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1.
We studied the simultaneous quantitative analysis of biologically active substances, such as nicotinic acid, trigonelline, caffeine, qunolinic acid and tannic acid and pyrogallic acid, in several roasted coffees by an HPLC/diode-array system with a home-made sol-gel and ODS-2 columns. A simple method for simultaneous quantitative analysis of biologically active substances in the coffee brew became feasible by an HPLC/diode-array system with a sol-gel column at a single wavelength of 210 nm. The most efficient condition of the Rs value was above 1.05 when two sol-gel columns were connected. In addition, the elution behavior of nicotinic acid in brew extracted from commercially available coffee beans suggests the thermal decomposition process during roasting, and indicated the maximum value for full city roasted coffee. 相似文献
2.
Hiroki Tomioka Kazuhiko Takai Koichiro Oshima Hitosi Nozaki Koshiro Toriumi 《Tetrahedron letters》1980,21(50):4843-4846
The title complex oxidizes primary and secondary alcohols to the corresponding carbonyl compounds. Stereoselective epoxidation of allylic alcohols is also described. 相似文献
3.
4.
Generation of chromioenamines by reduction of O-acetyloximes with chromium(II) and their application
Chromioenamines can be generated by treatment of O-acetyloximes with chromium(II) via two steps of one-electron reduction and successive isomerization, and the species react with aldehydes to give gamma-amino alcohols after reduction with LiAlH4. 相似文献
5.
Y Nomoto H Takai T Hirata M Teranishi T Ohno K Kubo 《Chemical & pharmaceutical bulletin》1991,39(1):86-90
A series of 1-(6,7-dimethoxy-4-quinazolinyl)piperidines carrying various 5-membered heterocycles at the 4-position was synthesized and examined for cardiotonic activity in anesthesized dogs. The (4-oxo-2-thioxo-3-imidazolindinyl)amino derivatives showed the most potent inotropic activity. Marked loss of activity was observed in the 2,4-dihydro-3-thioxo-3H-1,2,4-triazolyl, the 2,4-dihydro-3-oxo-3H-pyrazolyl and the (2,3-dihydro-2-thioxo-3H-1,3,4-thiadiazol-5-yl)amino derivatives. The synthesis and structure-activity relationships are discussed. 相似文献
6.
A rhenium complex, [ReBr(CO)3(thf)]2, catalyzes the reaction of an aromatic aldimine with an acetylene to give an indene derivative in a quantitative yield. The reaction proceeds via C-H bond activation, insertion of the acetylene, intramolecular nucleophilic cyclization, and reductive elimination. In contrast to ruthenium and rhodium catalysts, which are usually employed in this type of reaction, the rhenium catalyst promotes the intramolecular nucleophilic cyclization of the alkenylmetal species generated by insertion of the acetylene. 相似文献
7.
Jun-ichi Hibino Takashi Okazoe Kazuhiko Takai Hitosi Nozaki 《Tetrahedron letters》1985,26(45):5579-5580
An organometallic reagent prepared from CH2I2, Zn, and TiCl4 is effective for methylenation of the title ketones. 相似文献
8.
[reaction: see text] A rhenium complex, [ReBr(CO)(3)(thf)](2), catalyzed the intermolecular reactions of 1,3-dicarbonyl compounds with terminal acetylenes and gave the corresponding alkenyl derivatives in excellent yields. These reactions could apply to an intramolecular version and gave the corresponding cyclic compounds quantitatively. 相似文献
9.
Hashizaki K Taguchi H Itoh C Sakai H Abe M Saito Y Ogawa N 《Chemical & pharmaceutical bulletin》2005,53(1):27-31
Poly(ethylene glycol)-grafted liposomes (PEG-liposomes) were prepared from dipalmitoylphosphatidylcholine (DPPC) with various amounts of distearoyl-N-monomethoxy poly(ethylene glycol)-succinyl-phosphatidylethanolamines (DSPE-PEG) with PEG molecular weights of 1000, 2000, 3000 and 5000. The effects of DSPE-PEG concentration on the permeability of PEG-liposomes were investigated using carboxyfluorescein (CF). In the gel state, the CF leakage from PEG-liposomes was decreased with increasing mole fractions of DSPE-PEG for all PEG molecular weights. In the liquid-crystalline state, the CF leakage from PEG-liposomes containing DSPE-PEG1000 gradually increased with increasing mole fractions of DSPE-PEG, while that of PEG-liposomes whose molecular weight in PEG units was above 2000 rapidly decreased by the addition of DSPE-PEG. Furthermore, no effect of PEG molecular weight on CF leakage was observed. The relationship between the fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH) (or 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH)) and the mole fraction of DSPE-PEG for PEG-liposomes was also investigated. No significant changes in fluorescence polarization of DPH for liposomal bilayer membranes was observed in the gel and liquid-crystalline states due to the addition of DSPE-PEG, while that of TMA-DPH was decreased compared with that of liposomes without DSPE-PEG in both states. 相似文献
10.