Water-insoluble condensed tannins content of young persimmon fruits-derived crude fibre relates to its bile acid-binding ability

In this study, we prepared crude fibre samples from young fruits of 10 persimmon (Diospyros kaki) cultivars and from young fruits of Japanese pear (Pyrus pyrifolia var. culta) and peach (Prunus persica) and compared their bile acid-binding abilities in?vitro. All crude fibre samples from young fruits of persimmon were able to bind to cholic acid in a 4?mM cholic acid solution, but crude fibre samples from young fruits of Japanese pear and peach did not show bile acid-binding ability. The bile acid-binding ability was strongly correlated with the water-insoluble condensed tannins content in crude fibre samples (r?=?0.909, p?相似文献   

Copolycondensations of bisphenols with aggregates of isophthalic acid and terephthalic acid activated by tosyl chloride/dimethylformamide/pyridine in different manners

A mixture of isophthalic acid (IPA) and terephthalic acid (TPA) was activated by a tosyl chloride/dimethylformamide/pyridine (Py) condensing agent in two steps via the treatment of a mixture of the initially activated IPA/TPA with additional TPA followed by the activation of TPA with the agent. The resulting mixture showed a solubility in Py different from that obtained by the activation of them all at once; the difference might be due to different structures of the aggregates of the activated IPA and TPA at the same composition of the diacids. The structures of the aggregates were evaluated on the basis of melting points and the IR spectra of a mixture of dimethyl esters of IPA and TPA produced by the quenching of the reaction mixtures with methanol. The mixture obtained by two‐step activation showed lower melting points and spectral changes due to enhanced associations of the esters with respect to the mixture prepared by the activation of them all at once. The aggregates were also examined in terms of the distributions of IPA and TPA in thermotropic copolyesters prepared from methylhydroquinone and chlorohydroquinone by their transition temperatures and ¹³C NMR. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3884–3892, 2001     

Facially Dispersed Polyhydride Cu9 and Cu16 Clusters Comprising Apex‐Truncated Supertetrahedral and Square‐Face‐Capped Cuboctahedral Copper Frameworks

By using a linear tetraphosphine, meso‐bis[(diphenylphosphinomethyl)phenylphosphino]methane (dpmppm), nona‐ and hexadecanuclear copper hydride clusters, [Cu₉H₇(μ‐dpmppm)₃]X₂ (X=Cl ( 1 a ), Br ( 1 b ), I ( 1 c ), PF₆ ( 1 d )) and [Cu₁₆H₁₄(μ‐dpmppm)₄]X₂ (X₂=I₂ ( 2 c ), (4/3) PF₆?(2/3) OH ( 2 d )) were synthesized and characterized. They form copper‐hydride cages of apex‐truncated supertetrahedral {Cu₉H₇}²⁺ and square‐face‐capped cuboctahedral {Cu₁₆H₁₄}²⁺ structures. The hydride positions were estimated by DFT calculations to be facially dispersed around the copper frameworks. A kinetically controlled synthesis gave an unsymmetrical Cu₈H₆ cluster, [Cu₈H₆(μ‐dpmppm)₃]²⁺ ( 3 ), which readily reacted with CO₂ to afford linear Cu₄ complexes with formate bridges, leading to an unprecedented hydrogenation of CO₂ into formate catalyzed by {Cu₄(μ‐dpmppm)₂} platform. The results demonstrate that new motifs of copper hydride clusters could be established by the tetraphosphine ligands, and the structures influence their reactivity.     

Simultaneous analysis of cardiac glycosides in blood and urine by thermoresponsive LC-MS-MS

A new thermoresponsive polymer separation column was applied to simultaneous analysis of four cardiac glycosides (CGs) being widely used for the treatment of arrhythmias and heart failure in human blood and urine. This column is composed of an N-isopropylacrylamide polymer, the surface of which undergoes a reversible alteration from hydrophilic to hydrophobic by changing temperature. The chromatographic separation and retention times can be easily be controlled by adjusting the column temperature. As the column temperature was changed from 50 to 10 °C over 8 min, five CGs, including deslanoside, digoxin, methyldigoxin, digitoxin, and digitoxigenin (internal standard) were better resolved. Using these LC conditions, we analyzed four CGs in human whole blood and urine simultaneously by liquid chromatography-tandem mass spectrometry (LC-MS-MS). Validation data as functions of recovery rates, linearity, accuracy, and precision were carefully tested; all were generally satisfactory. The detection limits for the four CGs in both matrices were 0.2–0.3 ng/mL. The method was applied to analysis of methyldigoxin and its main metabolite digoxin in whole blood and urine samples obtained from a deceased person in actual autopsy case. To our knowledge, this is the first report describing an LC-MS-MS method using a thermoresponsive column for analysis of drug(s). The inclusion of the thermoresponsive column in an LC-MS-MS technique seems to extend the possibility for simultaneous analysis of compounds of different properties, such as hydrophobic precursors and their hydrophilic metabolites in biological samples within limited analysis times.     

Overlapping chemical and genetic diversity in Ligularia lamarum and Ligularia subspicata. Isolation of ten new eremophilanes and a new seco-bakkane compound

Root chemicals and DNA sequences were analyzed for Ligularialamarum samples collected in Yunnan and Sichuan Provinces of China and the relationship between the plant and Ligulariasubspicata, its taxonomically closest species, was examined. Both species produce furanoeremophilanes and eremophilan-8-one derivatives as the major components. Eleven new compounds, including a new seco-bakkane compound, were isolated. The two species were found to harbor overlapping intra-specific diversities with respect to the chemicals and the DNA sequences.     

New eremophilanes from Farfugium japonicum

Eighteen new eremophilanes (dimeric lactones, lactams, carboxylic acid, methyl ester, tetranor- and dinor-ketones, furanoeremophilane, enoleremophilanolide, epoxyeremophilanolide, and hydroxy- or methoxyeremophilanolides) have been isolated from the methanol extract of fresh rhizomes of Farfugium japonicum (Compositae), and their structures have been determined on the basis of high-resolution 2D NMR and X-ray crystallographic analyses as well as by chemical transformations.     

The origin of aromatic solvent-induced shifts in 19F n.m.r.

Aromatic solvent-induced shifts (ASIS) in ¹⁹F n.m.r. spectra of several organic fluoro compounds have been determined in several solvents. ¹⁹F n.m.r. signals of unsaturated fluoro compounds in C₆F₆ and C₆H₆ show excess high field shifts corresponding to the term σ_c (solvent shift caused by chemical interactions). The mechanism of this shift is discussed in connection with the presence of an F-π interaction. A thermal study also supports this idea.     

Chimeric RNA Oligonucleotides with Triazole and Phosphate Linkages: Synthesis and RNA Interference

Chimeric RNA oligonucleotides with an artificial triazole linker were synthesized using solution‐phase click chemistry and solid‐phase automated synthesis. Scalable synthesis methods for jointing units for the chimeric structure have been developed, and after click‐coupling of the jointing units with triazole linkers, a series of chimeric oligonucleotides was prepared by utilizing the well‐established phosphoramidite method for the elongation. The series of chimeric 21‐mer oligonucleotides that possessed the triazole linker at different strands and positions allowed for a screening study of the RNA interference to clarify the preference of the triazole modifications in small‐interfering RNA molecules.