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991.
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994.
Antitumor-promoting constituents from Chaenomeles sinensis KOEHNE and their activities in JB6 mouse epidermal cells 总被引:2,自引:0,他引:2
Gao H Wu L Kuroyanagi M Harada K Kawahara N Nakane T Umehara K Hirasawa A Nakamura Y 《Chemical & pharmaceutical bulletin》2003,51(11):1318-1321
Primary screening of antitumor-promoting activity using soft agar colony assays with JB6 cells was employed to isolate 22 compounds from Chaenomeles sinensis KOEHNE. These compounds were lyoniresinol-2a-O-alpha-L-rhamnopyranoside (1), lyoniresinol-2a-O-beta-D-glucopyranoside (2), aviculin (3), betulinic acid (4), betulin (5), 3-O-(E)-p-coumaroylbetulin (6), 3-O-(E)-caffeoylbetulin (7), 3-O-(Z)-p-coumaroylbetulin (8), 3-O-(E)-caffeoyllupeol (9), alphitolic acid (10), sorbikortal II (11), tormentic acid (12), euscaphic acid (13), corosolic acid (14), maslinic acid (15), erythrodiol (16), 1-beta-D-glucopyranosyloxy-3,4,5-trimethoxybenzene (17), avicularin (18), 7-O-beta-D-glucopyranosylkaempferol (19), 5-O-beta-D-glucopyranosylgenistein (20), 7-O-beta-D-glucopyranosylgenistein (21), epicatechin (22), and beta-sitosterol (23) and were identified using spectral data such as MS, (1)H- and (13)C-NMR. Compound 1, having a rhamnosyl group, showed greater activity than 2, having a glucosyl group, and 3, which was a bis-demethoxy derivative of 1. Betulinic acid (4), having a C-28 carboxyl group, 3-O-(E)-caffeoylbetulin (7), and tormentic acid (12) showed more potent activity than betulin (5), which has a C-28 hydroxymethyl group. 相似文献
995.
Harada Layse H. P. da Costa Aline C. Filho Rubens Maciel 《Applied biochemistry and biotechnology》2002,98(1-9):1009-1023
The objective of this work was to develop a model for an extractive ethanol fermentation in a simple and rapid way. This model
must be sufficiently reliable to be used for posterior optimization and control studies. A hybrid neural model was developed,
combining mass and energy balances with neural networks, which describe the process kinetics. To determine the best model,
two structures of neural networks were compared: the functional link networks and the feedforward neural networks. The two
structures are shown to describe well the process kinetics, and the advantages of using the functional link networks are discussed. 相似文献
996.
Treatment of a tetrahydrofuran solution of CrCl2(thf) with Na(hfac), hfac = 1,1,1,5,5,5-hexafluoroacetylacetonate, followed by crystallization from diethyl ether, affords the six-coordinate chromium(II) complex Cr(hfac)2(thf)2. The crystal structures of Cr(hfac)2(thf)2 and the chromium(III) complex Cr(hfac)3 have been determined by single-crystal X-ray diffraction. Cr(hfac)2(thf)2 adopts a trans octahedral geometry, in which the Cr–O(hfac) and Cr–O(thf) distances are 1.936(3) and 2.019(6) Å, respectively. Cr(hfac)3 is an octahedral compound with a Cr–O distance of 1.943(5) Å. Structural comparisons with related molecules are given. 相似文献
997.
Mitsuru Ueda Toshiaki Harada Shigeto Aoyama Yoshio Imai 《Journal of polymer science. Part A, Polymer chemistry》1981,19(5):1061-1071
New active diesters and diamides derived from 3-hydroxy-1,2-benzisoxazole were prepared for use in polyamide synthesis. The active esters and amides reacted readily with amines to give quantitative yields of amides. The high reactivity to these active esters and amides was discussed in relation to the electon-withdrawing effect of the leaving group and intramolecular general-base catalysis. Solution polycondensation of new active diesters and diamides with aliphatic and aromatic diamines proceeded slowly under mild conditions to produce polyamides with inherent viscosities up to 1.5. 相似文献
998.
Yoshihisa Kurasawa Akiko Takano Kazuho Harada Atsushi Takada Ho Sik Kim Yoshihisa Okamoto 《Chemistry of Heterocyclic Compounds》1995,31(9):1088-1095
The reaction of 6-chloro-2-(1-methylhydrazino)quinoxaline 4-oxide (1) with -diketone abd -ketoesters gave the dihydropyridazino[3,4-b]quinoxalines (IIIa-d), which were found to exist as the 1,5-dihydro form in solution and solid state by NMR spectoscopy and x-ray analysis.Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1245–1252, September, 1995. 相似文献
999.
N Hazemoto M Harada N Komatsubara M Haga Y Kato 《Chemical & pharmaceutical bulletin》1990,38(3):748-751
pH-induced destabilization, aggregation and fusion of liposomes composed of phosphatidylethanolamine (PE) and various fatty acid were studied. Destabilization was examined as a fluorescent change caused by leakage of coencapsulated aminonaphthalene-3,6,8-trisulfonic acid (ANTS) and N,N-p-xylylenebispyridinium bromide (DPX). Fusion was monitored by two different methods, that is, intermixing assay of internal aqueous contents of liposomes, and lipid dilution assay of liposomes labeled with fluorescent phospholipids. Contents leakage from liposomes was observed by lowering the pH, and pH where the leakage began depended on fatty acid used. Fifty percent leakage of contents from PE liposomes containing alpha-hydroxypalmitic acid or alpha-hydroxy-stearic acid was observed at pH 5.5, that from liposomes containing stearic acid or palmitic acid was observed at pH 6.5-6.7, and that from ricinoleic acid at pH 7.2. Aggregation and fusion of the respective liposomes also occurred at a similar pH region. These results were interpreted by the notion that the protonation of the fatty acid triggers a series of pH-sensitive events. The liposomes developed in this study may be useful as a drug carrier which could release the contents in response to pH changes in their environment. 相似文献
1000.
Tetsuo Yamazaki Ryoichi Suzuki Toshiyuki Ohdaira Tomohisa Mikado Yoshinori Kobayashi 《Radiation Physics and Chemistry》1997,49(6):651-659
Slow positron beam is quite useful for non-destructive material research. At the Electrotechnical Laboratory (ETL), an intense slow positron beam line has been constructed by exploiting an electron linac in order to carry out various experiments on material analysis. The beam line can generate pulsed positron beams of variable energy and variable pulse period. Various capabilities of the intense pulsed positron beam is presented, based on the experience at the ETL, and the prospect for the future is discussed. 相似文献