Staphylococci are facultative anaerobes, perfectly spherical un-encapsulated cocci, with a diameter not exceeding 1 micrometer in diameter. Staphylococcus aureus are generally harmless and remain confined to the skin unless they burrow deep into the body, causing life-threatening infections in bones, joints, bloodstream, heart valves and lungs. Among the 20 medically important staphylococci species, Staphylococcus aureus is one of the emerging human pathogens. Streptomycin had its highest potency against Staphylococcus infections despite the likelihood of getting a resistant type of staphylococcus strains. Methicillin-resistant S. aureus (MRSA) is the persister type of Staphylococcus aureus and was evolved after decades of antibiotic misuse. Inadequate penetration of the antibiotic is one of the principal factors related to success/failure of the therapy. The active drug needs to reach the bacteria at concentrations necessary to kill or suppress the pathogen's growth. In turn the effectiveness of the treatment relied on the physical properties of Staphylococcus aureus. Thus understanding the cell integrity, shape and roughness is crucial to the overall influence of the therapeutic agent on S. aureus of different origins. Hence our experiments were designed to clarify ultrastructural changes of S. aureus treated with streptomycin (synthetic compound) in comparison to artonin E (natural compound). In addition to the standard in vitro microbial techniques, we used transmission electron microscopy to study the disrupted cell architecture under antibacterial regimen and we correlate this with scanning electron microscopy (SEM) to compare results of both techniques.
The current study investigated the cytotoxic effect of 3-(5-chloro-2-hydroxybenzylideneamino)-2-(5-chloro-2-hydroxyphenyl)-2,3-dihydroquinazolin-41(H)-one (A) and 3-(5-nitro-2-hydroxybenzylideneamino)-2-(5-nitro-2-hydroxyphenyl)-2,3-dihydroquinazolin-4(1H)-one (B) on MCF-7, MDA-MB-231, MCF-10A and WRL-68 cells. The mechanism involved in apoptosis was assessed to evaluate the possible pathways induced by compound A and B. MTT assay results using A and B showed significant inhibition of MCF-7 cell viability, with IC50 values of 3. 27 ± 0.171 and 4.36 ± 0.219 μg/mL, respectively, after a 72 hour treatment period. Compound A and B did not demonstrate significant cytotoxic effects towards MDA-MB-231, WRL-68 and MCF-10A cells. Acute toxicity tests also revealed an absence of toxic effects on mice. Fluorescent microscopic studies confirmed distinct morphological changes (membrane blebbing and chromosome condensation) corresponding to typical apoptotic features in treated MCF-7 cells. Using Cellomics High Content Screening (HCS), we found that compound A and B could trigger the release of cytochrome c from mitochondria to the cytosol. The release of cytochrome c activated the expression of caspases-9 and then stimulated downstream executioner caspase-3/7. In addition, caspase-8 showed remarkable activity, followed by inhibition of NF-κB activation in A-and B-treated MCF-7 cells. The results indicated that A and B could induce apoptosis via a mechanism that involves either extrinsic or intrinsic pathways.
Influenza virus is estimated to cause 3-5 million severe complications and about 250-500 thousand deaths per year. Different kinds of anti-influenza virus drugs have been developed. However, the emergence of drug resistant strains has presented a big challenge for efficient antiviral therapy. Indole derivatives have been shown to exhibit both antiviral and anti-inflammatory activities. In this study, we adopted a cell-based system to screen for potential anti-IAV agents. Four indole derivatives (named 525A, 526A, 527A and 528A) were subjected to the antiviral screening, of which 526A was selected for further investigation. We reported that pre-treating cells with 526A protects cells from IAV infection. Furthermore, 526A inhibits IAV replication by inhibiting the expression of IAV genes. Interestingly, 526A suppresses the activation of IRF3 and STAT1 in host cells and thus represses the production of type I interferon response and cytokines in IAV-infected cells. Importantly, 526A also partially blocks the activation of RIG-I pathway. Taken together, these results suggest that 526A may be a potential anti-influenza A virus agent.
Phytochemicals from Pseuduvaria species have been reported to display a wide range of biological activities. In the present study, a known benzopyran derivative, (6E,10E) isopolycerasoidol (1), and a new benzopyran derivative, (6E,10E) isopolycerasoidol methyl ester (2), were isolated from a methanol extract of Pseuduvaria monticola leaves. The structures of the isolated compounds were elucidated by spectroscopic methods including 1D and 2D NMR, IR, UV, and LCMS-QTOF, and by comparison with previously published data. The anti-proliferative and cytotoxic effects of these compounds on human breast cancer cell-lines (MCF-7 and MDA-MB-231) and a human normal breast epithelial cell line (MCF-10A) were investigated. MTT results revealed both (1) and (2) were efficient in reducing cell viability of breast cancer cells. Flow cytometry analysis demonstrated that (1) and (2) induced cell death via apoptosis, as demonstrated by an increase in phosphotidylserine exposure. Both compounds elevated ROS production, leading to reduced mitochondrial membrane potential and increased plasma membrane permeability in breast cancer cells. These effects occurred concomitantly with a dose-dependent activation of caspase 3/7 and 9, a down-regulation of the anti-apoptotic gene BCL2 and the accumulation of p38 MAPK in the nucleus. Taken together, our data demonstrate that (1) and (2) induce intrinsic mitochondrial-mediated apoptosis in human breast cancer cells, which provides the first pharmacological evidence for their future development as anticancer agents.
