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Rok Martin?i? Janez Mravljak Urban ?vajger Andrej Perdih Marko Anderluh Marjana Novi? 《PloS one》2015,10(10)
A pigment from the edible mushroom Xerocomus badius norbadione A, which is a natural derivative of pulvinic acid, was found to possess antioxidant properties. Since the pulvinic acid represents a novel antioxidant scaffold, several other derivatives were recently synthetized and evaluated experimentally, along with some structurally related coumarine derivatives. The obtained data formed the basis for the construction of several quantitative structure-activity and pharmacophore models, which were employed in the virtual screening experiments of compound libraries and for the prediction of their antioxidant activity, with the goal of discovering novel compounds possessing antioxidant properties. A final prioritization list of 21 novel compounds alongside 8 established antioxidant compounds was created for their experimental evaluation, consisting of the DPPH assay, 2-deoxyribose assay, β-carotene bleaching assay and the cellular antioxidant activity assay. Ten novel compounds from the tetronic acid and barbituric acid chemical classes displayed promising antioxidant activity in at least one of the used assays, that is comparable to or even better than some standard antioxidants. Compounds 5, 7 and 9 displayed good activity in all the assays, and were furthermore effective preventers of oxidative stress in human peripheral blood mononuclear cells, which are promising features for the potential therapeutic use of such compounds. 相似文献
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The amphibious plant species of intermittent aquatic habitats thrive both submerged and emerged. In order to outline the adaptive
characters of these two life forms photochemical efficiency of photosystem 2, leaf contents of chlorophyll (Chl) a and b, carotenoids (Car), anthocyanins (Ant), and UV-B absorbing compounds (UV-B abs), and root aerenchyma and arbuscular mycorrhizal
(AM) colonisation were studied in Glyceria fluitans, Gratiola officinalis, Ranunculus lingua, Teucrium scordium, Sium latifolium, Sparganium emersum, and Veronica anagallis-aquatica. Water level fluctuations did not exert a severe effect on photon harvesting efficiency. Submerged specimens had higher contents
of Car and Ant whereas higher contents of UV-B abs were found in emerged specimens indicating efficient protection against
the harmful effects of solar radiation. Roots of all species studied had extensive aerenchyma and were colonised by AM fungi,
which were significantly more abundant in emerged specimens. This is the first report on AM symbiosis in S. latifolium and S. emersum. 相似文献
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Matjaž Hren Špela Baebler Marjana Camloh Maja Kova Maja Ravnikar Jana Žel 《Acta Physiologiae Plantarum》2006,28(1):3-8
Natural resources of paclitaxel, an effective anticancer compound, were threatened with extinction soon after the discovery
of this valuable substance. Cell suspension cultures derived from different Taxus species have rapidly become an alternative source of paclitaxel and other taxanes. In this paper we provide some insight
into cell growth characteristics in cell suspension culture of Taxus x media cv. Hicksii, with emphasis on the effects of jasmonic acid (JA) on taxane production in cell lines with different initial taxane content.
Additionally cell growth characteristics of two cell lines was followed during cultivation of cell suspension culture of Taxus x media cv. Hicksii. Packed cell volume (PCV) was shown to be a reliable and efficient alternative for measuring cell growth instead of fresh
and dry weight. The initial total taxane content was screened in a number of cell lines, followed by observing the effect
of JA on cell mass and total taxane production of selected lines. We showed a great variability in initial taxane content
in different cell lines, which decreased during cell suspension maintenance. JA was shown to inhibit cell growth and increase
total taxane production (14 to 106 fold). 相似文献
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Nina Šraj-Kržič Paula PongracMaja Klemenc Aleš KladnikMarjana Regvar Alenka Gaberščik 《Aquatic Botany》2006
Several plant species with amphibious characteristics from intermittent aquatic habitats were examined for colonisation with arbuscular mycorrhizal fungi (AM), dark septate endophytes (DSE) and the ratio of aerenchyma in root tissue. We studied submerged specimens of Alisma plantago-aquatica, Mentha aquatica, Myosotis scorpioides, Oenanthe fistulosa, Gratiola officinalis, Glyceria fluitans, Sium latifolium and Teucrium scordium. In the first four, we also examined the emerged growth forms, which were grown under experimental conditions. Roots of all species were mycorrhizal and showed AM and DSE colonisation. The results suggest that AM colonisation may also be abundant in plants of aquatic environment. Arbuscules were not found in submerged specimens of M. aquatica, O. fistulosa and S. latifolium. The AM colonisation was generally higher in emerged specimens as compared to submerged ones. The aerenchyma ratio in root cross-sections ranged from 10 to 50% and in most cases did not differ between submerged and emerged specimens. No clear relationship between AM colonisation and aerenchyma ratio was recognized, while a positive correlation between AM and plant available phosphorous was established. 相似文献
