Hydrophilic bis-MPA hyperbranched dendritic scaffolds as nanocarriers of a fully characterized flavonoid morin-Zn(II) complex for anticancer applications.

In this work the first crystallographically characterized complex of the bioactive flavonoid morin with the Zn(II) ion is presented along with its complete physico-chemical characterization. In view of the antioxidant activity of morin and its toxicity against respiratory tract cancers, the encapsulation of the complex in the hydrophilic bis(methylol)propionic acid hyperbranched dendritic scaffolds (bis-MPA HDSs) was effected. The produced nano-formulations were characterized with physico-chemical and electron microscopy techniques, and biologically evaluated for their antioxidant and anticancer activity against human A549 and H520 lung cancer cells, as well as healthy human MRC-5 lung fibroblasts. The obtained results demonstrate that encapsulation increases the solubility, and thus bioavailability, of the complex in physiological media and enhances anticancer action. They also highlight the importance of the non-toxic bis-MPA HDSs as nanocarriers of bioactive flavonoid metal complexes for anticancer therapeutic applications.

Crystal structure of fac-aqua-[(E)-4-(benzo[d]thia-zol-2-yl)-N-(pyridin-2-yl-methyl-idene)aniline-κ2 N,N']tricarbonylrhenium(I) hexa-fluorido-phosphate methanol monosolvate.

In the title compound, fac-[Re(C19H13N3S)(CO)3(H2O)]PF6·CH3OH, the coordination environment of the ReI atom is octa-hedral with a C3N2O coordination set. In this mol-ecule, the N,N' bidentate ligand, (E)-4-(benzo[d]thia-zol-2-yl)-N-(pyridin-2-yl-methyl-idene)aniline, and the monodentate aqua ligand occupy the three available coordination sites of the [Re(CO)3]+ core, generating a '2 + 1' mixed-ligand complex. In this complex, the Re-C bonds of the carbonyl ligands trans to the coordinating N,N' atoms of the bidentate ligand are longer than the Re-C bond of the carbonyl group trans to the aqua ligand, in accordance with the intensity of their trans effects. The complex is positively charged with PF6 - as the counter-ion. In the structure, the complexes form dimers through π-π inter-molecular inter-actions. O-H⋯O and O-H⋯N hydrogen bonds lead to the formation of stacks parallel to the a axis, which further extend into layers parallel to (01). Through O-H⋯F hydrogen bonds between the complexes and the PF6 -counter-anions, a three-dimensional network is established.

Re(I) tricarbonyl complex of 1,10-phenanthroline-5,6-dione: DNA binding, cytotoxicity, anti-inflammatory and anti-coagulant effects towards platelet activating factor.

The complex fac-[Re(CO)3(phendione)Cl] (1) (where phendione=1,10-phenanthroline-5,6-dione) has been synthesized and fully characterized by UV-visible, FTIR, and NMR techniques. The DNA binding properties of 1 are investigated by UV-spectrophotometric (melting curves), covalent binding assay, CV (cyclic voltammetry), circular dichroism (CD) and viscosity measurements. Experimental data indicate that 1 fits into the major groove without disrupting the helical structure of the B-DNA in contrast to the free phendione which intercalates within the base pairs of DNA. Upon irradiation, complex 1 promotes the cleavage of plasmid pBR322 DNA from supercoiled form I to nicked form II via a proton coupled electron transfer mechanism. This comes as a result of experimental data in anaerobic/aerobic conditions and in the presence of DMSO. The biological activities of 1 and its precursors [Re(CO)5Cl] and phendione are tested towards a series of cancerous cell lines as glioblastoma (T98G), prostate cancer (PC3) and breast cancer (MCF-7) as well as platelet activating factor (PAF)-aggregation. Moreover, all the aforementioned compounds are tested for their ability to modulate PAF-basic metabolic enzyme activities in preparations of rabbit leukolytes. The in vitro experiments indicate that phendione has a better antitumor effect than cisplatin whereas [Re(CO)5Cl] is a better PAF inhibitor than both the phendione ligand and 1. Moreover, for the first time it is indicated that [Re(CO)5Cl], with a IC50 of 17nM is comparable to the widely used PAF receptor antagonists, BN52021 and WEB2170 with IC50 of 30 and 20nM, respectively, whereas 1 affects PAF-catabolism.