Synthesis, characterization, and anticancer activity of new quinazoline derivatives against MCF-7 cells

Two new synthesized and characterized quinazoline Schiff bases 1 and 2 were investigated for anticancer activity against MCF-7 human breast cancer cell line. Compounds 1 and 2 demonstrated a remarkable antiproliferative effect, with an IC50 value of 6.246×10(-6) mol/L and 5.910×10(-6) mol/L, respectively, after 72 hours of treatment. Most apoptosis morphological features in treated MCF-7 cells were observed by AO/PI staining. The results of cell cycle analysis indicate that compounds did not induce S and M phase arrest in cell after 24 hours of treatment. Furthermore, MCF-7 cells treated with 1 and 2 subjected to apoptosis death, as exhibited by perturbation of mitochondrial membrane potential and cytochrome c release as well as increase in ROS formation. We also found activation of caspases-3/7, -8, and -9 in compounds 1 and 2. Moreover, inhibition of NF-κB translocation in MCF-7 cells treated by compound 1 significantly exhibited the association of extrinsic apoptosis pathway. Acute toxicity results demonstrated the nontoxic nature of the compounds in mice. Our results showed significant activity towards MCF-7 cells via either intrinsic or extrinsic mitochondrial pathway and are potential candidate for further in vivo and clinical breast cancer studies.

Gastroprotection studies of Schiff base zinc (II) derivative complex against acute superficial hemorrhagic mucosal lesions in rats

Background

The study was carried out to assess the gastroprotective effect of the zinc (II) complex against ethanol-induced acute hemorrhagic lesions in rats.

Methodology/Principal Finding

The animals received their respective pre-treatments dissolved in tween 20 (5% v/v), orally. Ethanol (95% v/v) was orally administrated to induce superficial hemorrhagic mucosal lesions. Omeprazole (5.790×10⁻⁵ M/kg) was used as a reference medicine. The pre-treatment with the zinc (II) complex (2.181×10⁻⁵ and 4.362×10⁻⁵ M/kg) protected the gastric mucosa similar to the reference control. They significantly increased the activity levels of nitric oxide, catalase, superoxide dismutase, glutathione and prostaglandin E2, and decreased the level of malondialdehyde. The histology assessments confirmed the protection through remarkable reduction of mucosal lesions and increased the production of gastric mucosa. Immunohistochemistry and western blot analysis indicated that the complex might induced Hsp70 up-regulation and Bax down-regulation. The complex moderately increased the gastroprotectiveness in fine fettle. The acute toxicity approved the non-toxic characteristic of the complex (<87.241×10⁻⁵ M/kg).

Conclusion/Significance

The gastroprotective effect of the zinc (II) complex was mainly through its antioxidant activity, enzymatic stimulation of prostaglandins E2, and up-regulation of Hsp70. The gastric wall mucus was also a remarkable protective mechanism.

Acute toxicity and gastroprotection studies of a new schiff base derived copper (II) complex against ethanol-induced acute gastric lesions in rats

BACKGROUND

Copper is an essential element in various metabolisms. The investigation was carried out to evaluate acute gastroprotective effects of the Copper (II) complex against ethanol-induced superficial hemorrhagic mucosal lesions in rats.

METHODOLOGY/PRINCIPAL FINDINGS

Rats were divided into 7 groups. Groups 1 and 2 were orally administered with Tween 20 (10% v/v). Group 3 was orally administered with 20 mg/kg omeprazole (10% Tween 20). Groups 4-7 received 10, 20, 40, and 80 mg/kg of the complex (10% Tween 20), respectively. Tween 20 (10% v/v) was given orally to group 1 and absolute ethanol was given orally to groups 2-7, respectively. Rats were sacrificed after 1 h. Group 2 exhibited severe superficial hemorrhagic mucosal lesions. Gastric wall mucus was significantly preserved by the pre-treatment complex. The results showed a significant increase in glutathione (GSH), superoxide dismutase (SOD), nitric oxide (NO), and Prostaglandin E2 (PGE(2)) activities and a decrease in malondialdehyde (MDA) level. Histology showed marked reduction of hemorrhagic mucosal lesions in groups 4-7. Immunohistochemical staining showed up-regulation of Hsp70 and down-regulation of Bax proteins. PAS staining of groups 4-7 showed intense stain uptake of gastric mucosa. The acute toxicity revealed the non-toxic nature of the compound.

