Pei-Quan Chen

Nankai University, Tianjin, Tianjin Shi, China

Are you Pei-Quan Chen?

Claim your profile

Publications (8)17.15 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Ketol-acid reductoisomerase (KARI; EC 1.1.1.86) catalyzes the second common step in branched-chain amino acid biosynthesis. This enzyme is an important target for drug design. Based on the crystal structure of ketol-acid reductoisomerase/N-hydroxy-N-isopropyloxamate (IpOHA) complex, we have carried out high throughput receptor-based virtual screening of the ZINC/drug like database (2 000 000 compounds) to look for novel inhibitors of KARI for the first time. Some novel compounds were found to inhibit rice KARI in vitro among 15 procured compounds. This method can provide useful information for further design and discovery of KARI inhibitors.
    Chemical Biology &amp Drug Design 12/2009; 75(2):228-32. · 2.47 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Ketol-acid reductoisomerase (KARI; EC 1.1.1.86) catalyzes the second common step in branched-chain amino acid biosynthesis. The catalyzed process consists of two steps, the first of which is an alkyl migration from one carbon atom to its neighboring atom. The likely transition state is a cyclopropane derivative, thus a new series of cyclopropanecarbonyl thiourea derivatives were designed and synthesized involving a one-pot phase transfer catalyzed reaction. Rice KARI inhibitory activity of these compounds were evaluated and the 5-butyl substituted (3e) and 3-pyridinyl substituted (3n) compounds reached 100% at 100 microg x mL(- 1). Structure-activity relationship shows that longer chain derivatives had higher KARI inhibitory activity. Meanwhile substitution of the 4-position of the benzene ring had higher KARI inhibitory activity than that of the 2 and 3-position. Auto-Dock was used to predict the binding mode of 3n. This was done by analyzing the interaction of compound 3n with the active sites of the available spinach KARI. This was in accord with the results analyzed by the frontier molecular orbital theory.
    Journal of Enzyme Inhibition and Medicinal Chemistry 10/2008; 24(2):545-52. · 1.50 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A novel phosphorus derivative was synthesized through HTVS. The title compounds were confirmed by MS, H NMR, P NMR. The DOCK was also studied.
    Phosphorus Sulfur and Silicon and the Related Elements 01/2008; 183:775-778. · 0.60 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The reaction of AgNO3 with bulky anthracene-9-carboxylic acid (HL1) in the presence of 2,6-dimethylpyridine (dmp) afforded a photoluminescent hexanuclear discrete AgI complex [Ag6(L1)6(dmp)2] exhibiting C–H⋯Ag interactions whose total interaction energy were further estimated by DFT calculations. The relevant results reveal that the steric bulk of the anthracene ring skeleton of L1 may play important roles in the formation of the final structure.
    Inorganic Chemistry Communications - INORG CHEM COMMUN. 01/2008; 11(2):159-163.
  • [Show abstract] [Hide abstract]
    ABSTRACT: To systematically investigate the influence of ligands with a large conjugated π-system on the structures and properties of their complexes, we synthesized seven ZnII complexes with two anthracene-based carboxylic ligands, anthracene-9-carboxylic acid (HL1) and anthracene-9,10-dicarboxylic acid (H2L2), and sometimes incorporating different auxiliary ligands, {[Zn(L1)2(H2O)2](H2O)}∞ (1), [Zn5(μ3-OH)2(L1)8(2,2′-bipy)2] (2), Zn2(L1)4(phen)2(μ-H2O) (3), {[Zn(L1)2(4,4′-bipy)(CH3OH)2]}∞ (4), {[Zn(L2)2](Hdmpy)2(H2O)2}∞ (5), {[Zn2(L2)(2,2′-bipy)4](HL2)2}∞ (6) and {[Zn2(L2)(pypz)2(Hpypz)2]}∞ (7) (2,2′-bipy = 2,2′-bipyridine, phen = 1,10′-phenanthroline, Hpypz = 3-(2-pyridyl)pyrazole, 4,4′-bipy = 4,4′-bipyridine and Hdmpy = protonated 2,6-dimethylpyridine), which were characterized by elemental analyses, IR spectroscopy, and X-ray crystallography. 1 has a one-dimensional (1-D) chain structure, whereas 2 exhibits a new pentanuclear cluster structure because of the introduction of a chelating 2,2′-bipy ligand. 3 and 4 take dinuclear and 1-D structures, respectively, by incorporating the auxiliary ligands phen and 4,4′-bipy. 5 is a three-dimensional (3-D) twofold interpenetrating diamondoid framework showing an open channel. 6 and 7 possess the corresponding chain structures containing Zn2 units as nodes by introducing Hpypz and 4,4′-bipy auxiliary ligands, respectively. These results indicate that the nature of ligands and auxiliary ligands has an important effect on the structural topologies of such complexes. Moreover, the luminescent properties of the corresponding complexes and ligands have been briefly investigated.
