The discovery of 3-(1-aminoethylidene)quinoline-2, 4(1H,3H)-dione derivatives as novel PSII electron transport inhibitors

Based on the structures of the 4-hydroxyphenylpyruvate dioxygenase inhibitor mesotrione and natural product fischerellin A, a series of imine derivatives of ( $E$ )-3-acyl-quinoline-2,4(1H,3H)-dione (6, 12 and 16) were designed, synthesized and systematically evaluated for their herbicidal activity. The bioassay results indicated that most of the synthesized compounds displayed good to excellent herbicidal activity, of which 6e, 6g, 6h, 6q and 6t exhibited more than 50 % inhibition against Brassica napus L., Amaranthus retroflexu or Digitaria adscendens at a dosage of $94\,\hbox {g}\,\hbox {ha}^{-1}$ or lower. The symptom of injured leaves in vivo, the high Hill reaction inhibitory activity of 6h in vitro ( $\hbox {IC}_{50}\,0.1\, \upmu \hbox {g}\,\hbox {mL}^{-1})$ and the computer-based binding model of compound 6h with D1 protein in photosystem II (PSII) reaction centre suggest this novel structure to likely be a new type of PSII electron transport inhibitor. Thus, we have found a novel type of diketone enamine structure targeted at the PSII reaction centre.     

2D-SAR and 3D-QSAR analyses for acetylcholinesterase inhibitors

Alzheimer’s disease (AD) accounts for almost three quarters of dementia patients and interferes people’s normal life. Great progress has been made recently in the study of Acetylcholinesterase (AChE), known as one of AD’s biomarkers. In this study, acetylcholinesterase inhibitors (AChEI) were collected to build a two-dimensional structure–activity relationship (2D-SAR) model and three-dimensional quantitative structure–activity relationship (3D-QSAR) model based on feature selection method combined with random forest. After calculation, the prediction accuracy of the 2D-SAR model was 89.63% by using the tenfold cross-validation test and 87.27% for the independent test set. Three cutting ways were employed to build 3D-QSAR models. A model with the highest \({q}^{2}\) (cross-validated correlation coefficient) and \({r}^{2 }\)(non-cross-validated correlation coefficient) was obtained to predict AChEI activity. The mean absolute error (MAE) of the training set and the test set was 0.0689 and 0.5273, respectively. In addition, molecular docking was also employed to reveal that the ionization state of the compounds had an impact upon their interaction with AChE. Molecular docking results indicate that Ser124 might be one of the active site residues.     

4-氟苯甲醛酪氨酸席夫碱的制备及其振动光谱的密度泛函理论和从头算理论计算的研究

4-氟苯甲醛酪氨酸席夫碱(4-FT)由4-氟苯甲醛和L-酪氨酸钾盐在室温条件下反应制得,4-FT的结构通过1HNMR,FTIR和Raman测试得到确认。分别用密度泛函(DFT,density functional theory)理论的B3LYP(Becke’s three-parameter exchange functional(B3)with Lee,Yang,Parr(LYP))方法和从头算(ab initio)理论的HF(Hartree-Fock)方法,选用标准的6-31G**和6-31G*基组对化合物4-FT的几何构型进行优化。同时分别在B3LYP/6-31G**,B3LYP/6-31G*,HF/6-31G**和HF/6-31G*水平下计算4-FT的振动波数。用密度泛函(DFT)的B3LYP方法计算并校正后的波长数据比用从头算(ab i-nitio)的HF方法计算的结果更与实验数据吻合。     

Discovery of 5-methyl-2-(4-((4-(methylsulfonyl)benzyl)oxy)phenyl)-4-(piperazin-1-yl)pyrimidine derivatives as novel GRP119 agonists for the treatment of diabetes and obesity

A series of fused-pyrimidine derivatives were prepared and evaluated for their agonistic activities against human GPR119. Compound 9i showed high potent agonistic activity against HEK293T cells over-expressing human GPR119 and improved glucose tolerance in dose-dependent manner, as well as promoted insulin secretion. In a DIO mice model, 9i also ameliorated the obese-related symptoms by decreasing the body weights without markedly changing food intake, normalized some serum biomarkers, such as ALT, AST, ALP, GLU, CHOL, HDL, and LDL, and exerted therapeutic activity on fat deposition in liver tissue. We consider 9i to have utility as a GPR119 agonists for the treatment of type 2 diabetes mellitus and obese-related symptoms.     

