Ruthenium(II)/(III) complexes of 4-hydroxy-pyridine-2,6-dicarboxylic acid with PPh3/AsPh3 as co-ligand: impact of oxidation state and co-ligands on anticancer activity in vitro.

With the aim to develop more efficient, less toxic, target specific metal drugs and evaluate their anticancer properties in terms of oxidation state and co-ligand sphere, a sequence of Ru(II), Ru(III) complexes bearing 4-hydroxy-pyridine-2,6-dicarboxylic acid and PPh(3)/AsPh(3) were synthesized and structurally characterized. Biological studies such as DNA binding, antioxidant assays and cytotoxic activity were carried out and their anticancer activities were evaluated. Interactions of the complexes with calf thymus DNA revealed that the triphenylphosphine complexes could bind more strongly than the triphenylarsine complexes. The free radical scavenging ability, assessed by a series of in vitro antioxidant assays involving DPPH radical, hydroxyl radical, nitric oxide radical, superoxide anion radical, hydrogen peroxide and metal chelating assay, showed that the Ru(III) complexes possess excellent radical scavenging properties compared to those of Ru(II). Cytotoxicity studies using three cancer lines viz HeLa, HepG2, HEp-2 and a normal cell line NIH 3T3 showed that Ru(II) complexes exhibited substantial cytotoxic specificity towards cancer cells. Furthermore, the Ru(II) complexes were found to be superior to Ru(III) complexes in inhibiting the growth of cancer cells.

4-(8-Eth-oxy-2,3-dihydro-1H-cyclo-penta-[c]quinolin-4-yl)butane-1-peroxol.

In the title mol-ecule, C(18)H(23)NO(3), the hydro-per-oxy-butyl substituent is nearly fully extended, with the four torsion angles in the range 170.23 (10)-178.71 (9)°. The O-O distance in the hydro-peroxide group is 1.4690 (13) Å. This group acts as an inter-molecular hydrogen-bond donor to a quinoline N atom. This results in dimeric units about the respective inversion centers, with graph-set notation R(2) (2)(18).

(S)-(Z)-Methyl 2-[2,3-bis-(benzyl-oxy-carbon-yl)guanidino]-4-methyl-penta-no-ate.

The title mol-ecule, C(24)H(29)N(3)O(6), has a nearly planar ten-atom C(3)N(3)O(4) core, on account of both N-H groups forming six-membered-ring intra-molecular hydrogen bonds to carbamate carbonyl O atoms. The absolute configuration was determined from resonant scattering of light atoms in Mo Kα radiation, agreeing with the configuration of starting materials.

11ß,13-Dihydro-lactucin-8-O-acetate hemihydrate.

THE TITLE STRUCTURE (SYSTEMATIC NAME: 9-hydroxy-methyl-3,6-di-methyl-3-methyl-ene-2,7-dioxo-3,3a,4,5,9a,9b-hexa-hydro-azu-leno[4,5-b]furan-4-yl acetate hemihydrate), C(17)H(20)O(6)·0.5H(2)O, from Lactuca floridana, has two independent sesquiterpene lactone mol-ecules in the asymmetric unit. Both have their seven-membered rings in the chair conformation. In the crystal, the OH groups and the water mol-ecule form classical O-H⋯O hydrogen bonds with O⋯O distances in the range 2.6750 (17)-2.8160 (18) Å.

A cycloaddition product of a chiral maleimide: 4-{(3aS*,6aS*)-4,6-dioxo-1-phenyl-5-[(1R)-1-phenyl-ethyl]-1,3a,4,5,6,6a-hexa-hydro-pyrrolo[3,4-c]pyrazol-3-yl}phenyl acetate.

In the title mol-ecule, C(27)H(23)N(3)O(4), the two central five-membered rings form a dihedral angle of 63.66 (4)°. The absolute configuration was determined by analysis of Bijvoet pairs based on resonant scattering of light atoms, yielding a Hooft parameter y = -0.10 (7).

(3aR,6aR)-1-Phenyl-5-[(R)-1-phenyl-ethyl]-3-[4-(trifluoro-meth-yl)phen-yl]-1,6a-dihydro-pyrrolo[3,4-c]pyrazole-4,6(3aH,5H)-dione.

In the title mol-ecule, C(26)H(20)F(3)N(3)O(2), the two central five-membered rings form a dihedral angle of 62.94 (8)°. The absolute configuration was determined by analysis of Bijvoet pairs based on resonant scattering of light atoms, yielding a Hooft parameter y = -0.05 (11). Notable intra- and inter-molecular contacts include C-H⋯O and C-H⋯π(arene) hydrogen bonds.