Dimethyl 2-[(acridin-9-yl)methyl-idene]malonate.

In the title compound, C(19)H(15)NO(4), the acridine system is essentially planar (r.m.s. deviation = 0.015 Å). The crystal packing exhibits π-π inter-actions between pairs of centrosymmetric mol-ecules, one of them between the central heterocyclic rings and others between the outer benzene rings of the acridine systems, with centroid-centroid distances of 3.692 (1) and 3.754 (1) Å, respectively. These pairs are further linked by additional π-π inter-actions along the a-axis direction through one of the two outer benzene ring of neighboring mol-ecules, with a centroid-centroid distance of 3.642 (2) Å.

Ethyl 2-(3-phenyl-thio-ureido)-5,6-di-hydro-4H-cyclo-penta-[b]thio-phene-3-carboxyl-ate.

In the title compound, C(17)H(18)N(2)O(2)S(2), the angle between the mean plane defined by the atoms of the 5,6-dihydro-4H-cyclo-penta-[b]thio-phene moiety (r.m.s. deviation = 0.19 Å) and the phenyl ring is 72.8°(2). The mol-ecular conformation is stabilized by an intra-molecular N-H⋯O inter-action, which generates an S(6) ring motif. In the crystal, pairs of N-H⋯S hydrogen bonds link the mol-ecules to form inversion dimers with an R(2) (2)(8) ring motif.

Solid dispersions of imidazolidinedione by PEG and PVP polymers with potential antischistosomal activities.

Solid dispersions have been used as a strategy to improve the solubility, dissolution rate, and bioavailability of poor water-soluble drugs. The increase of the dissolution rate presented by (5Z)-3-(4-chloro-benzyl)-5-(4-nitro-benzylidene)-imidazolidine-2,4-dione (LPSF/FZ4) from the solid dispersions is related to the existence of intermolecular interactions of hydrogen bond type (>N-H···O<) between the amide group (>N-H) of the LPSF/FZ4 and the ether group (-O-) of the polyethyleneglycol polymer, or the carbonyl (C=O) of the polyvinylpyrrolidone polymer (PVP). The intensity of these interactions is directly reflected in the morphology acquired by LPSF/FZ4 in these systems, where a new solid phase, in the form of amorphous aggregates of irregular size, was identified through scanning electron microscopy and confirmed in the characterizations achieved using X-ray diffraction and thermal analysis of DSC. The solid dispersions with the polymer PVP, in higher concentrations, were revealed to be the best option to be used in the formulations of LPSF/FZ4 in both theoretical and experimental studies.

2-Amino-4,5,6,7-tetra-hydro-benzo[b]thio-phene-3-carbonitrile.

The title compound, C(9)H(10)N(2)S, was synthesized according to Gewald procedures by the reaction of cyclo-hexa-none with malonitrile and sulfur in the presence morpholine. The cyclo-hexane ring adopts a half-chair conformation and the thio-phene ring is essentially planar (r.m.s. deviation = 0.05 Å). The crystal packing is stabilized by two inter-molecular N-H⋯N hydrogen bonds, which link the mol-ecules into centrosymmetric rings with graph-set motif R(2) (2)(12).

2-(2-Nitro-anilino)-5,6,7,8-tetra-hydro-4H-cyclo-hepta-[b]thio-phene-3-carbonitrile.

The title compound, C(16)H(15)N(3)O(2)S, was synthesized by the reaction of 2-amino-5,6,7,8-tetra-hydro-4H-cyclo-hepta-[b]thio-phene-3-carbonitrile and o-fluoro-nitro-benzene. The thio-phene and nitro-phenyl rings and amino and carbonitrile groups are coplanar with a maximum deviation of 0.046 (2) Šand a dihedral angle of 0.92 (6)° between the rings. The cyclo-hepta ring adopts a chair conformation. Intra-molecular N-H⋯O and C-H⋯S inter-actions occur. In the crystal, the mol-ecules form layers that are linked by π-π stacking inter-actions between the thio-phene and benzene rings [centroid-centroid distances = 3.7089 (12) and 3.6170 (12) Å].

2-(2-Nitro-anilino)-4,5,6,7-tetra-hydro-benzo[b]thio-phene-3-carbonitrile.

The title compound, C(15)H(13)N(3)O(2)S, was synthesized by the reaction of 2-amino-5,6,7,8-tetra-hydro-4H-cyclo-hepta-[b]thio-phene-3-carbonitrile and o-fluoro-nitro-benzene. The dihedral angle between the thio-phene and nitro-phenyl rings is 75.15 (2)°. In the crystal, inter-molecular N-H⋯N and C-H⋯O inter-actions lead to the formation of a supra-molecular chain extending along the c-axis direction.

Effect of thiazolidine LPSF SF29 on the growth and morphology of Trypanosoma cruzi.

Chagas disease, caused by the protozoan Trypanosoma cruzi, is an endemic illness in Latin America. Efforts have been made by several groups to develop new effective and safe anti-T. cruzi drugs. In the present work, we show that thiazolidine LPSF SF29 inhibited growth of the epimastigote and amastigote forms and caused lysis in the trypomastigote form of T. cruzi, leading to death of the protozoan. Mitochondrial dysfunction was also observed. The thiazolidine induced ultrastructural alterations such as detachment of the flagellar membrane, intense mitochondrial swelling, formation of myelin-like figures and the appearance of autophagosomes. Taken together, these results suggest that this new thiazolidine is active against T. cruzi and constitutes a promising drug for the therapy of Chagas disease.