A novel and convenient synthesis of 4-hydroxy-6-methyl-3-(1-(phenylimino) ethyl)-2H-pyran-2-one derivatives under ultrasound irradiation

A facile, efficient and environment-friendly protocol for the synthesis of 4-hydroxy-6-methyl-3-(1-(phenylimino)ethyl)-2H-pyran-2-one derivatives has been developed by the convenient ultrasound-mediated condensation of amine with dehydroacetic acid. This method provides several advantages over current reaction methodologies including a simple work-up procedure, shorter reaction times and higher yields.     

5,6-二氢-2-吡喃酮作为HIV-1蛋白酶抑制剂的3D-QSAR和对接研究

本文采用分子对接法研究了24个5,6-二氢-2-吡喃酮衍生物与HIV-1蛋白酶的相互作用,并采用三维定量构效关系(3D-QSAR)研究了药物分子化学结构和生物活性之间的关系.最终得到模型的复相关系数(R_(cum)~2)为0.961、留一法交互校验复相关系数(Q_(cv)~2)为0.897,外部交互验证复相关系数(Q_(ext)~2)为0.880,从结果可以看出三维定量构效关系对化合物的抗艾滋病活性具有比较好的预测能力.然后通过分子对接研究了配体小分子和HIV-1蛋白酶活性氨基酸残基之间的结合模式,这些信息对于以后设计合成新的抗艾滋病药物具有一定的指导作用.     

Dehydroabietylamine-based thiazolidin-4-ones and 2-thioxoimidazolidin-4-ones as novel tyrosyl-DNA phosphodiesterase 1 inhibitors

Molecular Diversity - Tyrosyl-DNA phosphodiesterase 1 (TDP1) is a DNA repair enzyme that plays a key role in repairing damage caused by various antitumor drugs. It is a promising target in...     

Eco-friendly synthesis,in vitro anti-proliferative evaluation,and 3D-QSAR analysis of a novel series of monocationic 2-aryl/heteroaryl-substituted 6-(2-imidazolinyl)benzothiazole mesylates

Abstract

Herein, we describe the synthesis of twenty-one novel water-soluble monocationic 2-aryl/heteroaryl-substituted 6-(2-imidazolinyl)benzothiazole mesylates 3a–3u and present the results of their anti-proliferative assays. Efficient syntheses were achieved by three complementary simple two-step synthetic protocols based on the condensation reaction of aryl/heteroaryl carbaldehydes or carboxylic acid. We developed an eco-friendly synthetic protocol using glycerol as green solvent, particularly appropriate for the condensation of thermally and acid-sensitive heterocycles such as furan, benzofuran, pyrrole, and indole. Screening of anti-proliferative activity was performed on four human tumour cell lines in vitro including pancreatic cancer (CFPAC-1), metastatic colon cancer (SW620), hepatocellular carcinoma (HepG2), and cervical cancer (HeLa), as well as in normal human fibroblast cell lines. All tested compounds showed strong to moderate anti-proliferative activity on tested cell lines depending on the structure containing aryl/heteroaryl moiety coupled to 6-(2-imidazolinyl)benzothiazole moiety. The most potent cytostatic effects on all tested cell lines with \(\hbox {IC}_{50}\) values ranging from 0.1 to 3.70 \(\upmu \hbox {M}\) were observed for benzothiazoles substituted with naphthalene-2-yl 3c, benzofuran-2-yl 3e, indole-3-yl 3j, indole-2-yl 3k, quinoline-2-yl 3s, and quinoline-3-yl 3t and derivatives substituted with phenyl 3a, naphthalene-1-yl 3b, benzothiazole-2-yl 3g, benzothiazole-6-yl 3h, N-methylindole-3-yl 3l, benzimidazole-2-yl 3n, benzimidazole-5(6)-yl 3o, and quinolone-4-yl 3u with \(\hbox {IC}_{50}\) values ranging from 1.1 to 29.1 \(\upmu \hbox {M}\). Based on obtained anti-proliferative activities, 3D-QSAR models for five cell lines were derived. Molecular volume, molecular surface, the sum of hydrophobic surface areas, molecular mass, and possibility of making dispersion forces were identified by QSAR analyses as molecular properties that are positively correlated with anti-proliferative activity, while compound’s capability to accept H-bond was identified as a negatively correlated property. Comparison of molecular properties identified for different cell lines enabled assumptions about similarity of mode of action through which anti-proliferative activities against different cell lines are accomplished. Novel compounds that are predicted to have enhanced activities in comparison with herein presented ones were designed using 3D-QSAR analysis as guideline.

