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1.
《Bioscience, biotechnology, and biochemistry》2013,77(8):1563-1571
The olivil type of lignan, (2S,3R,4R)-4-benzyl-4- hydroxy-3-hydroxymethyl-2-(3,4-methylenedioxyphenyl)tetrahydrofuran, was stereoselectively synthesized from D-xylose. 相似文献
2.
《Bioscience, biotechnology, and biochemistry》2013,77(7):1559-1567
(+)-Magnostellin C, which is a tetrahydrofuran type of lignan bearing a chiral secondary benzylic hydroxy group, was stereoselectively synthesized from L-arabinose by using threo selective aldol condensation. 相似文献
3.
《Bioscience, biotechnology, and biochemistry》2013,77(9):1605-1608
The effects of free fatty acids on the selectivity and thermal properties of starch samples incorporating free fatty acids were examined by DSC. An analysis of the free fatty acid values incorporated into cassava starch and potato starch shows that myristic acid was the highest and linoleic acid was the lowest, while the free fatty acid values of corn starch were significantly higher than those of the other starches. DSC measurements on corn starch show an initial peak and another peak in a higher-temperature region, this second peak differing according to the incorporated free fatty acid. It is thus considered that the state of the complex of each free fatty acid with amylose might be better understood by observing the respective DSC characteristics. 相似文献
4.
5.
《Bioscience, biotechnology, and biochemistry》2013,77(9):1615-1616
A new derivative of sulfatide, 2-O-α-l-fucopyranosyl sulfatide, was synthesized. The compound inhibited the binding of HL-60 cells, which express sialyl Lewis X, to P- and L-selectin more than the corresponding non fucosylated compound. 相似文献
6.
《Bioscience, biotechnology, and biochemistry》2013,77(10):2144-2147
The new lignan glucoside, acutumoside (1), was isolated from Sinomenium acutum rhizomes together with nine known compounds (2–10). The structure of 1 was elucidated on the basis of extensive spectroscopic analyses, including two-dimensional nuclear magnetic resonance and chemical reactions. Compounds 2, 7, 8, and 10 displayed potential antiproliferative activity against A549, SK-OV-3, SK-MEL-2, and HCT-15 cell lines, while compound 1 showed weak activity against these human tumor cells. 相似文献
7.
Tadahiko Kajiwara Toshihiro Nakatomi Yasushi Sasaki Akikazu Hatanaka 《Bioscience, biotechnology, and biochemistry》2013,77(9):2099-2104
Optically active dictyopterenes A and B and their geometrical isomers were stereoselectively synthesized by condensation of acrolein with carboethoxymethyl dimethylsulfonium bromide and by the Wittig reaction between (+)-2-vinylcyclopropylcarbaldehyde, which was derived from partially resolved (+)-(1,S, 2R)-2-vinylcyclopropanecarboxylic acid, and phosphonium salts in liquid-solid two-phase systems using crown ethers. 相似文献
8.
An optically active key intermediate, methyl 2, 4-dideoxy-4-C-carboxymethylene-α-d-ribo-hexopyranoside 2′→3 lactone (XII), for the syntheses of optically active Thromboxanes was prepared from d-glucose. 相似文献
9.
《Bioscience, biotechnology, and biochemistry》2013,77(7):1238-1241
The new lignan derivative, erimopyrone, was isolated from the liverwort, Moerckia erimona. Its structure was established as [1R, 2S]-1(6-carboxy-2-oxo-2H-4-pyranyl)- 6,7-dihydroxy-1,2-dihydro-2,3-naphthalenedicarboxylic acid by spectroscopic methods. 相似文献
10.
《Bioscience, biotechnology, and biochemistry》2013,77(2):352-354
We report here a novel synthesis of optically active bishomotyrosine. The bishomotyrosine skeleton was constructed by using a Friedel-Crafts reaction between phenol and optically active N-Tfa-Glu(Cl)-OMe in triflic acid under the mild condition. Reduction and subsequent deprotection then afforded bishomotyrosine derivatives without any loss of optical purity. 相似文献
11.
《Bioscience, biotechnology, and biochemistry》2013,77(8):1718-1721
The inhibitory effect of (?)-, (+)-matairesinol and (?)-, (+)-secoisolariciresinol on the discoloration of dark muscle (chiai in Japanese) of two-year-old yellowtail (hamachi in Japanese) was evaluated by measuring the X and a* values. (?)-Matairesinol was most effective for retaining the red color of dark muscle in this experiment. 相似文献
12.
光学活性叔亮氨酸合成的研究进展 总被引:1,自引:1,他引:1
由于叔丁基的特殊结构和性质 ,叔亮氨酸是重要的医药中间体和不对称合成的手性诱导模板。本文综述了近年来光学活性的叔亮氨酸的合成研究及最新进展。 相似文献
13.
《Bioscience, biotechnology, and biochemistry》2013,77(5):1258-1260
The biocatalytic stereoselective hydrolysis of 2-hydroxy-3-nitropropionic acid esters was studied. Forty enzymes and three hundred microorganism strains were examined for their ability to hydrolyze ethyl 2-hydroxy-3-nitropropionic acid. Nocardia globerula IFO13150 gave n-butyl (R)-2-hydroxy-3-nitropropionate with a 92% enantiomeric excess (ee) and the corresponding carboxylic acid with a 92%ee, which was easily converted to (S)-isoserine, a useful β-amino acid. 相似文献
14.
