Chiral Chromium(III) Complexes as Promising Candidates for Circularly Polarized Luminescence

This work is supported through grants from the Swiss National Science Foundation (grant 200020178758).The search for chiral chromophores with efficient circularly polarized luminescence (CPL) is an on-going hot topic in chemistry due to their potential applications in emerging fields such as spintronics and photonics. Beyond the largely exploited p-block, 4d/5d-block and f-block chiral entities, chiral chromium (III) complexes have recently attracted interest because of the abundancy of chromium in the earth’s crust, its kinetic inertness and its promising metal-centered Cr(2E) and Cr(2T1) phosphorescence. The associated spin-flip transitions could provide large dissymmetric factor (glum) and high luminescence quantum yields (ϕ) when six-membered strong-field chelate rings are coordinated to chiral six-coordinate Cr(III) centers. In this minireview, we intend to focus our attention on the state-ofthe- art for the design of pseudo-octahedral chiral mononuclear Cr(III) complexes for which chiroptical properties were investigated. The promising electronic properties of these complexes together with their low cost make these underexplored systems appealing candidates for CPL applications.Swiss National Science Foundation (SNSF) European Commission 20002017875

Activity of minocycline against Toxoplasma gondii infection in mice

The chemotherapeutic activity of minocycline, a semi-synthetic tetracycline analogue, was evaluated in a murine model of toxoplasmosis. A lethal acute toxoplas-mosis was produced by injecting 105 tachyzoites of the RH strain of Toxoplasma gondii into the peritoneal cavities of Swiss-Webster mice. When infected mice were treated once daily for 12 days, starting 2 h after challenge, the survival and cure rates were 100% and 40% respectively after minocycline alone (100 mg/kg per day), 0% and 0% after pyrimethamine alone (8.5 mg/kg per day), and 100% and 50% after combination of the two drugs at the same dosages. Absolute survival and cure with minocycline were observed when mice were treated with two daily doses of 100 mg/kg for 12 days. Mice chronically infected with a low virulent strain of T. gondii (Me49) showed a significant reduction in the number of brain cysts after three weeks of treatment with 50 mg/kg per day of minocycline. Minocycline serum levels after a single oral administration of 50 mg/kg or 100 mg/kg to normal mice, peaked at 1.8 mg/1 and 10 mg/1 after 1 h, respectively, and showed an extended half-lif