Thermal Expansion in Layered Na MO.

Layered oxide Na MO (M: transition metal) is a promising cathode material for sodium-ion secondary battery. Crystal structure of O3- and P2-type Na MO with various M against temperature (T) was systematically investigated by synchrotron x-ray diffraction mainly focusing on the T-dependences of a- and c-axis lattice constants (a and c) and z coordinate (z) of oxygen. Using a hard-sphere model with minimum Madelung energy, we confirmed that c/a and z values in O3-type Na MO were reproduced.

Structure-activity relationship and biological property of cortistatins, anti-angiogenic spongean steroidal alkaloids.

Previously, bioassay-guided separation led us to isolate eleven novel steroidal alkaloids named cortistatins from the marine sponge Corticium simplex. These cortistatins were classified into three types based on the chemical structure of the side chain part, that is, isoquinoline, N-methyl piperidine or 3-methylpyridine units. From the structure-activity relationship study, the isoquinoline unit in the side chain was found to be crucial for the anti-angiogenic activity of cortistatins.