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The nickel content in different parts of the hyperaccumulating tree Sebertia acuminata was analysed by atomic absorption spectroscopy. Nickel was found to be mainly located in laticifers. The total nickel content of a single mature tree was estimated to be 37 kg. By gel filtration and NMR spectroscopy, citric acid was unequivocally identified as counter ion(More)
Alternative agriculture, which expands the uses of plants well beyond food and fiber, is beginning to change plant biology. Two plant-based biotechnologies were recently developed that take advantage of the ability of plant roots to absorb or secrete various substances. They are (i) phytoextraction, the use of plants to remove pollutants from the(More)
Engineering plants with greater metal tolerance and accumulation properties is the key to developing phytoremediators. A recent study by Won-Yong Song et al. has shown that overexpressing the yeast vacuolar transporter YCF1 increases Pb and Cd tolerance and consequently increases the accumulation of these metals in shoots of transgenic Arabidopsis plants(More)
Root extracts from the arsenic (As) hyperaccumulating Chinese brake fern (Pteris vittata) were shown to be able to reduce arsenate to arsenite. An arsenate reductase (AR) in the fern showed a reaction mechanism similar to the previously reported Acr2p, an AR from yeast (Saccharomyces cerevisiae), using glutathione as the electron donor. Substrate(More)
Plant extracts collected from the wild are important sources for drug discovery. However, these extracts suffer from a lack of reproducible bioactivity and chemical composition caused by the highly inducible, variable, and transitory nature of plant secondary metabolism. Here, we demonstrate that exposing roots of hydroponically grown plants to chemical(More)
In fungi, cellular resistance to heavy metal cytotoxicity is mediated either by binding of metal ions to proteins of the metallothionein type or by chelation to phytochelatin-peptides of the general formula (γ-Glu-Cys)n-Gly. Hitherto, only one fungus, Candida glabrata has been shown to contain both metal inactivating systems. Here we show by unambiguous(More)
Phytochemical investigation on the leaves of Labisia pumila (Myrsinaceae), an important medicinal herb in Malaysia, has led to the isolation of 1-O-methyl-6-acetoxy-5-(pentadec-10Z-enyl)resorcinol (1), labisiaquinone A (2) and labisiaquinone B (3). Along with these, 16 known compounds including 1-O-methyl-6-acetoxy-5-pentadecylresorcinol (4),(More)
The metabolites of three species of Apiaceae, also known as Pegaga, were analyzed utilizing (1)H NMR spectroscopy and multivariate data analysis. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) resolved the species, Centella asiatica, Hydrocotyle bonariensis, and Hydrocotyle sibthorpioides, into three clusters. The saponins,(More)
  • J. Krautter, F.-J. Zickgraf, +5 authors R. Mujica
  • 1999
We present the statistical evaluation of a count rate and area limited complete sample of the ROSAT All-Sky Survey (RASS) comprising 674 sources. The RASS sources are located in six study areas outside the galactic plane (|bII | >∼ 20◦) and north of δ = −9◦. The total sample contains 274 (40.7%) stars, 26 (3.9%) galaxies, 284 (42.1%) AGN, 78 (11.6%)(More)
Reducing metal machining costs and harmful effects to the environment are the main benefits of dry machining compared to the application of cooling lubricants during machining processes. The abandonment of any lubricants is causing higher temperatures of workpiece, chip, and tool. Thus, the temperature gradient varies with time and space over the workpiece,(More)
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