DL-Glutamic acid has been resolved into optically active forms as the diastereoisomeric salt of optically active neutral amino acid amides, and the salt is easily converted to the sodium salt of the active forms. By resolution with L-tyrosinamide and L-leucinamide, sodium L-glutamate was obtained in 65 and 80 per cent yield respectively. Attempts to extend this method to resolution of DL-glutamic acid using L-phenylalaninamide as resolving agent resulted in poor yield of less pure D-glutamic acid.By the infrared spectroscopy and X-ray diffraction analysis it has been confirmed that the diastereoisomeric salts of L-leucinamide or L-tyrosinamide with L- or D-glutamic acid compose a combined salt structure in solid state, whereas L-phenylalaninamide with L- or D-glutamic acid does not compose a characteristic diastereoisomeric salt but rather the mechanical mixture of L-phenylalaninamide and L- or D-glutamate anion in solid state.In the previous study1), it was reported that L-leucinamide forms the characteristic diastereoisomeric salts with racemic N-acyl mono amino acids, most of which are fairly resolved into their antipodes. 相似文献
15.
《Bioscience, biotechnology, and biochemistry》2013,77(2):424-426
The mixed anhydride method was applied to synthesize O-aryl O-ethyl phenylphosphonothionate. The reaction of O, O-diethyl phosphorochloridate with O-ethyl phenylphosphonothioic acid afforded O, O-diethyl phosphoric O-ethyl phenylphosphonothioic anhydride in a good yield. This anhydride was converted to O-aryl O-ethyl phenylphosphonothionates by reacting with the appropriate sodium phenoxide. This esterification occurred without racemization and produced optically pure O-ethyl O-(4-nitrophenyl) phenylphosphonothionate (EPN) and O-(4-cyanophenyl) O-ethyl phenylphosphonothionate (cyanofenphos). 相似文献
16.
Yoshiki Sakata Hirohisa Suzuki Kuniharu Takenouchi 《Bioscience, biotechnology, and biochemistry》2013,77(12):816-823
The growth rate of the α-crystal of L-glutamic acid was measured under various degrees of supersaturation and temperatures. The rate constants and the activation energies for (0 0 1) and (1 1 1) faces were measured and the latter values were 6.7 and 11.5 kcal/mol, respectively. The controlling process of the α-crystal growth was investigated by comparison of Sherwood numbers of dissolution and crystallization, and the crystallization process was found to be controlled by the surface reaction. 相似文献
17.
Yoshiki Sakata 《Bioscience, biotechnology, and biochemistry》2013,77(6):355-361
The velocity of the α-β transition was measured in two cases, i.e., when α-crystals stayed in the saturated aqueous solution, and when they were left to stand in an air-bath at various temperatures ranging from 20° to 100°C. And it was deduced from the results of the measurement that this transition is due to the recrystallization of α-crystals into the β-form on the inner surfaces of the crystal and in the bulk of the solution, and the transition on the inner surfaces will be dominant, especially at the initial stage of the transition. 相似文献
18.
Sachio Kudo Takayuki Oritani Kyohei Yamashita 《Bioscience, biotechnology, and biochemistry》2013,77(9):2315-2319
Optically active tiraras-cycloheximide isomers such as cycloheximide [(2S,4S,6R,αR)-form (1)], naramycin B[(25,4S,6RαR)-form(4)], and new stereoisomers (2S,4S,6S,αS)-form (8) and (2S,4S,6R,αS)-from (9) were synthesized by an aldol condensation of trans-2,4-dimethyl-l-cyclohexanone (5b), with 4-(2-oxoethyl)-2,6-piperidinedione(6). The antimicrobial activity of trans- cycloheximide isomers (1, 4, 8, and 9) was examined against S. cerevisiae and P. oryzae. The stereoisomers 1 and 4 exhibited marked antimicrobial activity against both microorganisms as compared with their C- α-epimers 8 and 9. 相似文献
19.
Romualdo Caputo Annalisa Guaragna Giovanni Palumbo Silvana Pedatella 《Nucleosides, nucleotides & nucleic acids》2013,32(9-11):1739-1745
Abstract A ready asymmetric synthesis of 3′-oxa-4′-thionucleosides has been accomplished in three main steps from benzoyloxyethanal. The synthesis is characterized by high overall yield and appreciable enantiomeric excesses. It represents a general synthetic scheme to prepare a wide range of heterosubstituted sulfur-containing nucleoside analogues. 相似文献
20.
亚麻木酚素的微波辅助提取工艺研究 总被引:11,自引:0,他引:11
采用微波辅助提取法从脱脂亚麻籽壳中提取亚麻木酚素,以磷钼酸显色的方法定量测定亚麻木酚素,通过单因素试验、中心组合试验及响应面分析,确定微波辅助提取的最优工艺条件为:乙醇浓度40.9%(v/v)、液固比21.9:1(mL/g)、超声处理5 min进行预浸、辐照时间90.5 s、微波功率为130 W。与常规溶剂提取法和索氏提取方法相比,微波辅助提取法显著提高了亚麻木酚素的得率,大大缩短了提取时间,并节省了能耗。 相似文献