In the title compound, [ZnI(2)(C(13)H(19)N(3)O)], the Zn(II) ion is five-coordinated in a distorted square-pyramidal geometry, in which the basal plane is defined by three N atoms from the Schiff base ligand and one iodide ion. A second iodide ligand, situated in the apical position, completes the coordination geometry. In the crystal structure, C-H⋯O hydrogen bonds link a pair of mol-ecules around an inversion centre into a dimer.
In the title compound, [Cd(NCS)(2)(C(11)H(17)N(3))](n), the Cd(II) atom is octa-hedrally coordinated by the N,N',N''-tridentate Schiff base ligand and one terminal thio-cyanate N atom. Two trans-N:S-bridging thio-cyanates complete the N(5)S donor set around the Cd atom. In the crystal, adjacent Cd(II) ions are linked by the thio-cyanate N:S-bridges into polymeric chains along the c axis.
The asymmetric unit of the title compound, [Cu(NCS)(2)(C(11)H(17)N(3))], consists of two crystallographically independent mol-ecules. In each mol-ecule, the Cu(II) ion is five-coordinated in a distorted square-pyramidal geometry wherein the basal plane is defined by the N,N',N"-tridentate Schiff base and one N-bound thio-cyanate ligand. The second N-donor thio-cyanate group, located at the apical site, completes the coordination environment. In the crystal, inter-molecular C-H⋯S and C-H⋯N hydrogen bonds link adjacent mol-ecules into infinite layers parallel to the ac plane. Intra-molecular C-H⋯N inter-actions are also observed.
In the centrosymmetric dinuclear copper(II) title complex, [Cu(2)Br(2)(C(12)H(17)N(2)O)(2)]·H(2)O, each Cu(II) ion is five coordinated in a square-pyramidal geometry by the N,N',O-tridentate Schiff base, one Br atom and the bridging O atom of the centrosymmetrically related Schiff base. In the crystal, the water mol-ecules link the complex mol-ecules into infinite chains along the b axis via O-H⋯Br and C-H⋯O hydrogen bonds.
In the trinuclear title compound, [Zn(3)Cl(6)(C(13)H(20)N(4))(2)]·2H(2)O, each terminal Zn(II) atom is coordinated by an N(3) donor set from the Schiff base ligands and two Cl atoms in a distorted square-pyramidal geometry. The central Zn(II) atom is tetra-hedrally coordinated by two piperazine N atoms from two Schiff base ligands and two Cl atoms. The piperazine rings adopt chair conformations. In the crystal structure, adjacent complex mol-ecules are linked into a three-dimensional network via N-H⋯O, C-H⋯Cl and C-H⋯O hydrogen bonds. The structure includes two water mol-ecules, one of which is disordered over two positions with occupancies of 0.753 (15) and 0.247 (15).
The asymmetric unit of the title compound, [ZnCl(2)(C(11)H(17)N(3))], contains two independent penta-coordinate Zn(II) complex mol-ecules. In each mol-ecule, the metal atom is coordinated by an N,N',N''-tridenate Schiff base and two Cl atoms in a distorted square-pyramidal geometry. The two mol-ecules differ little in their geometry, but more in their inter-molecular inter-actions. In the crystal, adjacent mol-ecules are connected via C-H⋯Cl inter-actions into a three-dimensional supra-molecular structure. The network is supplemented by π-π inter-actions formed between the aromatic rings of pairs of the symmetry-related mol-ecules [centroid-centroid distances = 3.6255 (10) and 3.7073 (10) Å]. The crystal lattice contains void spaces with a size of 52 Å(3).
In the title compound, [CuCl(2)(C(13)H(19)N(3)O)]·H(2)O, the tridentate Schiff base ligand and the two Cl atoms complete a distorted square-pyramidal coordination geometry around the Cu(II) ion in which the three N atoms and one Cl atom are located in the basal plane and the other Cl atom is at the apical position. In the crystal, O-H⋯Cl hydrogen bonds link the complex mol-ecules and the uncoordinated water mol-ecules into infinite chains along the a axis. The chains are further connected into a three-dimensional network via C-H⋯O and C-H⋯Cl inter-actions.