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Quantum-chemical study of structure and spectral properties of triphenylamine-rhodanine dye 2-(5-(4-(diphenylamine)benzylidene)-4-oxo-2-thioxothiazolidine-3-yl) acetic acid

The structure and optical properties of triphenylamine-rhodanine dye 2-(5-(4-(diphenylamine)benzylidene)-4-oxo-2-thioxothiazolidine-3-yl) acetic acid, which is used as a sensitizer for nanocrystalline TiO₂ solar cells, are studied based on the density functional theory. The nature of the absorption of this dye in the visible and near UV regions is discussed within the time-dependent density functional theory (TDDFT). The calculations of the vertical excitation energies of the dye molecule taking into account the effect of solvent reveal a strong positive solvatochromic effect compared to the calculations in the vacuum approximation. The IR absorption bands of this dye in the region of 600–1850 cm⁻¹ are completely interpreted.     

Structure of 2-(2-(anthracen-9-ylmethylene)hydrazinyl)-4-(3-methyl-3-phenylcyclobutyl)thiazole by combined X-Ray crystallographic and molecular modelling studies

A single crystal of 2-(2-(anthracen-9-ylmethylene)hydrazinyl)-4-(3-methyl-3-phenylcyclobutyl)thiazole (C₂₉H₂₅N₃S) containing anthracene, thiazole and cyclobutane rings has been synthesised. The synthesised crystal structure was characterised using IR, ¹H-NMR and ¹³C-NMR spectroscopic and X-Ray analysis techniques. In the crystal, neighbouring molecules formed chains along [110] by interconnecting with N–H···N hydrogen bonding and π–π interactions. The geometrical parameters of the title compound were optimised by Gaussian 09 software in the gas phase and Quantum-Espresso software under Periodic Boundary Conditions (PBC) in the solid phase. Theoretically, IR, NMR spectra, Mulliken, NPA and AIM atomic charges, Hirshfeld surface and frontier molecular orbitals (FMOs) of the title compound were examined. Using the Hirshfeld surface and two-dimensional (2D) fingerprint graphics, the presence of intermolecular interactions in the crystal packing were analysed. The energies of these interactions and their distribution on the crystal structure were shown graphically. In general, it was seen that theoretical calculations were consistent with X-Ray results.     

