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1.
Acta Crystallogr C Struct Chem ; 76(Pt 1): 75-86, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31919310

RESUMO

Structural and theoretical studies of four novel 5,6-dehydronorcantharidine (DNCA)/norcantharidine (NCA) derivatives, namely (3aR,4S,7R,7aS)-2-phenyl-3a,4,7,7a-tetrahydro-4,7-epoxy-1H-isoindole-1,3(2H)-dione, C14H11NO3 (DNCA-A), (3aR,4S,7R,7aS)-2-(4-nitrophenyl)-3a,4,7,7a-tetrahydro-4,7-epoxy-1H-isoindole-1,3(2H)-dione, C14H10N2O5 (DNCA-NA), (3aR,4S,7R,7aS)-2-(4-nitrophenyl)-3a,4,5,6,7,7a-hexahydro-1H-4,7-epoxyisoindole-1,3(2H)-dione, C14H12N2O5 (NCA-NA), and (3aR,4S,7R,7aS)-2-(2-hydroxyethyl)-3a,4,5,6,7,7a-hexahydro-1H-4,7-epoxyisoindole-1,3(2H)-dione, C10H13NO4 (NCA-AE), are reported. The supramolecular interactions and single-crystal structural characteristics of these molecules, together with the crystal structures of four other similar molecules, i.e. NCA-A (the 4-phenyl derivative of NCA-NA), DNCA-AE (the 5,6-unsaturated derivative of NCA-AE), DNCA and NCA, were analysed. Surprisingly, DNCA-A and NCA-A, as well as DNCA-NA and NCA-NA, proved to be isomorphic, while DNCA-AE and NCA-AE, as well as DNCA and NCA, have very different crystal structures. These are very rare isostructural examples between unsaturated and saturated oxanorbornene/oxanorbornane derivatives. To further explore how noncovalent interactions (NCIs) affect the degree of isomorphism in this particular series of rigid molecules where there is a fairly limited conformational degree of freedom, all four pairs of crystal structures were analyzed in parallel. The differentiation in NCIs which entails the packing mode of similar molecules is supported by energy calculations based on real or exchanged crystal structures. Our results show that minor structural differences may result in very different supramolecular interactions, and so lead to altered packing modes in the crystalline solids. Even if isostructurality sometimes occurs, the possibility of various molecular packing types cannot be ruled out. On the other hand, isomorphism may just be the result of kinetic possibilities instead of relative thermodynamic stabilities. Though crystal structure prediction is formidable, the comparison method based on existing crystal structures and quantum calculations can be used to predict the probability of isomorphism. This understanding will help us to design new norbornene derivatives with specified structures.

2.
Acta Crystallogr C Struct Chem ; 76(Pt 1): 44-63, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31919307

RESUMO

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.


Assuntos
Proliferação de Células/efeitos dos fármacos , Fenilglioxal/análogos & derivados , Bases de Schiff/química , Animais , Linhagem Celular Tumoral , Cristalografia por Raios X/métodos , Humanos , Camundongos , Simulação de Acoplamento Molecular , Estrutura Molecular , Células NIH 3T3 , Fenilglioxal/química , Fenilglioxal/farmacologia , Bases de Schiff/farmacologia , Relação Estrutura-Atividade
3.
Acta Crystallogr C Struct Chem ; 73(Pt 7): 546-555, 2017 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-28677607

RESUMO

A novel and potentially active dihydroorotate dehydrogenase (DHODH) inhibitor, namely 3-({(E)-[(E)-1-(biphenyl-4-yl)ethylidene]hydrazinylidene}methyl)-1H-indole (BEHI) acetonitrile disolvate, C23H19N3·2CH3CN, has been designed and synthesized. The structure of BEHI was characterized by elemental analysis, Q-TOF (quadrupole time-of-flight) MS, NMR, UV-Vis and single-crystal X-ray diffraction. The antitumour activity of the target molecule was evaluated by the MTT method. Results indicated that BEHI exhibited rather potent cytotoxic activity against human A549 (IC50 = 20.5 µM) and mouse breast 4T1 (IC50 = 18.5 µM) cancer cell lines. Meanwhile, to rationalize its potencies in the target, BEHI was docked into DHODH and the interactions with the active site residues were analyzed. Single-crystal structure analysis indicated that hydrogen bonds are present only between BEHI and acetonitrile solvent molecules in the asymmetric unit. The interplay of weak π-π stacking and weak C(N)-H...π interactions between neighbouring BEHI molecules play crucial roles in the formation of the final supramolecular frameworks.

