained.
TL;DR: In this paper, cyclic secondary amines in pyridine at room temperature for 24h afforded unusual products (2a-g). Related experiments were carried out to explain the formation of 4amination and 2-O-deacetylation of peracetylated sialic acid derivatives.
Abstract: Treatment of methyl 5-acetamido-2,4,7,8,9-penta-O-acetyl-3,5-dideoxy-β- l -glycero- d -galacto-2-nonulopyranosidonate (1) with cyclic secondary amines in pyridine at room temperature for 24 h afforded unusual products (2a–g). Related experiments were carried out to explain the formation of 4-amination and 2-O-deacetylation of peracetylated sialic acid derivatives (2a–g). This reaction may provide a new strategy for the preparation of Zanamivir analogues as neuraminidase inhibitors for anti-H5N1 subtype of avian influenza virus (AIV).
TL;DR: In this article, the effect of implantation of H ions in the SiGe-on-insulator (SGOI) materials was discussed, and it was shown that H ions decreased the oxidation rate of SiGe layers and decreased the loss of Ge in SiGe layer during oxidation.
TL;DR: In this paper, 16 4-triazole-modified zanamivir analogues were synthesized using click reactions, and their inhibitory activities against avian influenza virus (AIV, H5N1) were determined.
Abstract: Sixteen novel 4-triazole-modified zanamivir (1) analogues were synthesized using the click reactions, and their inhibitory activities against avian influenza virus (AIV, H5N1) were determined. Compound 3b exerts promising inhibitory activity with EC50 of 6.4 μM, which is very close to that of zanamivir (EC50 = 2.8 μM). Molecular modeling provided the information about the binding model between inhibitors and neuraminidase, which are in good agreement with inhibitory activities.
TL;DR: The title compound, {[Ba2(C(13)H(8)N(2)O(6)S)2(H2O)6]n, possesses a novel two-dimensional porous coordination network, in which each Ba(II) ion is nine-coordinated by three carboxylate O atoms, two sulfonate O atom and four water molecules in an irregular coordination environment.
Abstract: The title compound, {[Ba2(C(13)H(8)N(2)O(6)S)2(H2O)6].C(10)H(8)N(2)}n, possesses a novel two-dimensional porous coordination network, in which each Ba(II) ion is nine-coordinated by three carboxylate O atoms, two sulfonate O atoms and four water molecules in an irregular coordination environment. Hydrogen-bond interactions between coordinated water molecules and sulfonate/hydroxyl groups hold the network layers together and produce a three-dimensional supramolecular architecture.
TL;DR: In this paper, the treatment of aryl acyloin (α-hydroxyketone) O−alkyl and O−phenyl derivatives with 2-3 equiv of Zn and 1 2 -equiv of NH4Cl in ethanol, refluxing for 20-120 min, gave the corresponding ketones with excellent yields.
Abstract: The treatment of aryl acyloin (α‐hydroxyketone) O‐alkyl and O‐phenyl derivatives with 2–3 equiv of Zn and 1–2 equiv of NH4Cl in ethanol, refluxing for 20–120 min, gave the corresponding ketones with excellent yields. Further, α,β‐epoxy ketones can be efficiently transformed to β‐hydroxy ketones, and 2,2‐dialkoxy‐1‐phenyl ketone also can be dealkoxylated to 1‐phenyl ketone.