Combining valproate and bipyridyl ligands to construct a 0D core-shell Zn5(µ3-OH)2 cluster and a 2D layered coordination network with a [Zn3(µ3-OH)]2 SBU.

Starting from the proposed zinc carboxylate cluster tetrakis(µ-2-propylpentanoato)dizinc(II), Zn2(µ2-valp)4 (I), of valproic acid, a branched short-chain fatty acid, and bipyridine ligands, two new mixed-ligand coordination compounds, namely, bis(2,2'-bipyridine)di-µ3-hydroxido-hexakis(µ-2-propylpentanoato)bis(2-propylpentanoato)pentazinc(II), [Zn5(C8H15O2)8(OH)2(C10H8N2)2] (II), and poly[[bis(µ-4,4'-bipyridine)di-µ3-hydroxido-octakis(µ-2-propylpentanoato)bis(2-propylpentanoato)hexazinc(II)] dimethylformamide disolvate], {[Zn6(C8H15O2)10(OH)2(C10H8N2)2]·2C3H7NO}n (III), were synthesized. Compound II is a core-shell-type zero-dimensional discrete Zn5(µ3-OH)2 metal-organic cluster with Zn ions in double-triangle arrangements that share one Zn ion coincident with an inversion centre. The cluster contains three crystallographically non-equivalent Zn ions exhibiting three different coordination geometries (tetrahedral, square pyramidal and octahedral). The cluster cores are well separated and embedded in a protective shell of the aliphatic branched short chains of valproate. As a result, there is no specific interaction between the discrete clusters. Conversely, compound III, a 2D layered coordination network with a secondary building unit (SBU), is formed by Zn6(µ3-OH)2 clusters exhibiting a chair-like hexagonal arrangement. This SBU is formed from two Zn3(µ3-OH) trimers related by inversion symmetry and connected by two syn-anti bridging carboxylate groups. Each SBU is connected by four 4,4'-bipyridine ligands producing a 63-hcb net topology. 2D coordination layers are sandwiched within layers of dimethylformamide molecules that do not interact strongly with the network due to the hydrophobic protection provided by the valproate ligands.

Acylated Flavone O-Glucuronides from the Aerial Parts of Nepeta curviflora.

Nepeta curviflora Boiss. (Syrian catnip) is native to the Middle East. This medicinal plant is commonly used against nervous disorders, rheumatic pains, and high blood pressure. Herbal infusions prepared from various Nepeta spp. are extensively consumed as functional food. However, limited information has been known about the phenolic constituents of Syrian catnip. In this study, two acylated flavone 7-O-glucuronides, apigenin 7-O-(2″-O-(2‴-(E-caffeoyl)-ß-glucuronopyranosyl)-ß-glucuronopyranoside) (1) and luteolin 7-O-(2″-O-(2‴-(E-caffeoyl)-ß-glucuronopyranosyl)-ß-glucuronopyranoside) (2), along with the known phenolic compounds rosmarinic acid, caffeic acid, apigenin, and apigenin 7-O-ß-glucopyranoside were isolated from the aerial parts of N. curviflora. The characterizations of these compounds were based on high-resolution mass spectrometry, UV, and extensive use of multidimensional NMR spectroscopy. The new compounds (1 and 2) were identified in the unmodified state and as dimethylesters.

Synthesis, crystallographic, spectroscopic studies and biological activity of new cobalt(II) complexes with bioactive mixed sulindac and nitrogen-donor ligands.

Four novel complexes [Co(H2O)4(sul)2] 1, [Co(2-ampy)2(sul)2] 2, [Co(H2O)2(1,10-phen) (sul)2] 3 and [Co(2,9-dimephen)(sul)2] 4 (sul = sulindac, 2-ampy = 2-amino pyridine, 1,10-phen = 1,10-phenanthroline and 2,9-dimeph = 2,9-dimethyl-1,10-phenanthroline) were prepared and characterized by IR, UV-Visible spectroscopy and magnetic properties. The crystal structures of complexes 1 and 4 were determined by single-crystal X-ray diffraction. In-vitro anti-bacterial activity for the prepared complexes against Gram-positive (Staphylococcus epidermidis, Staphylococcus aureus) and Gram-negative (Bordetella, Escherichia coli) bacteria and Yeast species (Saccharomyces and Candida) were performed using agar well-diffusion method. Only complex 4 showed reasonable activity against yeast. All compounds showed more anti-bacterial activity against Gram-positive bacteria than Gram-negative. Graphical abstract This work reports synthesis, crystallographic, spectroscopic studies and biological activity of new cobalt(II) complexes with bioactive mixed sulindac and nitrogen-donor ligands. The crystal structures of complexes 1 and 4 were determined using single-crystal X-ray diffraction. In-vitro anti-bacterial activity of the prepared complexes and their parent ligands were investigated against different Gram-positive and Gram-negative bacteria using agar diffusion method.

