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The effect of 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO), a nitric oxide (NO) scavenger that yields nitrogen dioxide (NO(2)) in a rat endotoxemia model was investigated. Endotoxin (lipopolysaccharide [LPS]) increased NO synthase (NOS) activity and inducible NOS expression measured in lung and plasma levels of nitrite/nitrate, 6-oxo-prostaglandin (PG) F(1alpha), thromboxane B(2), and PGF(2alpha). Infusion of cPTIO significantly reduced LPS-induced mean arterial blood pressure decline and mortality and selectively reduced LPS-induced 6-oxo-PGF(1alpha) plasma levels and prostacyclin synthase (PGIS) activity measured in the lung and aorta. In vitro, PGIS activity in aorta rings was not modified by SNAP (NO donor), cPTIO slightly inhibited the enzyme but not in the presence of L-N(G)-monomethyl arginine, and SNAP in combination with cPTIO significantly inhibited PGIS. Thus, cPTIO may be beneficial in endotoxic shock because of NO scavenging and PGIS inactivation, which could be mediated by NO(2).

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Benzylic-type methyl and methylene groups can be converted either to the corresponding alkyl halide, alcohol or carbonyl compounds by treating different substituted 3-nitro-and 3-alkylaminosulfonylpyrroles with the adequate oxidizing agent.

Poster Sessions C568 described for Form E, resulting in a two-phase system: the neutral free base (common to both decomposition processes) and, in the present case, a novel Zolpidem tartrate monohydrate, unique to the "aging driven" decomposition. Our R.T. single crystal analysis gives for the free base comparable results as the H.T. XRPD ones already reported: orthorhombic, Pcba, a= 9.6360 (10)Å, b= 18.2690 (5)Å, c= 18.4980 (11)Å, V= 3256.4 (4)Å 3 . The unreported Zolpiden tartrate monohydrate, instead, crystallizes in monoclinic P2 1 , which for comparison purposes we treated in the non-standard setting P112 1 with a= 20.7582 (9)Å, b=15.2331 (5)Å; c= 7.2420 (2)Å, γ= 90.826 (2)°, V= 2289.73 (14) Å 3. The structure presents two complete moieties in the asymmetric unit (z=4, z'=2). The different phases obtained in both decompositions are readily explained considering the diverse genesis of both processes.[ [3]. Their crystal structures have been largely studied: over 300 are reported. The study of different phases (polymorphs, salts, co-crystals) is relevant because properties strongly depend on crystal structure; therefore, about 13% of the structures quoted above are polymorph. In one remarkable case, 10 polymorphs have been found for a single compound [4].Derivatives of 2-phenyl-4,4,5,5-tetramethyimidazoline-1-oxyl 3-oxide (PTIO) react with •NO to form the corresponding iminonitroxides (PTIs) and •NO 2 . Under inflammatory conditions, •NO is produced in much greater amount than normally, undergoing transformations which cause tissue damage, therefore the •NO scavenger behaviour of nitronyl nitroxides is interesting to be used as potential therapeutic agents [1], [2].2-(4-Carboxyphenyl)-4,4,5,5-tetramethyimidazoline-1-oxyl-3-oxide (cPTIO) is a compound similar to PTIO studied by some of us [5]. It has been shown that cPTIO exerts beneficial actions on systemic inflammatory response.Some crystal phases of cPTIO have been described including cocrystals and salts [6], [7]. In the context of a study on cPTIO crystal phases, it is presented here the new crystal structure of the cPTIO perchlorate whose free radical nature has been stated by means of EPR. Suitable single crystals of cPTIO perchlorate (intense orange colour) have been studied using X-ray diffraction. Crystals are monoclinic (P2 l /n, Z=4) having the following unit-cell parameters: a=7.815(2), 20.736(4), 10.478(2) Ǻ, β =91.83(3)º.The comparison with cPTIO crystal structure [8] shows that N-O bond lengths are shorter (1.22 vs.1.30 Ǻ) being the rest of bond distances very similar. The imidazoline ring is plane whereas in cPTIO adopts a half-chair conformation. The crystal packing is also different, in cPTIO, molecules are linked by COOH•••O-N(nitroxide) H-bonding and form infinite zigzag chains whereas in the present structure, organic ion is surrounded by perchlorate groups and no chains are formed. The system of two malic acid enantiomers (components of the system) is typical example of a binary chiral system. It forms limited solid solutions as well...