Syntheses, Crystal Structures and Antimicrobial Activity of Copper(II) Complexes with the Ligand N,N'-Bis(4-bromosalicylidene)propane-1,2-diamine.

Three new copper(II) complexes, [CuClL] (1), [CuBrL]n (2) and [CuL(NCS)]n (3), derived from the Schiff base 2,4-dichloro-6-((2-pyrrolidin-1-ylethylimino)methyl)phenol (HL) have been prepared and characterized by spectroscopy methods, as well as single crystal X-ray determination. The Cu atom in complex 1 is in square planar coordination, and those in complexes 2 and 3 are in square pyramidal coordination. The Schiff base ligand coordinates to the Cu atoms through phenolate oxygen, imino nitrogen and pyrrolidine nitrogen. The antibacterial activities of the Schiff base and the three copper complexes have been assayed on the bacteria Staphylococcus aureus and Escherichia coli, and the yeast Candida parapsilosis.

Human Placenta-Derived Mesenchymal Stem Cells Improve Neurological Function in Rats with Intrauterine Hypoxic-Ischaemic Encephalopathy by Reducing Apoptosis and Inflammatory Reactions.

BACKGROUND: Hypoxic-ischaemic encephalopathy (HIE) is a major cause of neonatal disability and mortality. Although hypothermia therapy offers some neuroprotection, the recovery of neurological function is limited. Therefore, new synergistic therapies are necessary to improve the prognosis. Mesenchymal stem cell-based therapy is emerging as a promising treatment option for HIE. In this study, we studied the therapeutic efficacy of human placenta-derived mesenchymal stem cells (PD-MSCs) in the HIE rat model and analyzed the underlying therapeutic mechanisms. METHODS: Rats were divided into 6 groups (n = 9 for each) as follows: control, HIE model, HIE + normal saline, and HIE + PD-MSC transplantation at days 7, 14 and 28 postpartum. Following PD-MSC transplantation, neurological behavior was evaluated using rotarod tests, traction tests, and the Morris water maze test. The degree of brain tissue damage was assessed by histological examination and Nissl staining. Expression levels of apoptosis-related proteins and inflammatory factors were quantified by Western blotting and enzyme-linked immunosorbent assays. Immunofluorescence was used to investigate the ability of PD-MSCs to repair the morphology and function of hippocampal neurons with hypoxic-ischaemic (HI) injury. RESULTS: PD-MSC transplantation enhanced motor coordination and muscle strength in HIE rats. This treatment also improved spatial memory ability by repairing pathological damage and preventing the loss of neurons in the cerebral cortex. The most effective treatment was observed in the HIE + PD-MSC transplantation at day 7 group. Expression levels of microtubule-associated protein-2 (MAP-2), B-cell lymphoma-2 (BCL-2), interleukin (IL)-10, and transforming growth factor (TGF -ß1) were significantly higher in the HIE + PD-MSC treatment groups compared to the HIE group, whereas the levels of BCL-2-associated X protein (BAX), BCL-2-associated agonist of cell death (BAD), IL-1ß and tumour necrosis factor α (TNF-α) were significantly lower. CONCLUSIONS: We demonstrated that intravenous injection of PD-MSC at 7, 14 and 28 days after intrauterine HI damage in a rat model could improve learning, memory, and motor function, possibly by inhibiting apoptosis and inflammatory damage. These findings indicate that autologous PD-MSC therapy could have potential application for the treatment of HIE.

(E)-N'-[(2-Hydroxynaphthalen-1-yl)methylidene]nicotinohydrazide.

In the mol-ecule of the title compound, C(17)H(13)N(3)O(2), the naphthyl ring system and the pyridine ring form a dihedral angle of 12.2 (3)°. An intra-molecular O-H⋯N hydrogen bond generates a six-membered ring with an S(6) ring motif. This also contributes to the relative overall near planarity of the mol-ecule [r.m.s. deviation of all 22 non-H atoms = 0.107 (5) Å]. In the crystal, mol-ecules are linked through inter-molecular N-H⋯N hydrogen bonds, forming chains along the a axis.

Copper(II) and Zinc(II) Complexes Derived from N,N'-Bis(4-bromosalicylidene)propane-1,3-diamine: Syntheses, Crystal Structures and Antimicrobial Activity.

A mononuclear copper(II) complex, [CuL] (1), and a phenolato-bridged trinuclear zinc(II) complex, [Zn3Cl2L2(DMF)2] (2), where L is the deprotonated form of N,N'-bis(4-bromosalicylidene)propane-1,3-diamine (H2L), have been prepared and characterized by elemental analyses, IR and UV-Vis spectroscopy, and single crystal X-ray diffraction. The Cu atom in complex 1 is in square planar coordination, while the terminal and central Zn atoms in complex 2 are in square pyramidal and octahedral coordination, respectively. The antibacterial activities of the complexes have been tested on the bacteria Staphylococcus aureus and Escherichia coli, and the yeast Candida parapsilosis.

