Two tetramethyl-substituted dispiro-1,2,4,5-tetraoxanes (7,8,15, 16-tetraoxadispiro[5.2.5.2]hexadecanes) 3 and 4 were designed as metabolically stable analogues of the dimethyl-substituted dispiro-1, 2,4,5-tetraoxane prototype WR 148999 (2). For a positive control we selected the sterically unhindered tetraoxane 5 (7,8,15, 16-tetraoxadispiro[5.2.5.2]hexadecane), devoid of any substituents. Tetr...

Sixteen alkyl-substituted dispiro-1,2,4,5-tetraoxanes (7,8,15, 16-tetraoxadispiro[5.2.5.2]hexadecanes) were synthesized to explore dispiro-1,2,4,5-tetraoxane SAR and to identify tetraoxanes with better oral antimalarial activity than prototype tetraoxane 1 (WR 148999). The tetraoxanes were prepared either by peroxidation of the corresponding cyclohexanone derivatives in H(2)SO(4)/CH(3)CN or by ...

Eleven novel dispiro-1,2,4,5-tetraoxanes 3 bearing unsaturated and polar functional groups were designed to enhance the oral antimalarial activity of the prototype tetraoxane 2 (WR 148999). With the exception of 3g and 3h, tetraoxanes 3 were available via the peroxidation of corresponding cyclohexanone derivatives in H2SO4/CH3CN. Tetraoxanes 3g and 3h were prepared by hydrolysis of ester tetrao...

Dispiro-1,2,4,5-tetraoxanes 2-4 were synthesized as potential peroxide antimalarial drugs. They had curative activity against Plasmodium berghei in vivo at single doses of 320 and 640 mg/kg which confirms earlier unpublished data. Moreover, artemisinin (1) and 4 had equivalent ED50's against P. berghei in vivo in the multiple-dose Thompson test; neither showed any evidence of acute toxicity at ...

We investigated whether the C1245G polymorphism of human 8-oxoguanine glycosylase 1 (hOGG1) gene confers the susceptibility to systemic lupus erythematosus (SLE) occurrence of lupus nephritis and affects the plasma level of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in patients with SLE. A total of 45 healthy controls and 85 SLE patients were recruited. The C1245G polymorphism of the hOGG1 gene was d...

Single crystals of triclinic Pr(2)(B(2)O(5))(MoO(4)) were prepared from an incongruently melting flux in the system Pr(2)O(3)-MoO(3)-B(2)O(3) in a platinum crucible in an atmosphere of air. In the crystal structure, distorted edge-sharing [PrO(8)] square anti-prisms form a three-dimensional framework. These are further linked by isolated [MoO(4)] tetra-hedra and isolated pyroborate groups [B(2)...

In the title mol-ecular salt, (C(13)H(22)N)[FeCl(4)], three of the chloride ions of the tetra-hedral Fe(III)-containing anion are disordered over two orientations in a 0.656 (11):0.344 (11) ratio. In the crystal, there are no identifiable directional inter-actions between cations and anions except for Coulombic forces.

The zwitterionic title compound, C(13)H(8)F(2)N(4)S, is situated on a twofold rotation axis running along the C-S [1.691 (2) Å] single bond. The phenyl-ene ring is twisted out of the tetra-zolium plane by 42.18 (7)°. Relatively short distances [3.7572 (9) and 4.0625 (6) Å] between the centroids of the phenyl-ene and tetra-zolium rings of neighbouring mol-ecules suggest π-π inter-actions. The cr...

Animal studies have shown that visual deprivation during the first months of life permanently impairs the interactions between sensory systems. Here we report an analogous effect for humans who had been deprived of pattern vision for at least the first five months of their life as a result of congenital binocular cataracts. These patients showed reduced audiovisual interactions in later life, a...

Single crystals of the title compound, Li(3)Sc(BO(3))(2), have been obtained by spontaneous nucleation from a high-temperature melt. The title compound adopts a framework structure and is composed of distorted [ScO(6)] octa-hedra, [LiO(4)] tetra-hedra, [LiO(4)] recta-ngles and isolated [BO(3)] triangles. Except for the Sc and one Li atom (both on inversion centres), all atoms are in general pos...