stilbene Dotaz Zobrazit nápovědu
BACKGROUND: Fallopia japonica and its hybrid, F. xbohemica, due to their fast spread, are famous as nature threats rather than blessings. Their fast growth rate, height, coverage, efficient nutrient translocation between tillers and organs and high phenolic production, may be perceived either as dangerous or beneficial features that bring about the elimination of native species or a life-supporting source. To the best of our knowledge, there have not been any studies aimed at increasing the targeted production of medically desired compounds by these remarkable plants. We designed a two-year pot experiment to determine the extent to which stilbene (resveratrol, piceatannol, resveratrolosid, piceid and astringins) and emodin contents of F. japonica, F. sachalinensis and two selected F. xbohemica clones are affected by soil nitrogen (N) supply, leaf damage and mycorrhizal inoculation. RESULTS: 1) Knotweeds are able to grow on substrates with extremely low nitrogen content and have a high efficiency of N translocation. The fast-spreading hybrid clones store less N in their rhizomes than the parental species. 2) The highest concentrations of stilbenes were found in the belowground biomass of F. japonica. However, because of the high belowground biomass of one clone of F. xbohemica, this hybrid produced more stilbenes per plant than F. japonica. 3) Leaf damage increased the resveratrol and emodin contents in the belowground biomass of the non-inoculated knotweed plants. 4) Although knotweed is supposed to be a non-mycorrhizal species, its roots are able to host the fungi. Inoculation with mycorrhizal fungi resulted in up to 2% root colonisation. 5) Both leaf damage and inoculation with mycorrhizal fungi elicited an increase of the piceid (resveratrol-glucoside) content in the belowground biomass of F. japonica. However, the mycorrhizal fungi only elicited this response in the absence of leaf damage. Because the leaf damage suppressed the effect of the root fungi, the effect of leaf damage prevailed over the effect of the mycorrhizal fungi on the piceid content in the belowground biomass. CONCLUSIONS: Two widely spread knotweed species, F. japonica and F. xbohemica, are promising sources of compounds that may have a positive impact on human health. The content of some of the target compounds in the plant tissues can be significantly altered by the cultivation conditions including stress imposed on the plants, inoculation with mycorrhizal fungi and selection of the appropriate plant clone.
- MeSH
- biomasa MeSH
- dusík metabolismus MeSH
- emodin metabolismus MeSH
- listy rostlin chemie účinky léků MeSH
- mykorhiza růst a vývoj MeSH
- oddenek chemie mikrobiologie MeSH
- Polygonum chemie růst a vývoj mikrobiologie MeSH
- průmyslová hnojiva MeSH
- půda chemie MeSH
- roční období MeSH
- stilbeny metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Klíčová slova
- cytotoxicita,
- MeSH
- apoptóza * účinky léků MeSH
- inhibitory kaspas MeSH
- kaspasa 3 * MeSH
- neutrofily účinky léků MeSH
- stilbeny * MeSH
- techniky in vitro MeSH
- výzkum MeSH
- zánět MeSH
- Publikační typ
- práce podpořená grantem MeSH
A detailed kinetic study based on steady-state and pre-steady-state measurements is described for the highly enantioselective epoxide hydrolase Kau2. The enzyme, which is a member of the α/β-hydrolase fold family, preferentially reacts with the (S,S)-enantiomer of trans-stilbene oxide (TSO) with an E value of ∼200. The enzyme follows a classical two-step catalytic mechanism with formation of an alkyl-enzyme intermediate in the first step and hydrolysis of this intermediate in a rate-limiting second step. Tryptophan fluorescence quenching during TSO conversion appears to correlate with alkylation of the enzyme. The steady-state data are consistent with (S,S) and (R,R)-TSO being two competing substrates with marked differences in k(cat) and K(M) values. The high enantiopreference of the epoxide hydrolase is best explained by pronounced differences in the second-order alkylation rate constant (k2/K(S)) and the alkyl-enzyme hydrolysis rate k3 between the (S,S) and (R,R)-enantiomers of TSO. Our data suggest that during conversion of (S,S)-TSO the two active site tyrosines, Tyr(157) and Tyr(259), serve mainly as electrophilic catalysts in the alkylation half-reaction, polarizing the oxirane oxygen of the bound epoxide through hydrogen bond formation, however, without fully donating their hydrogens to the forming alkyl-enzyme intermediate.
