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681.
Chia-Chung Lee Deh-Ming Chang Kuo-Feng Huang Chun-Liang Chen Tsung-Chih Chen Yang Lo Jih-Hwa Guh Hsu-Shan Huang 《Bioorganic & medicinal chemistry》2013,21(22):7125-7133
A series of 2,7-diamidofluorenones were designed, synthesized, and screened by SRB assay. Some synthesized compounds exhibited antitumor activities in submicromolar range. Ten compounds (3a, 3b, 3c, 3g, 3j, 3l, 4a, 4h, 4i, and 4j) were also selected by NCI screening system and 3c (GI50 = 1.66 μM) appeared to be the most active agent of this series. Furthermore, 3c attenuated topoisomerase I-mediated DNA relaxation at low micromolar concentrations. These results indicated that fluorenones have potential to be further developed into anticancer drugs. 相似文献
682.
A glucomannan isolated from konjac flour was hydrolyzed with commercially available crude and purified cellulases. The following oligosaccharides were isolated from the hydrolyzate and identified: (a) 4-O-β-d-mannopyranosyl-d-monnose (b) 4-O-β-d-mannopyranosyl-d-glucose (c) O-β-d-mannopyranosyl-(1→4)-O-β-d-mannopyranosyl-(1→4)-d-mannose (d) O-β-d-mannopyranosyl-(1→4)-O-β-d-mannopyranosyl-(1→4)-d-glucose (e) O-β-d-mannopyranosyl-(1→4)-O-β-d-mannopyranosyl-(1→4)-O-β-d-mannopyranosyl-(1→4)-d-mannose (f) O-β-d-mannopyranosyl-(1→4)-O-β-d-mannopyranosyl-(1→4)-O-β-d-mannopyranosyl-(1→4)-d-glucose (g) O-β-d-mannopyranosyl-(1→4)-O-β-d-mannopyranosyl-(1→4)-O-β-d-mannopyranosyl-(1→4)-O-β-d-mannopyranosyl-(1→4)-d-glucose (h) 4-O-β-d-glucopyranosyl-d-glucose(cellobiose) (i) 4-O-β-d-glucopyranosyl-d-mannose (epicellobiose) (j) O-β-d-glucopyranosyl-(1→4)-O-β-d-mannopyranosyl-(1→4)-d-mannose. Of these saccharides, (h), (i) and (j) were isolated from the hydrolyzate by purified cellulase, while (g) was isolated from the hydrolyzate by crude cellulase. The others were all present in the hydrolyzates both by crude and by purified cellulases. 相似文献
683.
Akira Koiwai Fumi Mushiake Kazuhiko Ozeki 《Bioscience, biotechnology, and biochemistry》2013,77(2):381-386
Changes in the contents of nucleic acids and sugars in tobacco leaves during maturity stage and flue-curing were investigated. The content of RNA continued to decrease during both periods and is lower in lower leaves on the stalk. However, a temporary reverse trend was observed after topping. A sharp decrease after topping in ribonuclease activity was followed by an increase in RNA several days later, and thereafter soluble protein also increased temporarily in maturity stage.Sucrose, glucose and fructose decreased temporarily after topping and then increased gradually in the latter stage of maturity, followed by an abrupt increase in the yellowing stage of flue-curing. Minor sugars, i.e. maltose, ribose, mannose, galactose and xylose were determined quantitatively in tobacco leaves. However, these sugars have not shown any remarkable changes during maturity stage and flue-curing. 相似文献
684.
《Bioscience, biotechnology, and biochemistry》2013,77(11):2525-2527
The lichen substance, 16-O-acetyl-leucotylic acid (1), was isolated from an acetone extract of Myelochroa aurulenta and found to exhibit antiproliferative activity against HL-60 human leukemia cells. This is the first report on its anti-leukemia activity (EC50=21 μM) which is greater than that of leucotylic acid (2) and the structurally related anti-tumor agent, betulinic acid (4). 相似文献
685.
Tetsu Ando Sigeo Yoshida Sadahiro Tatsuki Nobutaka Takahashi 《Bioscience, biotechnology, and biochemistry》2013,77(5):1163-1165
Fusobacterium K-60, a ginsenoside Rb1-metabolizing bacterium, was isolated from human intestinal feces. From this Fusodobacterium K-60, a ginsenoside Rb1-metabolizing enzyme, β-glucosidase, has been purified. The enzyme was purified to apparent homogeneity by a combination of butyl-Toyopearl, hydroxyapatite ultragel, Q-Sepharose, and Sephacryl S-300 HR column chromatographies with a final specific activity of 1.52 μmol/min/mg. It had optimal activity at pH 7.0 and 40°C. The molecular mass of this purified enzyme was 320 kDa, with 4 identical subunits (80 kDa). The purified enzyme activity was inhibited by Ba++, Fe++, and some agents that modify cysteine residues. This enzyme strongly hydrolyzed sophorose, followed by p-nitrophenyl β-D-glucopyranoside, esculin, and ginsenoside Rb1. However, this enzyme did not change 20-O-β-D-glucopyranosyl-20(S)-protopanaxadiol (IH-901) to 20(S)-protopanaxadiol, while it weakly changed ginsenoside Rb1 to IH-901. These findings suggest that the Fusobacterial β-glucosidase is a novel enzyme transforming ginsenoside Rb1. 相似文献
686.
