Dihydrochalcones in Sweet Tea: Biosynthesis, Distribution and Neuroprotection Function.

Sweet tea is a popular herbal drink in southwest China, and it is usually made from the shoots and tender leaves of The sweet taste is mainly attributed to its high concentration of dihydrochalcones. The distribution and biosynthesis of dihydrochaldones in sweet tea, as well as neuroprotective effects in vitro and in vivo tests, are reviewed in this paper. Dihydrochalones are mainly composed of phloretin and its glycosides, namely, trilobatin and phloridzin, and enriched in tender leaves with significant geographical specificity.

A Quasi-relativistic Density Functional Theory Study of the Actinyl(VI, V) (An = U, Np, Pu) Complexes with a Six-Membered Macrocycle Containing Pyrrole, Pyridine, and Furan Subunits.

Actinyl(VI, V) (An = U, Np and Pu) complexes of the recently reported hybrid macrocycle, cyclo[1]furan[1]pyridine[4]pyrrole (denoted as H4L), have been studied using density functional theory in combination with the small-core scalar-relativistic effective core potentials and corresponding (14s13p10d8f6g)/[ 10s9p5d4f3g] basis sets in the segmented contraction scheme. On the basis of our calculations, the pyrrole nitrogen atoms that possess the shortest An-L bonds and strongest basicity are the main donor atoms that contribute to the formation of actinyl(VI, V) complexes. The natural population analysis (NPA) suggests higher ligand-to-actinyl charge transfer in the actinyl(VI) complexes than in their actinyl(V) analogues, which account for the higher decomposition energies of the former.

Thermodynamic study on the complexation of Am(III) and Eu(III) with tetradentate nitrogen ligands: a probe of complex species and reactions in aqueous solution.

A thermodynamic investigation has been performed to study the complexation of trivalent metal (M) ions (M = Am(III), Eu(III)) with tetradentate ligands (L), 6,6'-bis(5,6-dialkyl-1,2,4-triazin-3-yl)-2,2'-bipyridines (BTBPs), by using relativistic quantum mechanical calculations. The structures and stabilities of the inner-sphere BTBPs complexes were explored in the presence of various counterions such as NO(3)(-), Cl(-), and ClO(4)(-). According to our calculations, Am(III) and Eu(III) can chelate eight or nine water molecules at most, whereas more stable species like M(NO(3))(3)(H(2)O)(4) tend to be formed in the presence of nitrate ions.