- MeSH
- aktivace enzymů MeSH
- chemické modely * MeSH
- epoxid hydrolasy chemie ultrastruktura MeSH
- katalýza MeSH
- kinetika MeSH
- konformace proteinů MeSH
- simulace molekulového dockingu * MeSH
- stabilita enzymů MeSH
- stilbeny chemie MeSH
- substrátová specifita MeSH
- vazba proteinů MeSH
- vazebná místa MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Klíčová slova
- pterostilben,
- MeSH
- aktivace neutrofilů účinky léků MeSH
- antioxidancia MeSH
- lidé MeSH
- neutrofily * enzymologie MeSH
- oxidační stres imunologie účinky léků MeSH
- peroxidasa MeSH
- proteinkinasa C MeSH
- Pterocarpus MeSH
- reaktivní formy kyslíku škodlivé účinky MeSH
- stilbeny * farmakologie chemie MeSH
- superoxidy * škodlivé účinky MeSH
- techniky in vitro MeSH
- výzkum MeSH
- zánět prevence a kontrola MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
Stilbeny patří do malé skupiny sekundárních metabolitů syntetizovaných fenyl -propanoidovou cestou. Vyskytují se u několika druhů rostlin a hrají důležitou roli při reakci rostlin na biotický a abiotický stres. Mnoho stilbenů jsou antimikrobiální sloučeniny, které jsou syntetizovány z důvodu obrany rostlin proti mikrobiálním patogenům a býložravcům, a jsou klasifikovány jako fytoalexiny. Do této skupiny látek patří např. resveratrol, pterostilben a pinosylvin. Vzhledem k tomu, že rezistence mikroorganismů k antibiotikům se stává celosvětovým problémem, moderní medicína se stále snaží o vývoj nových léků, modifikaci stávajících struktur nebo zvýšení biologické aktivity antibiotik přidáním různých antimikrobiálních látek. Stilbeny mohou být potenciálními látkami při léčbě mikrobiálních infekcí a mají také široký potenciál v léčbě jiných civilizačních chorob
Stilbenes are a small family of plant secondary metabolites derived from the phenylpropanoid pathway. They are produced in a several plant species and play an important role in plant responses to various biotic and abiotic stresses. Many stibelines are antimicrobial compounds synthesized in response to microbial pathogen or herbivore attack and they are classified as phytoalexins. Resveratrol, pterostilbene and pinosylvine belong to this group of substances. Since the antibiotic resistance has become a worldwide problem, the modern medicine is still trying to develop new drugs, to modify existing structures or to increase the biological activity of antibiotics by adding various antimicrobial agents. Stilbenes might be potential agents in the treatment of microbial infections and they also have a wide potential in other civilizational diseases treatment.
- Klíčová slova
- pterostilben, pinosylvin,
- MeSH
- antibakteriální látky MeSH
- antifungální látky MeSH
- lidé MeSH
- resveratrol MeSH
- stilbeny * klasifikace terapeutické užití MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
The constitutive androstane receptor(CAR) activation is connected with mitogenic effects leading to liver hyperplasia and tumorigenesis in rodents. CAR activators, including phenobarbital, are considered rodent non-genotoxic carcinogens. Recently, trans-3,4,5,4´-tetramethoxystilbene(TMS), a potential anticancer drug (DMU-212), have been shown to alleviate N-nitrosodiethylamine/phenobarbital-induced liver carcinogenesis. We studied whether TMS inhibits mouse Car to protect from the PB-induced tumorigenesis. Unexpectedly, we identified TMS as a murine CAR agonist in reporter gene experiments, in mouse hepatocytes, and in C57BL/6 mice in vivo. TMS up-regulated Car target genes Cyp2b10, Cyp2c29 and Cyp2c55 mRNAs, but down-regulated expression of genes involved in gluconeogenesis and lipogenesis. TMS did not change or down-regulate genes involved in liver proliferation or apoptosis such as Mki67, Foxm1, Myc, Mcl1, Pcna, Bcl2, or Mdm2, which were up-regulated by another Car ligand TCPOBOP. TMS did not increase liver weight and had no significant effect on Ki67 and Pcna labeling indices in mouse liver in vivo. In murine hepatic AML12 cells, we confirmed a Car-independent proapoptotic effect of TMS. We conclude that TMS is a Car ligand with limited effects on hepatocyte proliferation, likely due to promoting apoptosis in mouse hepatic cells, while controlling Car target genes involved in xenobiotic and endobiotic metabolism.