4.
Acta Crystallogr C Struct Chem ; 71(Pt 7): 554-63, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26146393

RESUMO

A series of mono- and di-Schiff bases formed between benzil dihydrazone {BDH; systematic name: (1Z)-[(2E)-2-hydrazinylidene-1,2-diphenylethylidene]hydrazine} and three isomeric chlorobenzaldehydes were designed and synthesized to be used as model compounds to help to explain the reaction mechanisms for the formation of Schiff bases. These compounds are 1-(2-chlorobenzylidene)-2-{2-[2-(2-chlorobenzylidene)hydrazin-1-ylidene]-1,2-diphenylethylidene}hydrazine (BDHOCB), and the 3-chloro (BDHMCB) and 4-chloro (BDHPCB) analogues, all having the formula C28H20Cl2N4. Surprisingly, only di-Schiff bases were obtained; our attempts to push the reaction in favour of the mono-Schiff bases all failed. Density functional theory (DFT) calculations were performed to explain the trend in the experimental results. In the case of the systems studied, the type of Schiff base produced exhibits a clear dependence on the HOMO-LUMO energy gaps (ΔE(HOMO-LUMO)), i.e. the product is mainly governed by its stability. The compounds were characterized by single-crystal X-ray diffractometry, elemental analysis, melting point, (1)H NMR and (13)C NMR spectroscopy. The structural features of the three new Schiff bases are similar. For instance, they have the same chemical formula, all the molecules have a symmetrical double helix structure, with each Ph-C=N-N=C-Ph arm exhibiting an anti conformation, and their supramolecular interactions include intermolecular π-π and weak C-H...π stacking interactions. The crystal systems are different, however, viz. triclinic (space group P1¯) for BDHPCB, monoclinic (space group P2(1)/n) for BDHOCB and orthorhombic (space group Pnna) for BDHMCB.

5.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 4): o970, 2012 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-22590026

RESUMO

The asymmetric unit of the title compound, C(6)H(7)NO(3), contains two mol-ecules (A and B) related by a non-crystallographic twofold pseudo-axis. The mol-ecules are joined in the (AABB)(n) manner by O-H⋯O hydrogen bonds between their hy-droxy groups, thus forming C(2) chains along the a-axis direction. Neighboring mol-ecules of the same kind (A and A, or B and B) are related by inversion centers, so that all hy-droxy H atoms are disordered other two sets of sites with half occupancies (superimposed O-H⋯O and O⋯H-O fragments). The mol-ecules are further linked by C-H⋯O inter-actions, which can be considered to be weak hydrogen bonds.

6.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 3): o866, 2012 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-22412720

RESUMO

In the crystal of the title compound, C(10)H(11)NO(4), the hy-droxy group forms an O-H⋯O(carbon-yl) hydrogen bond with an adjacent molecule, so forming chains which extend along (010). Further weak C-H⋯O hydrogen-bonding associations give an infinite three-dimensional network structure.

7.
Acta Crystallogr C ; 67(Pt 7): m218-20, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21727615

RESUMO

The title coordination polymer, {[Ag(C(8)H(7)O(5))]·H(2)O}(n), is built from Ag(+) cations and singly protonated dehydronorcantharidin (SP-DNC) anions, with a distorted trigonal-planar geometry at the metal centre. The coordination number of Ag(I) is three (with one Ag-π bond and two Ag-O bonds, one from each of three different SP-DNC ligands), if only formal Ag-ligand bonds are considered, but can be regarded as five if longer weak Ag···O interactions are also included. The two-dimensional corrugated-sheet coordination polymer forms a non-interpenetrating framework with (4.8(2)) topology. Disordered water molecules are sandwiched between the sheets.


Assuntos
Íons/química , Compostos Organometálicos/química , Polímeros/química , Prata/química , Cristalografia por Raios X , Ligantes , Estrutura Molecular
8.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 9): o2192, 2009 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-21577596

RESUMO

The asymmetric unit of the title compound, C(20)H(15)NO(2), contains one half-molecule with the central N atom and two C atoms of the benzene moiety lying on a twofold rotation axis. Weak C-H⋯O inter-actions join the mol-ecules together into an infinite three-dimensional network.

9.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 11): o2902, 2009 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-21578484

RESUMO

The title compound, C(6)H(6)N(2)O(2), is approximately planar [r.m.s. deviation = 0.0488 (3) Å]. In the crystal, weak inter-molecular C-H⋯O and C-H⋯N inter-actions join the mol-ecules into an infinite three-dimensional network.

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