类镓等电子序列ZrX—RhXV离子的4s^24p—4s^24d,4s^24p—4s4p^2,4s^24 …

本文对类镓等电子序列ＧａＩ－ＸｅＸＸＩＶ离子４ｓ＾２４ｐ、４ｓ＾２４ｐ、４ｓ＾２４ｄ、４ｓ４ｐ＾２、４ｐ＾３和４ｓ＾２５ｓ组态组级结果和组态相互作用了理论分析，找出沿等电子序列的变化规律。     

De novo design of N-(pyridin-4-ylmethyl)aniline derivatives as KDR inhibitors: 3D-QSAR, molecular fragment replacement, protein-ligand interaction fingerprint, and ADMET prediction

Vascular endothelial growth factor (VEGF) and its receptor tyrosine kinase VEGFR-2 or kinase insert domain receptor (KDR) have been identified as promising targets for novel anticancer agents. To achieve new potent inhibitors of KDR, we conducted molecular fragment replacement (MFR) studies for the understanding of 3D-QSAR modeling and the docking investigation of arylphthalazines and 2-((1H-Azol-1-yl)methyl)-N-arylbenzamides-based KDR inhibitors. Two favorable 3D-QSAR models (CoMFA with q ², 0.671; r ², 0.969; CoMSIA with q ², 0.608; r ², 0.936) have been developed to predict the biological activity of new compounds. The new molecular database generated by MFR was virtually screened using Glide (docking) and further evaluated with CoMFA prediction, protein?Cligand interaction fingerprint (PLIF) and ADMET analysis. 44 N-(pyridin-4-ylmethyl)aniline derivatives as novel potential KDR inhibitors were finally obtained. In this paper, the work flow developed could be applied to de novo drug design and virtual screening potential KDR inhibitors, and use hit compounds to further optimize and design new potential KDR inhibitors.     

Widely tunable broadband terahertz radiation generation using a configurationally locked polyene 2-[3-(4-hydroxystyryl)-5,5-dimethylcyclohex-2-enylidene] malononitrile crystal via difference frequency generation

Widely tunable terahertz (THz) waves were successfully generated from 0.5 to 10 THz via difference frequency generation (DFG) in a configurationally locked polyene 2-[3-(4-hydroxystyryl)-5,5-dimethylcyclohex-2-enylidene] malononitrile (OH1) crystal. Potassium titanium oxide phosphate optical parametric oscillator pumped by nanosecond Q-switched Nd:YAG laser was used to generate two waves, which were then used to irradiate OH1 crystal. The maximum energy of the generated THz wave was about 461 pJ/pulse. We investigated the dependency of generated THz energy to the excitation pump power density and OH1 crystal thickness. In addition, we compared the THz energy generated by OH1 crystal to 4-N,N-dimethylamino-4′-N′-methyl-4-stilbazolium tosylate (DAST) crystal using DFG, and we achieved 560 times higher energy using OH1 crystal than DAST crystal at around 1.1 THz.     

4-(4-氨基苯基)-3-吗啉酮的合成

4-(4-氨基苯基)-3-吗啉酮是合成利伐沙班的一个重要中间体,以吗啉酮为原料,利用Buchwald-Hartwig偶联反应制得4-苯基-3-吗啉酮,再经硝化,还原三步反应制备4-(4-氨基苯基)-3-吗啉酮。     

An unusual synthesis of 3-(2-(arylamino)thiazol-4-yl)-2H-chromen-2-ones from ethyl 2-(chloromethyl)-2-hydroxy-2H-chromene-3-carboxylate via benzopyran ring opening

An unusual and unexpected synthesis of 3-(2-(arylamino)thiazol-4-yl)-2H-chromen-2-ones has been observed by the reaction of ethyl 2-(chloromethyl)-2-hydroxy-2H-chromene-3-carboxylate with various arylthioureas in ethanol under mild reaction conditions with excellent yields. The ambiguity in the structure of the obtained products has been solved by recording its single-crystal X-ray analysis. This protocol has been found to be a novel approach for the preparation of title compounds via benzopyran ring opening. A systematic plausible mechanism has been proposed for the formation of the product. Also, an efficient one-pot three-component method has been demonstrated for the formation of title compounds starting from salicylaldehyde.