Quantitative phytochemical profile, cholinesterase enzyme inhibition assay, antibacterial and antioxidant activities of Sarcococca saligna.

Aqueous methanol extracts of Sarcococca saligna leaves and roots were used in this work to explore its phytochemical contents, antioxidant, enzyme inhibition and antibacterial activities. Total phenolic contents were found to be in higher concentrations then total flavonoids contents in aqueous methanolic extracts of leaves. Antioxidant activity was performed using DPPH radical scavenging assay. In our findings both leaves and roots extracts were found to show substantial antioxidant potential. Aqueous methanolic extracts of both the leaves and roots gave significant inhibition against butyryl cholinesterase whereas against acetyl cholinesterase extracts of roots gave significant inhibition. The results were compared with the standard drug Eserine. The aqueous methanolic extract of leaves, roots and crude saponins isolated from leaf extracts gave moderate to significant antibacterial activity against the tested bacterial strains using agar disc diffusion method. According to the conclusions, S. saligna possesses significant antioxidant, enzyme inhibition, and antibacterial activities. Hence it is assumed that S. saligna has the potential to be used in the discovery and development of new bioactive compounds.

Electronic structure and magnetism of EuTiO(3): a first-principles study.

Density-functional theory calculations were carried out for the multiferroic EuTiO(3) using the LDA+U approach. Total-energy calculations for ferromagnetic (F), and antiferromagnetic A-, C-, and G-type arrangements in the cubic phase shows that the ground-state magnetic configuration is G-type antiferromagnetic for U≤6 eV and ferromagnetic for U≥7 eV. Values of first- and second-neighbour exchange integrals have been calculated by mapping the energy difference between the different magnetic configurations to a Heisenberg Hamiltonian. The system seems to be critically balanced between ferromagnetic and antiferromagnetic states for realistic values of U, and switches from antiferromagnetic to a ferromagnetic ground state on hydrostatic expansion of volume.

Ab initio electronic structures of rhombohedral and cubic HgXO3 (X = Ti, Pb).

First-principles calculations were performed for orthorhombic HgO, rhombohedral and cubic phases of HgTiO(3) (HTO) and HgPbO(3) (HPO). The calculations show that in the rhombohedral phase HTO is a direct gap insulator with a gap of ∼1.6 eV. The rhombohedral phase of HPO, on the other hand, shows a weak metallic character. The results provide an explanation for the electrical properties of these compounds. The cubic phases of HTO and HPO are invariably metallic in nature, thereby suggesting that for HTO the rhombohedral-cubic transition must also be accompanied by a change in the electrical state. Examination of the electronic density of states of these systems revealed no significant on-site mixing of Hg 5d and Hg 6s states in any of these materials.