7 research outputs found

    Evaluation of Morphological Traits and Oil Contents of Achillea aucheri from Different Altitudes

    Get PDF
    Yarrow (Achillea spp.) belonging to the family of Asteraceae with useful properties, such as anti-diaphoretic, anti-hemorrhagic, anti-inflammation, anti-biotic, anti-fungal, anti-bacterial, Carminative and anti-oxidant effects. The present investigation assessed the morphological diversity of Achillea aucheri, which is indigenous plant from Damavand mountain of Iran. The samples were collected from five heights of Damavand and the morphological traits were studied. For estimating the percentage of essential oil, aerial parts were collected and oil was isolated by hydro distillation using Clevenger-type apparatus. The results of present study demonstrated that the highest plant height, internodes, biomass and number of leaves per node obtained at lowest altitude (3900 meters from sea level). In addition, fresh weight and dry weight of plant had the highest amount in altitude of 3900 meter from sea level. But essential oil content increased from low altitude to high altitude from 0.681% to 0.954%. Also high altitude had high significantly differences on the essential oil content. It revealed that plants in lower altitudes produce more biomass than higher altitudes, but essential oil content of plants was more in higher altitudes. It seems that a part of photosynthetic energy of plants in higher altitudes expend to produce secondary metabolites especially essential oils to overcome stress and survival in inappropriate conditions

    Approaches to Photoactivated Cytotoxins

    Get PDF
    The synthesis and coordination chemistry of eleven bridging ligands, eight of which are new compounds, are described. These ligands are all based on the tridentate terpyridyl system. The other metal ion binding sites of these ligands contain pyridine/bipyridine/pyrazole rings or amine/azamacrocycles domains. In these ligands, the two metal ion binding sites are differentiated by the number of atoms in each site, the configuration of the binding site or the types of donor atom that are present. This binding site differentiation allows to use the different coordination properties of the binding sites to control the regiochemistry of the complexation, ensuring that the correct metal ion is incorporated at the correct binding site in the ligand. Many of the complexes synthesised are mono-ruthenium(II) complexes where Ru(II) ions are situated in the terpyridyl sites of the ligands. These include heteroleptic Ru(II) complexes of the type [Ru(ttp)(L)]2+, where ttp is 4'-(p-tolyl)-2,2':6',2ʺ- terpyridine, and L is the bridging ligand. Reactions of the Ru(II) complexes with a range of metal ions including Co(III) ion have been investigated. The Ru(II) complexes can be classified into three main categories depending on the type of ligands that have been employed: (1) Ru(II) complexes which can react with Co(III) ions to form heterodinuclear Ru(II)-Co(III) complexes; (2) Ru(II) complexes which react only with Ag(I) ions and no other common metal ions that we have tried; (3) Ru(II) complexes with no detectable ability to coordinate other common metal ions. Following standard cobalt chemistry, some heterodinuclear Ru(II)-Co(III) complexes of the type [(ttp)Ru(cymt)Co(X)2]3+, where X = NO2 -, Cl-, and OH-, have been successfully prepared from the corresponding Ru(II) complexes. In these heterodinuclear complexes, anions such as NO2 -, Cl-, or OH- can be readily attached to the Co(III) ions. However, attachment of a neutral species such as en ligands to the Co(III) ions in the complexes proved to be more difficult. Reactions of heterodinuclear Ru(II)-Co(III) complexes with en ligands result in removal of the cobalt ions from the complexes. This is may be a result of a significant difference in the overall charges between the complexes with anionic and the complexes with neutral ligands (3+ vs 5+). Higher overall charge of the complexes when protonable ligands such as monodentate en are present, may destabilize the complexes even more. A combination of NMR spectroscopy, ESI-MS, UV-vis spectroscopy, elemental analysis, and X-ray crystallography has been used to characterise the ligands and their complexes. The crystal structures of one new ligand and sixteen complexes are described

    Hexaaquacopper(II) dinitrate: absence of Jahn–Teller distortion. Corrigendum

    No full text
    The identity of the metal atom in the paper by Zibaseresht & Hartshorn [Acta Cryst. (2006), E62, i19–i22] is corrected
    corecore