N'-[(2-Hydr-oxy-1-naphth-yl)methyl-idene]-2-nitro-benzohydrazide.

In the title Schiff base compound, C(18)H(13)N(3)O(4), prepared by the reaction of 2-hydr-oxy-1-naphthaldehyde with 2-nitro-benzohydrazide, the dihedral angle between the benzene ring and naphthyl ring system is 23.0 (2)°. There is an intra-molecular O-H⋯N hydrogen bond involving the naphthalene hydr-oxy substituent and a hydrazide N atom. In the crystal structure, symmetry-related mol-ecules are linked through inter-molecular N-H⋯O hydrogen bonds, forming chains propagating in [101].

2-Chloro-5-nitro-benzaldehyde thio-semicarbazone.

The title Schiff base compound, C(8)H(7)ClN(4)O(2)S, was prepared by the reaction of equimolar quanti-ties of 2-chloro-5-nitro-benzaldehyde with thio-semicarbazide in methanol. The mol-ecule adopts a trans configuration with respect to the azomethine group and the dihedral angle between the benzene ring and the thio-semicarbazide group is 6.8 (3)°. In the crystal, mol-ecules are linked through inter-molecular N-H⋯S hydrogen bonds, forming chains propagating in [010].

N'-(5-Chloro-2-hy-droxy-benzyl-idene)-2-meth-oxy-benzohydrazide.

The title Schiff base compound, C(15)H(13)ClN(2)O(3), was prepared by the reaction of equimolar quanti-ties of 5-chloro-2-hy-droxy-benzaldehyde with 2-meth-oxy-benzohydrazide in a methanol solution. The dihedral angle between the two benzene rings is 20.6 (3)°. An intra-molecular O-H⋯N hydrogen bond may influence the mol-ecular conformation. In the crystal structure, mol-ecules form chains along the b direction via inter-molecular N-H⋯O hydrogen bonds which are bifurcated involving an intra-molecular N-H⋯O hydrogen bond.

2-Hy-droxy-4-meth-oxy-benzaldehyde thio-semicarbazone.

The title Schiff base compound, C(9)H(11)N(3)O(2)S, was prepared by the reaction of equimolar quanti-ties of 2-hy-droxy-4-meth-oxy-benzaldehyde with thio-semicarbazide in methanol. The mol-ecule adopts a trans configuration with respect to the azo-methine group and an intra-molecular O-H⋯N hydrogen bond generates an S(6) ring. In the crystal structure, mol-ecules are linked through inter-molecular N-H⋯O and N-H⋯S hydrogen bonds, forming a three-dimensional network.

3-Hydr-oxy-N'-(2-methoxy-benzyl-idene)-2-naphthohydrazide.

In the title Schiff base compound, C(19)H(16)N(2)O(3), the dihedral angle between the mean planes of the benzene ring and the naphthyl ring system is 0.8 (2)°. The mean plane of the hydrazide group forms dihedral angles of 2.0 (2) and 2.2 (2)°, respectively, with the mean planes of the benzene ring and the naphthyl ring system. A strong intra-molecular N-H⋯O hydrogen bond is present. In the crystal, inter-molecular O-H⋯O hydrogen bonds form chains along the c axis and help to provide stability in the crystal packing.

1-[(2-Anilinoeth-yl)iminiometh-yl]-2-naph-thol-ate.

The title Schiff base compound, C(19)H(18)N(2)O, was prepared by the reaction of equimolar quanti-ties of 2-hydr-oxy-1-naphthaldehyde with N-phenyl-ethane-1,2-diamine in a methanol solution. The mol-ecule adopts a zwitterionic conformation with the naphthyl OH group deprotonated and the imine N atom protonated. An intra-molecular N-H⋯O hydrogen bond forms between them. The dihedral angle between the benzene ring and the naphthyl system is 86.9 (2)°. In the crystal structure, mol-ecules are linked through inter-molecular N-H⋯O hydrogen bonds, forming chains running along the b axis.

N'-(2-Chloro-benzyl-idene)-4-hydroxy-benzohydrazide.

In the mol-ecule of the title compound, C(14)H(11)ClN(2)O(2), the dihedral angle between the benzene rings is 30.53 (4)°. In the crystal structure, inter-molecular O-H⋯O and N-H⋯O hydrogen bonds link the mol-ecules into a two-dimensional network. π-π contacts between benzene rings [centroid-centroid distance = 3.619 (1) Å] may further stabilize the structure. The crystal studied was found to be an inversion twin.

2-Bromo-4-chloro-6-(cyclo-pentyl-imino-meth-yl)phenol.

All atoms of the title mol-ecule, C(12)H(13)BrClNO, except the C and H atoms of the cyclo-pentane methyl-ene groups lie on a crystallographic mirror plane. The cyclo-pentane ring adopts an envelope conformation and an intra-molecular O-H⋯N hydrogen bond is observed. In the crystal, mol-ecules are stacked along the b axis by π-π inter-actions [centroid-centroid distance = 3.6424 (11) Å].