CONCLUSIONS/SIGNIFICANCE

The gastroprotective effect of the Copper (II) complex may possibly be due to preservation of gastric wall mucus; increase in PGE(2) synthesis; GSH, SOD, and NO up-regulation of Hsp70 protein; decrease in MDA level; and down-regulation of Bax protein.

Antibacterial evaluation of some Schiff bases derived from 2-acetylpyridine and their metal complexes

A series of Schiff bases derived from 2-acetylpyridne and their metal complexes were characterized by elemental analysis, NMR, FT-IR and UV-Vis spectral studies. The complexes were screened for anti-bacterial activity against Methicillin-resistant Staphylococcus aureus (MRSA), Acinetobacter baumanni (AC), Klebsiella pneumonie (KB) and Pseudomonas aeruginosa (PA) using the disc diffusion and micro broth dilution assays. Based on the overall results, the complexes showed the highest activities against MRSA while a weak antibacterial activity was observed against A. baumanii and P. aeruginosa.

Synthesis, characterization, X-ray crystallography, acetyl cholinesterase inhibition and antioxidant activities of some novel ketone derivatives of gallic hydrazide-derived Schiff bases

Alzheimer's disease (AD) is the most common form of dementia among older people and the pathogenesis of this disease is associated with oxidative stress. Acetylcholinesterase inhibitors with antioxidant activities are considered potential treatments for AD. Some novel ketone derivatives of gallic hydrazide-derived Schiff bases were synthesized and examined for their antioxidant activities and in vitro and in silico acetyl cholinesterase inhibition. The compounds were characterized using spectroscopy and X-ray crystallography. The ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays revealed that all the compounds have strong antioxidant activities. N-(1-(5-bromo-2-hydroxyphenyl)-ethylidene)-3,4,5-trihydroxybenzohydrazide (2) was the most potent inhibitor of human acetyl cholinesterase, giving an inhibition rate of 77% at 100 μM. Molecular docking simulation of the ligand-enzyme complex suggested that the ligand may be positioned in the enzyme's active-site gorge, interacting with residues in the peripheral anionic subsite (PAS) and acyl binding pocket (ABP). The current work warrants further preclinical studies to assess the potential for these novel compounds for the treatment of AD.

Dichlorido{N,N-dimethyl-N'-[1-(2-pyrid-yl)ethyl-idene]ethane-1,2-diamine-κN,N',N''}zinc

The asymmetric unit of the title compound, [ZnCl₂(C₁₁H₁₇N₃)], contains two independent penta­coordinate Zn^II complex mol­ecules. In each mol­ecule, 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 mol­ecules differ little in their geometry, but more in their inter­molecular inter­actions. In the crystal, adjacent mol­ecules are connected via C—H⋯Cl inter­actions into a three-dimensional supra­molecular structure. The network is supplemented by π–π inter­actions formed between the aromatic rings of pairs of the symmetry-related mol­ecules [centroid–centroid distances = 3.6255 (10) and 3.7073 (10) Å]. The crystal lattice contains void spaces with a size of 52 ų.

Hexachloridobis-{μ-2-(piperazin-1-yl)-N-[1-(2-pyrid-yl)ethyl-idene]ethanamine}-trizinc dihydrate

In the trinuclear title compound, [Zn₃Cl₆(C₁₃H₂₀N₄)₂]·2H₂O, each terminal Zn^II atom is coordinated by an N₃ donor set from the Schiff base ligands and two Cl atoms in a distorted square-pyramidal geometry. The central Zn^II atom is tetra­hedrally 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 mol­ecules 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 mol­ecules, one of which is disordered over two positions with occupancies of 0.753 (15) and 0.247 (15).