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Vukelic S Stojadinovic O Pastar I Rabach M Krzyzanowska A Lebrun E Davis SC Resnik S Brem H Tomic-Canic M 《The Journal of biological chemistry》2011,286(12):10265-10275
Glucocorticoids (GCs) are known inhibitors of wound healing. In this study we report the novel finding that both keratinocytes in vitro and epidermis in vivo synthesize cortisol and how this synthesis regulates wound healing. We show that epidermis expresses enzymes essential for cortisol synthesis, including steroid 11 β-hydroxylase (CYP11B1), and an enzyme that controls negative feedback mechanism, 11β-hydroxysteroid dehydrogenase 2 (11βHSD2). We also found that cortisol synthesis in keratinocytes and skin can be stimulated by ACTH and inhibited by metyrapone (CYP11B1 enzyme inhibitor). Interestingly, IL-1β, the first epidermal signal of tissue injury, induces the expression of CYP11B1 and increases cortisol production by keratinocytes. Additionally, we found induction of CYP11B1 increased production of cortisol and activation of GR pathway during wound healing ex vivo and in vivo using human and porcine wound models, respectively. Conversely, inhibition of cortisol synthesis during wound healing increases IL-1β production, suggesting that cortisol synthesis in epidermis may serve as a local negative feedback to proinflammatory cytokines. Local GCs synthesis, therefore, may provide control of the initial proinflammatory response, preventing excessive inflammation upon tissue injury. Inhibition of GC synthesis accelerated wound closure in vivo, providing the evidence that modulation of cortisol synthesis in epidermis may be an important regulatory mechanism during wound healing. 相似文献
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Regvar M Eichert D Kaulich B Gianoncelli A Pongrac P Vogel-Mikus K Kreft I 《Journal of experimental botany》2011,62(11):3929-3939
Mature developed seeds are physiologically and biochemically committed to store nutrients, principally as starch, protein, oils, and minerals. The composition and distribution of elements inside the aleurone cell layer reflect their biogenesis, structural characteristics, and physiological functions. It is therefore of primary importance to understand the mechanisms underlying metal ion accumulation, distribution, storage, and bioavailability in aleurone subcellular organelles for seed fortification purposes. Synchrotron radiation soft X-ray full-field imaging mode (FFIM) and low-energy X-ray fluorescence (LEXRF) spectromicroscopy were applied to characterize major structural features and the subcellular distribution of physiologically important elements (Zn, Fe, Na, Mg, Al, Si, and P). These direct imaging methods reveal the accumulation patterns between the apoplast and symplast, and highlight the importance of globoids with phytic acid mineral salts and walls as preferential storage structures. C, N, and O chemical topographies are directly linked to the structural backbone of plant substructures. Zn, Fe, Na, Mg, Al, and P were linked to globoid structures within protein storage vacuoles with variable levels of co-localization. Si distribution was atypical, being contained in the aleurone apoplast and symplast, supporting a physiological role for Si in addition to its structural function. These results reveal that the immobilization of metals within the observed endomembrane structures presents a structural and functional barrier and affects bioavailability. The combination of high spatial and chemical X-ray microscopy techniques highlights how in situ analysis can yield new insights into the complexity of the wheat aleurone layer, whose precise biochemical composition, morphology, and structural characteristics are still not unequivocally resolved. 相似文献
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Roser Tolrà Paula Pongrac Charlotte Poschenrieder Katarina Vogel-Mikuš Marjana Regvar Juan Barceló 《Plant and Soil》2006,282(1-2):333-341
We investigated the hypothesis that continuous water application allows favorable and steady water content and hydraulic conductivity
in the root zone, thus enabling higher water potential in the soil–root interface (ψroot). Elevated ψroot increases transpiration (T) and prevents yield loss due to stomatal closure or to low root osmotic potential that develops in response to low ψroot. We assume further, that the advantage of continuous water application is more pronounced for young plants, where water uptake
per root length and competition on resources in the root system is higher. We investigated this hypothesis by examining the
average water content of the root zone and T as a function of time for sunflowers grown under varied irrigation frequencies experimentally and in a modeled simulations,
and by solving for the necessary effective root length and ψroot for each case. High frequency water application was shown to positively affect root water uptake efficiency and yield, especially
when plants were young. Irrigation frequency affected growth through the water content in the bulk soil (θsoil) which in turn affects ψroot. A low θsoil and coupled low hydraulic conductivity decreased T and yield. Moreover, a decreased θsoil caused low ψroot, inefficient allocation of energy and carbohydrates and eventual yield loss. It was likely that these phenomena were more
pronounced with young plants due to higher water uptake per root length. 相似文献