- MeSH
- antikarcinogenní látky metabolismus farmakologie MeSH
- apoptóza účinky léků MeSH
- aromatické hydroxylasy genetika metabolismus MeSH
- buňky Hep G2 MeSH
- glukoneogeneze účinky léků genetika MeSH
- hepatocyty účinky léků metabolismus patologie MeSH
- játra účinky léků metabolismus MeSH
- lidé MeSH
- lipogeneze účinky léků genetika MeSH
- myši inbrední C57BL MeSH
- nádory jater enzymologie genetika patologie prevence a kontrola MeSH
- proliferace buněk účinky léků MeSH
- pyridiny farmakologie MeSH
- receptory cytoplazmatické a nukleární agonisté genetika metabolismus MeSH
- regulace genové exprese enzymů účinky léků MeSH
- rodina 2 cytochromů P450 genetika metabolismus MeSH
- signální transdukce účinky léků MeSH
- simulace molekulového dockingu MeSH
- steroidhydroxylasy genetika metabolismus MeSH
- stilbeny metabolismus farmakologie MeSH
- vazba proteinů MeSH
- vazebná místa MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Grape cane, leaves and grape marc are waste products from viticulture, which can be used to obtain secondary stilbene derivatives with high antioxidant value. The presented work compares several extraction methods: maceration at laboratory temperature, extraction at elevated temperature, fluidized-bed extraction, Soxhlet extraction, microwave-assisted extraction, and accelerated solvent extraction. To obtain trans-resveratrol, trans-ε-viniferin and r2-viniferin from grape cane of the V. vinifera variety Cabernet Moravia, various conditions were studied: different solvents, using powdered versus cut cane material, different extraction times, and one-step or multiple extractions. The largest concentrations found were 6030 ± 680 µg/g dry weight (d.w.) for trans-resveratrol, 2260 ± 90 µg/g d.w. for trans-ε-viniferin, and 510 ± 40 µg/g d.w. for r2-viniferin. The highest amounts of stilbenes (8500 ± 1100 µg/g d.w.) were obtained using accelerated solvent extraction in methanol.
- MeSH
- časové faktory MeSH
- chemická frakcionace metody MeSH
- hole * MeSH
- nukleární magnetická rezonance biomolekulární MeSH
- polyfenoly chemie izolace a purifikace MeSH
- rostlinné extrakty chemie izolace a purifikace MeSH
- rozpouštědla MeSH
- stilbeny chemie izolace a purifikace MeSH
- teplota MeSH
- Vitis chemie MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Resveratrol and closely related stilbenoids belong to the most intensively studied biologically active compounds. This interest evoked several attempts to prepare such compounds in a convenient synthetic way. Our approach allowed obtaining largely methoxystilbenes, formed as E-isomers only (using Wittig–Horner synthesis as the key step), which were further demethylated by boron tribromide. The hydroxymethoxystilbenes (e.g. pterostilbene) were prepared using isopropyl protection, later selectively deprotected by boron trichloride. The method is suitable for preparing such compounds in a large amount. Effects of the obtained stilbene derivatives on immunobiological responses triggered by lipopolysacharide and interferon-? were tested under in vitro conditions. Namely production of nitric oxide (NO) was investigated, and relation between the molecular structure and immunobiological activity was assessed.