Aqua{2-(morpholin-4-yl)-N-[1-(2-pyri-dyl)ethyl-idene]ethanamine-κN,N',N''}bis-(thio-cyanato-κN)manganese(II)

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.

{N,N-Dimethyl-N'-[1-(2-pyrid-yl)ethyl-idene]ethane-1,2-diamine-κN,N',N''}bis-(thio-cyanato-κN)copper(II)

The asymmetric unit of the title compound, [Cu(NCS)₂(C₁₁H₁₇N₃)], consists of two crystallographically independent mol­ecules. In each mol­ecule, 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 thio­cyanate ligand. The second N-donor thio­cyanate group, located at the apical site, completes the coordination environment. In the crystal, inter­molecular C—H⋯S and C—H⋯N hydrogen bonds link adjacent mol­ecules into infinite layers parallel to the ac plane. Intra­molecular C—H⋯N inter­actions are also observed.

Bis(μ-2-{1-[2-(dimethyl-amino)-ethyl-imino]-eth-yl}phenolato)bis-[bromido-copper(II)] monohydrate

In the centrosymmetric dinuclear copper(II) title complex, [Cu₂Br₂(C₁₂H₁₇N₂O)₂]·H₂O, 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 mol­ecules link the complex mol­ecules into infinite chains along the b axis via O—H⋯Br and C—H⋯O hydrogen bonds.

Diiodido{2-(morpholin-4-yl)-N-[1-(2-pyrid-yl)ethyl-idene]ethanamine-κN,N',N''}zinc

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.

Aqua-{N,N-dimethyl-N'-[1-(2-pyrid-yl)ethyl-idene]ethane-1,2-diamine-κN,N',N''}bis-(thio-cyanato-κN)nickel(II)

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.

catena-Poly[[{N,N-dimethyl-N'-[1-(pyridin-2-yl)ethyl-idene]ethane-1,2-diamine-κN,N',N''}(thio-cyanato-κN)cadmium]-μ-thio-cyanato-κS:N]

In the title compound, [Cd(NCS)₂(C₁₁H₁₇N₃)]_n, the Cd^II atom is octa­hedrally coordinated by the N,N′,N′′-tridentate Schiff base ligand and one terminal thio­cyanate N atom. Two trans-N:S-bridging thio­cyanates complete the N₅S donor set around the Cd atom. In the crystal, adjacent Cd^II ions are linked by the thio­cyanate N:S-bridges into polymeric chains along the c axis.

Dichloridobis[2-(morpholin-4-yl)ethanamine-κ2N,N′]cadmium

In the title compound, [CdCl₂(C₆H₁₄N₂O)₂], the Cl and Cd^II atoms are located on a twofold rotation axis and the Cd^II atom is octa­hedrally coordinated by two N,N′-bidentate 2-(morpholin-4-yl)ethanamine ligands and two trans-located Cl atoms. In the crystal, adjacent mol­ecules are linked by N—H⋯Cl and C—H⋯O hydrogen bonds into a three-dimensional structure. An intra­molecular C—H⋯Cl hydrogen bond is also observed.

Dibromido{2-(morpholin-4-yl)-N-[1-(2-pyrid-yl)ethyl-idene]ethanamine-κN,N',N''}cadmium

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.

Dichlorido{N,N-dimethyl-N'-[1-(pyridin-2-yl)ethyl-idene]ethane-1,2-diamine-κN,N',N''}cadmium

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.

Dichlorido{2-(morpholin-4-yl)-N-[1-(pyridin-2-yl)ethyl-idene]ethanamine-κN,N',N''}copper(II) monohydrate

In the title compound, [CuCl₂(C₁₃H₁₉N₃O)]·H₂O, 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 mol­ecules and the uncoordinated water mol­ecules 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 inter­actions.

Di-μ-thio-cyanato-κN:S;κS:N-bis-({2-morpholino-N-[1-(2-pyrid-yl)ethyl-idene]ethanamine-κN,N',N''}(thio-cyanato-κN)cadmium)

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.