    CrystEngComm 01/2008; 10(6). · 3.88 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Ketol-acid reductoisomerase (KARI; EC 1.1.1.86) catalyzes the second common step in branched-chain amino acid biosynthesis. The catalyzed process consists of two stages, the first of which is an alkyl migration from one carbon atom to its neighbouring atom. The likely transition state is a cyclopropane derivative, thus a series of new cyclopropane derivatives, such as 1-cyano-N-substituted-cyclopropanecarboxamide, were designed and synthesized. Their structures were verified by (1)H NMR, FTIR spectrum, MS and elemental analysis. The K(i) values of active compounds 2, 4b against rice KARI were 95.30+/-13.71, 207.9+/-21.99 microM, respectively. The X-ray crystal structure of compound 4a was also determined. Auto-Dock was used to predict the binding mode of 4a. This was done by analyzing the interaction of the compounds 4a with the active sites of spinach KARI. This result was in accord with the result analyzed by the frontier molecular orbital theory.
    Bioorganic & Medicinal Chemistry Letters 08/2007; 17(13):3784-8. · 2.34 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In our efforts to investigate the coordination architectures of transition metals and organic ligands with tailored structures, we have prepared two structurally related rigid bulky acridine-based ligands, 9-[3-(2-pyridyl)pyrazol-1-yl]- acridine (L(1)) and 9-(1-imidazolyl)acridine (L2), and synthesized and characterized four of their Ag(I) complexes, {[AgL1](ClO4)}2 (1), {[AgL1](NO3)}2 (2), [AgL2(2)](ClO4) (3), and {[(Ag3L2(3))(NO3)](NO3)2(H2O)}(infinity) (4). The single-crystal X-ray diffraction analysis shows that the structures of 1 and 2 are similar to each other, with the two intramolecular Ag(I) centers of each complex being encircled by two L1 ligands; this forms a unique boxlike cyclic dimer, which is further linked to form one-dimensional (1D) chains of 1 and a two-dimensional (2D) network of 2 by intermolecular face-to-face pi...pi stacking and/or weak C-H...O hydrogen-bonding interactions, respectively. 3 has a mononuclear structure, which is further assembled into a 2D network via intermolecular Ag...O and pi...pi stacking weak interactions. 4 possesses two different 1D motifs that are further interlinked through interlayer face-to-face pi...pi stacking and Ag...O weak interactions, resulting in a 2D network. It is worth noting that one of the interesting structural features of 1, 2, and 4 is the presence of obvious C-H...M hydrogen-bonding interactions between the Ag centers and some acridine ring H atoms identified by X-ray diffraction on the basis of the van der Waals radii. Furthermore, as a representative example, full geometry optimization on the basis of the experimental structure, the natural bond orbital (NBO), and topological analysis of 1 were carried out by DFT and AIM (Atoms in Molecules) calculations. The total C-H...Ag interaction energy in 1 is estimated to be about 14 kJ/mol. Therefore, this work offers three new rare examples (1, 2, and 4) that exhibit C-H...Ag weak interactions, in which the N donors of the acridine rings coordinate to Ag(I) ions. Also, these results strongly support the existence of C-H...Ag close interactions and allow us to have a better understanding of the nature of such interactions in the coordination supramolecular systems.
    Inorganic Chemistry 08/2006; 45(15):5812-21. · 4.59 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A novel cyclopropane derivative, 1-cyano-N-p-tolylcyclopropanecarboxamide (C12H12N2O, Mr=200.24) was synthesized and its structure was studied by X-ray diffraction, FTIR, 1H and 13C NMR spectrum and MS. The crystals are monoclinic, space group P2_1/c with a=7.109 (4), b=13.758 (7), c=11.505 (6) Å, α=90.00, β=102.731 (8), γ=90.00°, V=1097.6 (9) Å3, Z=4, F(000)=312, D c =1.212g/cm3, μ=0.0800mm−1, the final R=0.0490 and wR=0.1480 for 1,375 observed reflections with I>2σ(I). A total of 6,109 reflections were collected, of which 2,290 were independent (R int=0.0290). Theoretical calculation of the title compound was carried out with HF/6-31G (d,p), B3LYP/6-31G (d,p), MP2/6-31G (d,p). The full geometry optimization was carried out using 6-31G(d,p) basis set, and the frontier orbital energy. Atomic net charges were discussed, and the structure-activity relationship was also studied. The preliminary biological test showed that the synthesized compound is bioactive against the KARI of Escherichia coli.
    Structural Chemistry 18(5):563-568. · 1.77 Impact Factor