Synthesis, characterization and biological activity of new mixed ligand complexes of Zn(II) naproxen with nitrogen based ligands.

A series of novel Zn(II) complexes [Zn2(nap)4] (1), [Zn(nap)21,10-phen](2), [Zn(nap)22,9-dmphen] (3), [Zn(nap)2(2-ampy)2] (4), [Zn(nap)2(imid)2] (5), [Zn(nap)2(1,2-dmimid)2] (6) (nap = naproxen, 1,10-phen = 1,10-phenanthroline, 2,9-dmphen = 2,9-dimethyl-1,10-phenanthroline, 2-ampy = 2-aminopyridine, imid = imidazole, 1,2-dmimid = 1,2-dimethyl imidazole) were synthesized and characterized using IR, UV-Vis, (1)H NMR, (13)C{(1)H} NMR spectroscopy. The crystal structure of complex 3 was determined using single-crystal X-ray diffraction. In order to assess the effect of the metal ions on the anti-bacterial activity, complexes 1-6 have been screened in vitro, against (G(+)) bacteria (Staphylococcus aureus and Micrococcus luteus) and (G(-)) bacteria (Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis and Escherichia coli) using the agar well diffusion method. Complex 2 was the only complex that showed antibacterial activity against P. aeruginosa, where the complexation of the parent ligand 1,10-phenathroline enhanced significantly the activity. All the complexes showed different activity against the different bacteria, and were compared with activity of the parent ligands. The complexes were tested also for their anti-malarial activity using two methods: a semi-quantitative micro-assay and a previously self-developed quantitative in-vitro method. Both were used to study the efficiency of these complexes in inhibiting the formation of the Malaria pigment. This is considered an important target of many known anti-malarial drugs such as Chloroquine and Amodaquine. Results showed that the efficiency of complex 3 in preventing the formation of ß-hematin was 75%. The efficiency of Amodiaquine as a standard drug was reported to give 92.5.

New mixed ligand zinc(II) complexes based on the antiepileptic drug sodium valproate and bioactive nitrogen-donor ligands. Synthesis, structure and biological properties.

Starting from the precursor [Zinc Valproate complex] (1), new mixed ligand zinc(II) complexes of valproic acid and nitrogen-based ligands, formulating as, [Zn(valp)22,9-dmphen] (2), [Zn2(valp)4(quin)2] (3), [Zn(valp)2(2-ampy)2] (4), and [Zn(valp)2(2-ampic)2] (5) (valp = valproate, 2,9-dmphen = 2,9-dimethyl-1,10-phenanthroline, quin = quinoline, 2-ampy = 2-aminopyridine, 2-ampic = 2-amino-6-picoline) were synthesized and characterized using IR, (1)H NMR, (13)C{(1)H} NMR and UV-Vis spectrometry. The crystal structures of complexes 2, 3 and 4 were determined using single-crystal X-ray diffraction. The complexes were also evaluated for their anti-bacterial activity using in-vitro agar diffusion method against three Gram-positive (Micrococcus luteus, Staphylococcus aureus, and Bacillus subtilis) and three Gram-negative (Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis) species. Complex 2 showed considerable activity against all tested microorganisms and the effect of complexation on the anti-bacterial activity of the parent ligand of 2 was also investigated. The anti-bacterial activity of 2,9-dmphen against Gram-negative bacteria was enhanced upon complexation with zinc valproate. On the other hand, complexes 1 and 3 showed weak inhibition activity against the tested species and complexes 4 and 5 didn't show any activity at all. Two methods were used for testing the inhibition of ferriprotoporphyrinIX bio-mineralization: a semi-quantitative micro-assay and a previously self-developed quantitative in-vitro method. Both were used to study the efficiency of these complexes in inhibiting the formation of the Malaria pigment which considered being the target of many known anti-malarial drugs such as Chloroquine and Amodiaquine. Results showed that the efficiency of complex 2 in preventing the formation of ß-Hematin was 80%. The efficiency of Amodiaquine as a standard drug was reported to give 91%.