Dichlorido{N,N-dimethyl-N'-[1-(2-pyrid-yl)ethyl-idene]ethane-1,2-diamine-κN,N',N''}manganese(II)

The asymmetric unit of the title compound, [MnCl(2)(C(11)H(17)N(3))], contains two crystallographically independent mol-ecules with slightly different geometries. In each mol-ecule, the Mn(II) ion is five coordinated by the N,N',N''-tridentate Schiff base and two Cl atoms in a distorted square-pyramidal geometry. In the crystal, C-H⋯Cl hydrogen bonds link adjacent mol-ecules into a three-dimensional network.

Aqua-{2-morpholino-N-[1-(2-pyrid-yl)ethyl-idene]ethanamine-κN,N',N''}bis-(thio-cyanato-κN)cobalt(II)

In the title complex, [Co(NCS)(2)(C(13)H(19)N(3)O)(H(2)O)], the Co(II) ion is six-coordinated by the N,N',N''-tridentate Schiff base, the N atoms of two thio-cyanate ligands and one water mol-ecule in a distorted octa-hedral geometry. Intra-molecular C-H⋯N and C-H⋯O hydrogen bonds occur. In the crystal, inter-molecular O-H⋯O, O-H⋯S, C-H⋯S and S⋯S [3.5546 (18) Å] inter-actions result in an infinite three-dimensional network.

{2-Morpholino-N-[1-(2-pyridyl)ethylidene]ethanamine-κ3N,N′,N′′}bis(thiocyanato-κN)copper(II)

In the title compound, [Cu(NCS)₂(C₁₃H₁₉N₃O)], the Cu^II ion is five-coordinated by the N,N′,N′′-tridentate Schiff base and the N atoms of two isothio­cyanate ligands in a square-pyramidal geometry. In the crystal, C—H⋯N, C—H⋯O and C—H⋯S inter­actions link adjacent mol­ecules into layers parallel to the ac plane. A weak inter­molecular π–π inter­action occurs between the aromatic rings with a centroid–centroid distance of 3.9412 (9) Å.

{2-Morpholino-N-[1-(2-pyrid-yl)ethyl-idene]ethanamine-κN,N',N''}bis-(thio-cyanato-κN)zinc(II)

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.

Two new polymorphs of 2,6-diaminopyrimidin-4(3H)-one monohydrate

The title compound, C(4)H(6)N(4)O·H(2)O, crystallized simultaneously as a triclinic and a monoclinic polymorph from an aqueous solution of 2,4-diaminopyrimidin-6-ol. Previously, an orthorhombic polymorph was isolated under the same experimental conditions. The molecular geometric parameters in the two present polymorphs and the previously reported orthorhombic polymorph are similar, but the structures differ in the details of their crystal packing. In the triclinic system, the diaminopyrimidinone molecules are connected to one another via N-H···O and N-H···N hydrogen bonding to form infinite chains in the [011] direction. The chains are further hydrogen bonded to the water molecules, resulting in a three-dimensional network. In the monoclinic system, the diaminopyrimidinone molecules are hydrogen bonded together into two-dimensional networks parallel to the bc plane. The water molecules link the planes to form a three-dimensional polymeric structure.

Aqua-{2-morpholino-N-[1-(2-pyrid-yl)ethyl-idene]ethanamine-κN,N',N''}bis-(thio-cyanato-κN)nickel(II)

In the title compound, [Ni(NCS)(2)(C(13)H(19)N(3)O)(H(2)O)], the Ni(II) ion is six-coordinated by the N,N',N''-tridentate Schiff base, the N atoms of two thio-cyanate ligands and one water O atom in a distorted octa-hedral geometry. Intra-molecular C-H⋯N and C-H⋯O hydrogen bonds occur. In the crystal, O-H⋯S, O-H⋯O and C-H⋯S hydrogen bonds link adjacent mol-ecules into layers parallel to the ac plane.

