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Elsholtzia splendens (Lamiaceae) is a copper-tolerant plant species growing on copper deposits in the south of China. Chromatographic separation of n-BuOH extracts from the flowering aerial biomass afforded apigenin-7-O-β-D-glycoside, using macroporous resin, Sephadex™ LH-20 gel, polyamide resin as well as preparative high-performance liquid chromatography (P-HPLC) columns. Chemical structure was elucidated using HPLC/ESI-MS (electrospray ionization-mass spectrometry), Fourier transform infrared (FTIR), and (1)D- and (2)D-nuclear magnetic resonance (NMR). Apigenin-7-O-β-D-glycoside could be the post-harvesting product from E. splendens biomass.

Solution culture was carried to investigate capacity of synthetic aminopolycarboxylic acids (ethylenediamine tetraacetate, N-hydroxyethylenediaminetriacetic acid, and diethylenetriamine-pentaacetate) for enhancing botanical removal and transport of heavy metals (Cu and Zn) by plants. Biodegradable organic acids (citric acid, malic acid, and oxalic acid) were also selected as alternatives to compare them with synthesized chelating agents for effectiveness. Young rice seedlings (Oryza sativa L. cv. XZX 45) were grown in nutrient solutions treated with single or combined metal solutions in presence or absence of chelating compounds. Calculation by chemical equilibrium program VISUAL MINTEQ showed that different chelating compounds had various complex potential with Cu(2+) and Zn(2+) ions, in which synthetic chelators exhibited higher complexed capability than biodegradable organic acids. All applied synthetic aminopolycarboxylic acids significantly decreased removal of metal from nutrient solution (p < 0.01), while more or less effects of organic acids supplied on biosorptive potential were observed with all treatments (p > 0.05), compared with the treatment without metal ligands. Synthetic aminopolycarboxylic acids significantly decreased metal concentrations in plant materials in all treatments (p < 0.01). However, biodegradable organic acids decreased metal concentrations in roots (p < 0.01), but enhanced them in shoots (p < 0.01). Results obtained indicated that synthetic aminopolycarboxylic acids decreased uptake of metals by rice seedlings, but translocation of metals complexed within plant materials was evident. Although exogenous biodegradable organic acids showed negligible effect on botanical removal of metals, metals complexed with organic acids was more mobile than those complexed with other chelating agents. These information collected here had important implication for the use of biodegradable metal chelators in transport of essential micronutrients in plant nutrition.

Abstract The objective of this study was to discuss the phytoremediation potential of Leersia hexandra Swartz in Cu contaminated soil and its enhancement by agronomic management practices. The results showed that L. hexandra had a high extraction capacity for copper (Cu), and Cu concentration was found maximum in shoots (755.4 mg/kg), which is very close to the Cu-hyperaccumulators. Three successive harvests did not reduce the biomass and Cu level in shoots of L. hexandra (p > 0.05), indicating that sequential harvest was feasible for the increase of total biomass and Cu extraction amount. Fertilization could obviously increase the tissue dry weight, resulting in the total amount of extracted-Cu up to 52.3%. 3-Indole acetic acid (IAA) also significantly increased biomass, causing the efficiency of Cu phytoextraction up to 204.6%. These suggested that fertilization and IAA were effective for enhancing Cu phytoextraction by L. hexandra. [ABSTRACT FROM AUTHOR]

This study used hydroponics with different copper (Cu) concentrations to assess metal accumulation and growth in two different populations ofLeersia hexandraSwartz, one obtained from a contaminated area (CP) and the other from a non-contaminated area (NCP). Data demonstrated that Cu exerted a lesser effect on the biomass of CP than NCP. The root and shoot biomass measurements of CP were significantly higher than those noted at NCP. Copper concentration in the tissues ofL. hexandrafrom CP increased markedly correlated with the concentration of metal in the culture solution, and this trend was stronger than that in NCP. Copper concentrations in roots and shoots were significantly higher in CP than NCP. As Cu stress levels in the culture solution rose, the transport coefficient of both populations decreased. Furthermore, the coefficient of CP was significantly higher than NCP. At a Cu concentration of 38.4 mg/L, the transfer factor value of CP is 40% higher than NCP. In summary, CP showed higher accumulation and resistance to Cu compared with NCP. [ABSTRACT FROM PUBLISHER]

Abstract: The lotus-leaf-like superhydrophobic copper was fabricated by a facile two-step method without the chemical modification, on which the water contact angle can reach 158° and the water-sliding angle is less than 10°. Reversible superhydrophobicity to superhydrophilicity transition was observed and controlled by alternation of UV irradiation and dark storage. More interestingly, the superhydrophobic surface exhibits superoleophilicity and all those properties can be well used in reversible switch, separating the water and oil and so on. [Copyright &y& Elsevier]