In the title compound, [CdCl(2)(C(6)H(14)N(2)O)(2)], the Cl and Cd(II) atoms are located on a twofold rotation axis and the Cd(II) atom is octa-hedrally coordinated by two N,N'-bidentate 2-(morpholin-4-yl)ethanamine ligands and two trans-located Cl atoms. In the crystal, adjacent mol-ecules are linked by N-H⋯Cl and C-H⋯O hydrogen bonds into a three-dimensional structure. An intra-molecular C-H⋯Cl hydrogen bond is also observed.
The asymmetric unit of the title compound, [Zn(NCS)(2)(C(13)H(19)N(3)O)], contains two crystallographically independent mol-ecules. In each mol-ecule, the Zn(II) ion is five-coordinated by the N,N',N"-tridentate Schiff base and the N atoms of two thio-cyanate ligands in a distorted square-pyramidal geometry. The two mol-ecules differ mainly in the deviations from the ideal geometry, with τ values of 0.14 and 0.33. In the crystal, inter-molecular C-H⋯S hydrogen bonds are observed. An intra-molecular C-H⋯N hydrogen bond occurs in one of the independent mol-ecules.
In the title compound, [CdCl(2)(C(11)H(17)N(3))], the Schiff base acts as an N,N',N''-tridentate ligand towards the Cd(II) ion. Two Cl atoms complete a distorted square-pyramidal geometry around the metal atom. In the crystal, a C-H⋯Cl inter-action connects pairs of mol-ecules into centrosymetric dimers.
The Cd(II) ion in the title compound, [CdBr(2)(C(13)H(19)N(3)O)], is five-coordinated by the N,N',N''-tridentate Schiff base ligand and two Br atoms in a distorted square-pyramidal geometry. In the crystal, inter-molecular C-H⋯O and C-H⋯Br hydrogen bonds link adjacent mol-ecules into layers parallel to the ab plane. An intra-molecular C-H⋯Br inter-action is also observed.
In the title compound, [Cu(C(21)H(22)N(2)O(2))], the cyclo-hexyl ring adopts a chair conformation with the two imine groups linked at equatorial positions. The Cu(II) ion is coordinated by two N atoms and two O atoms from the bis-Schiff base ligand in a slightly distorted square-planar geometry. The dihedral angle between the two benzene rings is 45.89 (9)°. The crystal structure is devoid of any classical hydrogen bonds. However, inter-molecular C-H⋯O inter-actions are present and stabilize the structure.
In the title compound, [Cu(NCS)(2)(C(13)H(19)N(3)O)], the Cu(II) ion is five-coordinated by the N,N',N''-tridentate Schiff base and the N atoms of two isothio-cyanate ligands in a square-pyramidal geometry. In the crystal, C-H⋯N, C-H⋯O and C-H⋯S inter-actions link adjacent mol-ecules into layers parallel to the ac plane. A weak inter-molecular π-π inter-action occurs between the aromatic rings with a centroid-centroid distance of 3.9412 (9) Å.
In the title complex, [Cd(2)(NCS)(4)(C(13)H(19)N(3)O)(2)], the two Cd(II) ions are bridged by a pair of thio-cyanate N:S-bridging ligands around an inversion center. One terminal thio-cyanate N atom and one N,N',N''-tridentate Schiff base ligand complete a distorted CdN(5)S octa-hedral geometry about each Cd(II) atom. In the crystal, the Schiff base aromatic rings of adjacent mol-ecules are arranged above each other into infinite chains along the a axis with alternate centroid-centroid separations of 3.5299 (13) and 3.7857 (13) Å.
In the title compound, [Ni(NCS)(2)(C(11)H(17)N(3))(H(2)O)], the Ni(II) ion is six-coordinated by the N,N',N"-tridentate Schiff base N atoms, two cis-positioned N-bound isothio-cyanate groups and one water mol-ecule. In the crystal, O-H⋯S hydrogen bonds link adjacent mol-ecules into infinite layers parallel to the ac plane. The layers are further connected into a three-dimensional network via C-H⋯π inter-actions. The -CH(2)-N(CH(3))(2) fragment is disordered over two sets of sites in a 0.556 (5):0.444 (5) ratio.
In the title compound, [Mn(NCS)(2)(C(13)H(19)N(3)O)(H(2)O)], the Schiff base acts as an N,N',N"-tridentate ligand, forming two five-membered chelating rings with the Mn(II) atom. The distorted octa-hedral geometry around the metal atom is completed by two cis-positioned N-bound thio-cyanate ligands and one water mol-ecule. In the crystal, adjacent mol-ecules are linked through O-H⋯O, O-H⋯S and C-H⋯S hydrogen bonds into a three-dimensional supra-mol-ecular structure. An intra-molecular C-H⋯O hydrogen bond also occurs.