Drielly A. Paixão

6-Meth-oxyisobenzofuran-1(3H)-one.

In the title compound, C9H8O3, the molecular skeleton is almost planar [r.m.s. deviation = 0.016 (2) Å]. Weak intermolecular C—H⋯O and C—H⋯π interactions consolidate the crystal packing, with the molecules stacking in the [101] direction.

Three new platinum complexes containing fluoroquinolones and DMSO: Cytotoxicity and evaluation against drug-resistant tuberculosis

This work describes the synthesis, characterization and biological evaluation of three platinum complexes of the type [Pt(DMSO)(L)Cl]Cl, in which L represents a fluoroquinolone, namely, ciprofloxacin (cpl), ofloxacin (ofl), or sparfloxacin (spf). The new complexes were characterized by elemental analysis, high-resolution mass spectrometry (HRESIMS) and 1H, 13C and 195Pt NMR (nuclear magnetic resonance). The spectral data suggest that the fluoroquinolones act as bidentate ligands coordinated to Pt(II) through the nitrogen atoms of the piperazine ring. Microbiological assays against wild type Mycobacterium tuberculosis (ATCC 27294) showed that all complexes have been very potent, exhibiting antitubercular potency at concentrations <2 μM, although none of the complexes presented higher potency than established anti-TB drugs. As to the resistant strains, the complex with sparfloxacin, [Pt(DMSO)(spf)Cl]Cl exhibited the best potential against most Mycobacterium tuberculosis clinical isolates. The cytotoxicity of these compounds was also evaluated in three breast cell lines: MCF-10 (a healthy cell), MCF-7 (a hormone responsive cancer cell) and MDA-MB-231 (triple negative breast cancer cell). In both tumor cell lines, [Pt(DMSO)(spf)Cl]Cl was more active and more selective than cisplatin. Flow cytometry analysis revealed that [Pt(DMSO)(spf)Cl]Cl induced late apoptotic cell death in MDA-MB-231 cells.

Centrosymmetric resonance-assisted intermolecular hydrogen bonding chains in the enol form of β-diketone: Crystal structure and theoretical study

Isobenzofuran-1(3H)-ones (phtalides) are heterocycles that present a benzene ring fused to a γ-lactone functionality. This structural motif is found in several natural and synthetic compounds that present relevant biological activities. In the present investigation, the 3-(2-hydroxy-4,4-dimethyl-6-oxocyclohexen-1-yl)isobenzofuran-1(3H)-one was characterized by single-crystal X-ray analysis. In the crystal structure, there are two molecules per asymmetric unit. One of them exhibits resonance assisted hydrogen bonds (RAHBs). Semi-empirical and DFT calculations were performed to obtain electronic structure and π-delocalization parameters, in order to better understand the energy stabilization of RAHBs in the crystal packing of the studied molecule. The structural parameters showed good agreement between theoretical and experimental data. The theoretical investigation revealed that the RAHBs stabilization energy is directly related to the electronic delocalization of the enol form fragment. In addition, RAHBs significantly affected the HOMO and charge distribution around the conjugated system.

Bis(tetra-phenyl-phospho-nium) bis-[N-(trifluoro-methyl-sulfon-yl)dithio-carbimato(2-)-κS,S']zincate(II).

The title salt, (C24H20P)2[Zn(C2F3NO2S3)2], consists of a complex dianion and two tetraphenylphosphonium cations. The ZnII ion displays a distorted tetrahedral coordination environment with four S atoms from two S,S′-chelated N-(trifluoromethylsulfonyl)dithiocarbimate anions. In the crystal, besides the ionic interaction of the oppositely charged ions, intermolecular C—H⋯O interactions between cations and anions are observed. One of the cations interacts with an inversion-related equivalent by π–π stacking between phenyl rings, with a centroid–centroid distance of 3.932 (4) Å.

5-Meth­oxy-2-benzofuran-1(3H)-one

In the title compound, C9H8O3, the molecular skeleton is almost planar, with an r.m.s. deviation of 0.010 (2) Å. In the crystal, weak C—H⋯O hydrogen bonds connect the molecules into a two-dimensional network parallel to the ac plane.

N-(2-Nitro-oxyeth-yl)picolinamide.

In the title molecule, C8H9N3O4, the amide group is involved in the formation of an intramolecular N—H⋯N hydrogen bond. In the crystal, molecules related by translation along the a axis are linked into chains via weak intermolecular C—H⋯O interactions.