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61.
The contents of free phenolic acids and cinnamic acid were determined using an HPLC method in methanolic extracts from biomass
of Schisandra chinensis (Turcz.) Baill. (Chinese magnolia vine) at different stages of organogenesis, cultured in vitro on a few variants of Murashige
and Skoog (MS) medium, containing different concentrations of plant growth regulators 6-benzylaminopurine (BAP) and 1-naphthaleneacetic
acid (NAA) (from 0.1 to 3.0 mg/l) and in extracts from overground parts of plants growing in vivo. Six of 12 analysed compounds
were detected in all extracts: chlorogenic, p-coumaric, p-hydroxybenzoic, protocatechuic, salicylic and syringic acids. Total contents of the examined metabolites in biomass of shoot-differentiating
callus culture cultivated on six MS medium variants were dependent on concentrations of growth regulators in the media and
ranged from 14.90 to 60.05 mg/100 g d.w. Total contents of the compounds in biomass extracts from undifferentiating callus
culture maintained only on two of six MS medium variants were higher and amounted to 74.54 and 78.24 mg/100 g d.w. Maximum
total contents of phenolic acids in both types of in vitro cultures were greater than in fruits (55.73 mg/100 g d.w.) and
leaves (4.55 mg/100 g d.w.) of plants gowning in vivo. Chlorogenic acid and salicylic acid were the main compounds identified
in biomass extracts of shoot-differentiating callus cultures (max 22.60 and 21.17 mg/100 g d.w., respectively), while chlorogenic
acid (max 38.43 mg/100 g d.w.) and protocatechuic acid (max 20.95 mg/100 g d.w.) prevailed in the extracts from undifferentiating
callus cultures. Other compounds dominated in fruits, namely p-coumaric acid (23.36 mg/100 g d.w.) and syringic acid (14.96 mg/100 g d.w.). This is the first report on biochemical potential
of cells from S. chinensis in vitro cultures to produce the biologically active phenolic acids. These are the first results on the analysis of this
group of metabolites in overground parts of plants growing in vivo, too. 相似文献
62.
Halina D. Inerowicz 《Journal of inclusion phenomena and macrocyclic chemistry》2001,39(3-4):211-214
Novel chromogenic crown ethers having an intraannular azo and phenolic hydroxy subunits have been used as complexing reagents for alkali metal cations. The complex formation was studied by visible spectroscopy and formation constants were calculated. The most pronounced spectral changes were observed for lithium ion. 相似文献
63.
Dr. Hanna Jędrzejewska Dr. Ewelina Wielgus Dr. Sławomir Kaźmierski Halina Rogala Dr. Michał Wierzbicki Dr. Aneta Wróblewska Dr. Tomasz Pawlak Prof. Marek J. Potrzebowski Prof. Agnieszka Szumna 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(7):1558-1566
Mechanical grinding/milling can be regarded as historically the first technology for changing the properties of matter. Mechanically activated molecular units (mechanophores) can be present in various structures: polymers, macromolecules, or small molecules. However, only polymers have been reported to effectively transduce energy to mechanophores, which induces breakage of covalent bonds. In this paper, a second possibility is presented—molecular capsules as stress-sensitive units. Mechanochemical encapsulation of fullerenes in cystine-based covalent capsules indicates that complexation takes place in the solid state, despite the fact that the capsules do not possess large enough entrance portals. By using a set of solvent-free MALDI (sf-MALDI) and solid-state NMR (ss-NMR) experiments, it has been proven that encapsulation proceeds during milling and in this process hydrazones and disulfides get activated for breakage, exchange, and re-forming. The capsules are porous and therefore prone to collapse under solvent-free conditions and their conformational rigidity promotes the collapse by the breaking of covalent bonds. 相似文献
64.
The Raman profiles of the ν5 mode (802 cm?1) of cyclohexane, ν5 (723 cm?1) of cyclohexane-d12 and ν2 (992 cm?1) of benzene and its deuterated analogs have been measured as a function of concentration in the benzene—cyclohexane liquid system. The vibrational time correlation functions of cyclohexane in benzene solutions have been calculated by Fourier inversion of isotropic band contours. The concentration dependence of the experimental vibrational correlation times computed from the correlation functions and from the half width at half height have been compared with that predicted theoretically for various mechanisms of band broadening. We have tested the Fischer—Laubereau dephasing model and the Knapp—Fischer concentration-fluctuation model. We have found that the latter model reproduces well experimental data only for the ν2 mode of benzene in solution. 相似文献
65.
Marek Chmielewski Zbigniew KaŁuża Czesław Bełżecki Piotr SaŁanski Janusz Jurczak Halina Adamowicz 《Tetrahedron》1985,41(12):2441-2449
High-pressure (2+2)cycloaddition of toluene-4-sulphonyl isocyanate to glycals is examined. Reactions proceed regiospecifically to afford single products in case of all 3-substituted glycals. Upon heating or even after standing at room temperature adducts undergo retro-addition to give starting glycals. Various aspects of the cycloaddition are discussed, especially ret-ro-reaction and rearrangement of β-lactams to α,β-unsaturated amides. 相似文献
66.
Iga Zuba Halina Polkowska-Motrenko 《Journal of Radioanalytical and Nuclear Chemistry》2018,318(2):967-972
A radiochemical neutron activation analysis procedure was developed for the determination of trace amounts of gold in biological materials. The procedure was realized with irradiation of reference and test samples in a nuclear reactor, selective and quantitative separation of gold using inorganic MnO2 Resin and gamma-ray spectrometric measurement of 198Au. The method is characterized by a low limit of detection of gold at ng g?1 level. Results shows that the method can be applied to the determination of trace amounts of gold in tissues for medical research. 相似文献
67.
68.
Warner JH Watt AR Thomsen E Heckenberg N Meredith P Rubinsztein-Dunlop H 《The journal of physical chemistry. B》2005,109(18):9001-9005
Steady-state and time-resolved photoluminescence spectroscopy are used to examine the photoluminescent properties of nanocrystal-polymer composites consisting of colloidal PbS nanocrystals blended with poly(2-methoxy-5(2-ethylhexyloxy)-p-phenylene vinylene). Quenching of the emission from the conjugated polymer due to the PbS nanocrystals is observed along with band edge emission from the ligand capped PbS nanocrystals. A decrease in the photoluminescence lifetime of MEH-PPV is also observed in the thin film nanocrystal-polymer composite materials. Photoluminescence excitation spectroscopy of the PbS nanocrystal emission from the composite shows features attributed to MEH-PPV providing evidence of a F?rster transfer process. 相似文献
69.
70.
Structural Chemistry - Stacking interactions play an important role in stabilizing DNA and RNA secondary structure. To select a computational level to study the stacking interactions, both energy... 相似文献