Chlorido(2-{1-[(2-morpholino-eth-yl)imino]-eth-yl}phenolato-κN,N',O)copper(II)

In the title compound, [CuCl(C₁₄H₁₉N₂O₂)], the Cu^II ion is four-coordinated by one deprotonated N,N′,O-tridentate Schiff base and one chloride ion in a distorted square-planar geometry. In the crystal, adjacent mol­ecules are linked via C—H⋯Cl and C—H⋯O inter­actions, forming infinite layers parallel to the (100) plane. The structure was determined from a non-merohedrally twined crystal [twin ratio 0.777 (3):0.223 (3)].

Dichlorido{2-morpholino-N-[1-(2-pyrid-yl)ethyl-idene]ethanamine-κN,N',N''}zinc(II)

In the title compound, [ZnCl₂(C₁₃H₁₉N₃O)], the Schiff base ligand acts as an N,N′,N′′-tridentate chelating agent, making two five-membered rings with the Zn^II ion. The metal atom is five-coordinated by the Schiff base ligand and two Cl atoms in a distorted square-pyramidal geometry. An intra­molecular C—H⋯Cl inter­action occurs. In the crystal, adjacent mol­ecules are linked together via C—H⋯Cl hydrogen-bonding and long range C—H⋯O and C—H⋯Cl inter­actions into a three-dimensional network.

Dichlorido{2-morpholino-N-[1-(2-pyrid-yl)ethyl-idene]ethanamine-κN,N',N''}manganese(II)

In the title compound, [MnCl₂(C₁₃H₁₉N₃O)], the Mn^II ion is penta­coordinated in a distorted square-pyramidal geometry. The coordination environment is defined by the N,N′,N′′-tridentate Schiff base ligand and one Cl atom in the basal positions and one Cl atom in the apical position. In the crystal, inter­molecular C—H⋯Cl hydrogen bonds link the mol­ecules into a three-dimensional network. An intra­molecular C—H⋯Cl hydrogen bond is also observed.

Dichlorido{2-morpholino-N-[1-(2-pyri-dyl)ethyl-idene]ethanamine-κN,N',N''}cadmium

In the title compound, [CdCl₂(C₁₃H₁₉N₃O)], the Cd^II ion is five-coordinate, with the N,N′,N′′-tridentate Schiff base ligand 2-morpholino-N-[1-(2-pyrid­yl)ethyl­idene]ethanamine and two Cl atoms in a distorted square-pyramidal geometry. In the crystal structure, C—H⋯Cl hydrogen-bonding inter­actions connect the mol­ecules into a three-dimensional network.

2,6-Diamino-4-oxo-3,4-dihydropyrim-idin-1-ium chloride dihydrate

In the crystal structure of the title compound, C(4)H(7)N(4)O(+)·Cl(-)·2H(2)O, adjacent cations are connected to one another through N-H⋯O hydrogen bonds, forming infinite chains along the b axis. These chains are further hydrogen bonded to the chloride anions and water mol-ecules, resulting in a three-dimensional network. The pyrimidine rings of adjacent mol-ecules are arranged in an anti-parallel manner above each other with centroid-centroid distances of 3.435 (1) Å, indicative of π-π inter-actions.

[(1S,2S)-2-(1-{[2-(2-Oxidobenzyl-idene-amino)-cyclo-hex-yl]imino}-eth-yl)phenolato-κO,N,N',O']copper(II)

In the title compound, [Cu(C₂₁H₂₂N₂O₂)], the cyclo­hexyl 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, inter­molecular C—H⋯O inter­actions are present and stabilize the structure.

N'-[1-(5-Bromo-2-hydroxy-phen-yl)ethyl-idene]-3,4,5-trihydroxy-benzohydrazide dimethyl sulfoxide solvate trihydrate

The benzohydrazide mol­ecule in the title compound, C₁₅H₁₃BrN₂O₅·C₂H₆OS·3H₂O, is almost planar with an r.m.s. deviation for the non-H atoms of 0.078 Å. The organic mol­ecules, water and dimethyl sulfoxide solvent mol­ecules are linked by N—H⋯O, O—H⋯O and O—H⋯S inter­molecular hydrogen bonds, forming zigzag chains along the a axis. Intra­molecular O—H⋯O and O—H⋯N hydrogen bonds also occur.