《Bioscience, biotechnology, and biochemistry》2013,77(7):1486-1491
RNase Po1 is a guanylic acid-specific ribonuclease (a RNase T1 family RNase) from Pleurotus ostreatus. We determined the cDNA sequence encoding RNase Po1 and expressed RNase Po1 in Escherichia coli. A comparison of the enzymatic properties of RNase Po1 and RNase T1 indicated that the optimum temperature for RNase Po1 activity was 20 °C higher than that for RNase T1. An MTT assay indicated that RNase Po1 inhibits the proliferation of human neuroblastoma cells (IMR-32 and SK-N-SH) and human leukemia cells (Jurkat and HL-60). Furthermore, Hoechst 33342 staining showed morphological changes in HL-60 cells due to RNase Po1, and flow cytometry indicated the appearance of a sub-G1 cell population. The extent of these changes was dependent on the concentration of RNase Pol. We suggest that RNase Po1 induces apoptosis in tumor cells. 相似文献
687.
《Bioscience, biotechnology, and biochemistry》2013,77(6):1186-1192
A chemical investigation of Digitalis purpurea seeds led to the isolation of three new cardenolide glycosides (1, 8 and 11), together with 12 known cardenolide glycosides (2–7, 9, 10 and 12–15). The structures of 1, 8 and 11 were determined by 1D and 2D NMR spectroscopic analyses and the results of an acid or enzymatic hydrolysis. The cytotoxic activity of the isolated compounds (1–15) against HL-60 leukemia cells was examined. Compounds 2, 9, 11 and 12 showed potent cytotoxicity against HL-60 cells with respective 50% inhibition concentration (IC50) values of 0.060, 0.069, 0.038, and 0.034 µM. Compounds 2, 9 and 11 also exhibited potent cytotoxic activity against HepG2 human liver cancer cells with respective IC50 values of 0.38, 0.79, and 0.71 µM. An investigation of the structure-activity relationship showed that the cytotoxic activity was reduced by the introduction of a hydroxy group at C-16 of the digitoxigenin aglycone, methylation of the C-3' hydroxy group at the fucopyranosyl moiety, and acetylation of the C-3' hydroxy group at the digitoxopyranoyl moiety. 相似文献
688.
Three strains recovered from mussels (F26), sewage (SW28-13T) and pork meat (F41T) were characterized as Arcobacter. They did not appear to resemble any known species on the basis of their 16S rDNA-RFLP patterns and the rpoB gene analyses. However, strains F26 and SW28-13T appeared to be the same species. The 16S rRNA gene sequence similarity of strains SW28-13T and F41T to the type strains of all other Arcobacter species ranged from 94.1% to 99.6% and 93.4% to 98.8%, respectively. Phenotypic characteristics and the DNA–DNA hybridization (DDH) results showed that they belonged to 2 new Arcobacter species. A multilocus phylogenetic analysis (MLPA) with the concatenated sequences of 5 housekeeping genes (gyrA, atpA, rpoB, gyrB and hsp60) was used for the first time in the genus, showing concordance with the 16S rRNA gene phylogenetic analysis and DDH results. The MALDI-TOF mass spectra also discriminated these strains as two new species. The names proposed for them are Arcobacter cloacae with the type strain SW28-13T (=CECT 7834T = LMG 26153T) and Arcobacter suis with the type strain F41T (=CECT 7833T = LMG 26152T). 相似文献
689.
690.
《Bioorganic & medicinal chemistry letters》2020,30(16):127288
Modifications at C6 and C7 positions of 3-cyanoquinolines 6 and 7 led to potent inhibitors of the ErbB family of kinases particularly against EGFRWT and Her4 enzymes in the radioisotope filter binding assay. The lead (4, SAB402) displayed potent dual biochemical activities with EGFRWT/Her4 IC50 ratio of 80 due to its potent inhibition of Her4 activity (IC50 0.03 nM), however, the selectivity towards activating mutations (EGFRL858R, EGFRex19del) was decreased. Inhibitor 4 also exhibited excellent growth inhibition in seven different cancer types and reduced cell viability in female NMRI nude mice in the intraperitoneally implanted hollow fibers which have been loaded with MOLT-4 (leukemia) and NCI-H460 (NSCLC) cells in a statistically significant manner. 相似文献