A new strategy for inducing dipole moments in charge-transfer complexes: introduction of asymmetry into axially ligated iron phthalocyanines.

Introduction of asymmetry into charge-transfer complexes composed of axially ligated iron phthalocyanines was achieved. In the obtained crystals of TPP[FeIII(Pc)(CN)Cl]2, TPP[FeIII(Pc)(CN)Br]2, and TPP[FeIII(Pc)BrCl]2 (TPP = tetraphenylphosphonium and Pc = phthalocyanine), the axial positions of the iron atoms were occupied by 50/50 ratios of the ligands CN/Cl, CN/Br, and Br/Cl, respectively. The crystal structures of the obtained CT complexes were isostructural to those composed of the symmetric analogues of the type [FeIII(Pc)L2] (L = CN, Cl or Br); the [FeIII(Pc)LL'] units formed regular one-dimensional chains along the c-axis following the symmetry of the P42/n space group. Despite forming similar regular chains to the symmetric systems, the electrical resistivities and activation energies were enhanced in the obtained CT complexes compared to those in symmetric systems, indicating that the charge-ordered states were stabilised by the introduction of asymmetry. More specifically, the dielectric relaxation behaviour of the inhomogeneous disordered TPP[FeIII(Pc)(CN)Cl]2 probably suggests that a dipole moment was induced in this material.

Acute necrotizing encephalopathy associated with hemophagocytic syndrome.

A 7-year-old female suddenly exhibited high fever and convulsions, and entered a semi-coma. She also had thrombocytopenia, elevated aminotransferase, prolonged prothrombin time and activated partial thromboplastin time, and hemophagocytes in the bone marrow. The brain magnetic resonance imaging revealed multiple low-intensity areas on the T1-weighted images, and high-intensity areas on the T2-weighted images bilaterally in the thalamus, the dorsal part of the pons, and the cerebellar white matter. The patient was diagnosed as having both acute necrotizing encephalopathy and hemophagocytic syndrome. Serum and cerebrospinal fluid interleukin-6 and tumor necrosis factor-alpha were elevated to the same high levels (serum:cerebrospinal fluid interleukin-6, 103:101 pg/mL; tumor necrosis factor-alpha 753:753 pg/mL). The clinical symptoms and the magnetic resonance imaging findings improved immediately after the administration of dexamethasone. These results suggest that the hypercytokinemia and the hyperpermeability of both the blood-brain barrier and the capillary walls of the central nervous system might be essential in the pathogenesis of acute necrotizing encephalopathy, and that early steroid therapy might be effective in these conditions.

Cytotoxic diterpenoids from Vietnamese medicinal plant Croton tonkinensis GAGNEP.

Six new ent-kaurane-type diterpenoids were isolated from the leaves of the endemic Vietnamese medicinal plant Croton tonkinensis GAGNEP. (Euphorbiaceae) together with three known ent-11alpha-acetoxy-7beta,14alpha-dihydroxykaur-16-en-15-one (1), ent-kaur-16-en-15-one 18-oic acid (5) and ent-18-hydroxykaur-16-ene (7). Their structures were determined by spectroscopic analyses to be ent-7beta-acetoxy-11alpha-hydroxykaur-16-en-15-one (2), ent-18-acetoxy-11alpha-hydroxykaur-16-en-15-one (3), ent-11alpha-acetoxykaur-16-en-18-oic acid (4), ent-15alpha,18-dihydroxykaur-16-ene (6), ent-11alpha,18-diacetoxy-7beta-hydroxykaur-16-en-15-one (8), and ent-(16S)-1alpha,14alpha-diacetoxy-7beta-hydroxy-17-methoxykauran-15-one (14). ent-Kaurane-type diterpenoids from Croton tonkinensis 2-4, 6, and 9-13, were tested for toxicity in the brine shrimp lethality assay. Compounds 9, 10, and 12 demonstrated significant activity, compounds 2, 3, 6, and 11 showed weak activity, and compounds 4 and 13 were inactive.