Two pseudo-enantiomeric forms of N-benzyl-4-hydroxy-1-methyl-2,2-dioxo-1H-2λ(6),1-benzothiazine-3-carboxamide and their analgesic properties.

The fact that molecular crystals exist as different polymorphic modifications and the identification of as many polymorphs as possible are important considerations for the pharmaceutic industry. The molecule of N-benzyl-4-hydroxy-1-methyl-2,2-dioxo-1H-2λ(6),1-benzothiazine-3-carboxamide, C17H16N2O4S, does not contain a stereogenic atom, but intramolecular hydrogen-bonding interactions engender enantiomeric chiral conformations as a labile racemic mixture. The title compound crystallized in a solvent-dependent single chiral conformation within one of two conformationally polymorphic P212121 orthorhombic chiral crystals (denoted forms A and B).

6-Hy-droxy-1,2-dihydro-4H-pyrrolo-[3,2,1-ij]quinolin-4-one.

The mol-ecule of the title compound, C11H9NO2, is essentially planar [r.m.s.

4-Hydroxy-1-methyl-2-oxo-N-(4-oxo-2-propyl-3,4-dihydroquinazolin-3-yl)-1,2-dihydroquinoline-3-carboxamide.

The two bicyclic fragments of the title compound, C(22)H(20)N(4)O(4), are individually planar and are turned with respect to each other by 77.8 (2) degrees. The formation of intramolecular O-H.

[Mg2+-dependent interaction of DNA with eukaryotic cells].

Interaction of DNA with eukaryotic cells under conditions similar to those providing DNA adsorption onto liposomes was studied. It was revealed that mouse fibroblasts (line A9) and myeloma cells bind phage and plasmid DNA in 0.3 M sucrose solution containing Mg2+-ions.

[Effect of polynucleotide adsorption on characteristics of a planar phosphatidylcholine bilayer membrane].

Interaction of DNA with planar bilayer phosphatidylcholine membrane in the presence of CaCl2 increases electric conductance of the membrane several times as a result of the formation of DNA-membrane complex. The same effect was observed in the cases of ribosomal RNA and synthetic homopolymers polyA, polyU and polyA X polyU double helix.