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排序方式: 共有155条查询结果,搜索用时 62 毫秒
1.
Yu-Chia Chang Chih-Chao Chiang Yuan-Shiun Chang Jih-Jung Chen Wei-Hsien Wang Lee-Shing Fang Hsu-Ming Chung Tsong-Long Hwang Ping-Jyun Sung 《Marine drugs》2020,18(11)
Two previously undescribed caryophyllane-related sesquiterpenoids, antipacids A (1) and B (2), with a novel bicyclo[5.2.0] core skeleton, and known compound clovane-2β,9α-diol (3), along with rumphellolide L (4), an esterified product of 1 and 3, were isolated from the organic extract of octocoral Rumphella antipathes. Their structures, including the absolute configurations were elucidated by spectroscopic and chemical experiments. In vivo anti-inflammatory activity analysis indicated that antipacid B (2) inhibited the generation of superoxide anions and the release of elastase by human neutrophils, with IC50 values of 11.22 and 23.53 μM, respectively, while rumphellolide L (4) suppressed the release of elastase with an IC50 value of 7.63 μM. 相似文献
2.
Summary The somatic karyotype and meiotic chromosome behavior were studied in an 18-chromosome B1 plant derived from backcrossing a triploid (Brassica napus x B. oleracea ssp. capitata) F1 hybrid to cabbage. It is considered that cabbage chromosomes no. 1 and no. 7 were substituted by two shorter B. napus chromosomes. Meiotic disturbances were more apparent during the late stages of second division. Seed fertility of this plant was largely restored in the second backcrosses with both cabbage and broccoli. 18-chromosome B2 plants resistant to race 2 of Plasmodiophora brassicae were recovered among the progenies.Contribution no. J. 725 from the Research Station, Research Branch, Agriculture Canada, St-Jean, Québec J3B 6Z8. 相似文献
3.
Chung CP Hsu CY Lin JH Kuo YH Chiang W Lin YL 《Journal of agricultural and food chemistry》2011,59(4):1185-1194
Two new lactams, coixspirolactam D (1) and coixspirolactam E (2), and a new spiroenone, coixspiroenone (3), together with seven known compounds, coixspirolactam A (4), coixspirolactam B (5), coixspirolactam C (6), coixlactam (7), coixol (8), ethyl dioxindole-3-acetate (9), and isoindol-1-one (10), and two neolignans, zhepiresionol (11) and ficusal (12), were isolated from the bioactive subfraction of adlay bran ethanolic extract (ABE). Compounds 9 and 10 are the first isolates from natural resources. The structures of new compounds were identified by spectroscopic methods, including infrared (IR) spectrum, 1D and 2D nuclear magnetic resonance (NMR), and mass spectrum (MS). All of the isolated compounds were tested for antiproliferative effects on MCF-7, MDA-MB-231, and T-47D cells. Results showed that compounds 1, 3, 4, 6, and 7 at 50 μM significantly inhibited MCF-7 cell proliferation by 30.2, 19.2, 21.0, 13.5, and 32.4%, respectively; compounds 2, 4, and 7 significantly inhibited T-47D cells at 50 μM by 20.7, 24.8, and 28.9%; and compounds 1, 2, and 12 significantly inhibited MDA-MB-231 cells at 50 μM by 47.4, 25.3, and 69.3%, respectively. In conclusion, ABE has antiproliferative activities, and this effect is partially related to the presence of lactams and spiroenone. 相似文献
4.
Kuo CC Chiang W Liu GP Chien YL Chang JY Lee CK Lo JM Huang SL Shih MC Kuo YH 《Journal of agricultural and food chemistry》2002,50(21):5850-5855
An activity-directed fractionation and purification process was used to identify the antioxidative components of adlay hulls. Hulls of adlay (Coix lachryma-jobi L. var. ma-yuen Stapf) were extracted with methanol and then separated into water, 1-butanol, ethyl acetate, and hexane fractions. The 1-butanol-soluble fraction exhibited greater capacity to scavenge 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radicals when compared with fractions soluble in water, ethyl acetate, and hexane phases. The 1-butanol fraction was then subjected to separation and purification using Diaion HP-20 chromatography, silica gel chromatography, and HPLC. Six compounds showing strong antioxidant activity were identified by spectroscopic methods ((1)H NMR, (13)C NMR, IR, and MS) and by comparison with authentic samples to be coniferyl alcohol (1), syringic acid (2), ferulic acid (3), syringaresinol (4), 4-ketopinoresinol (5), and a new lignan, mayuenolide (6). 相似文献
5.
Hsu TC Chiang SY Wu JH Tsai CC Huang CY Chen YC Tzang BS 《Journal of agricultural and food chemistry》2008,56(20):9685-9691
Cholesterol-rich diets are known to cause hepatic apoptosis, which has been associated with the pathogenesis of systemic lupus erythematosus (SLE). However, the mechanisms and treatments for hepatic apoptosis in SLE are poorly understood. To clarify the effects of taurine on hepatic apoptosis in SLE, NZB/W F1 mice received control, cholesterol, and cholesterol/taurine diets. Significant reductions of caspase-3 activity, TUNEL-positive cells, and Fas- and mitochondrial- dependent apoptosis were detected in liver from the cholesterol/taurine group as compared to the cholesterol group. Moreover, significant increases of phosphorylated AKT, NF-kappaB (p65), and ERK1/2 proteins were detected in liver from the cholesterol/taurine group as compared to the cholesterol group. In contrast, a significant reduction of phosphorylated p38 protein was observed in the cholesterol/taurine group. These experimental results demonstrated positive effects of taurine against hepatic apoptosis in NZB/W F1 mice fed a high-cholesterol diet and suggested the therapeutic potential of taurine in SLE. 相似文献
6.
Altering the substrate specificity of Candida rugosa LIP4 by engineering the substrate-binding sites
Lee LC Chen YT Yen CC Chiang TC Tang SJ Lee GC Shaw JF 《Journal of agricultural and food chemistry》2007,55(13):5103-5108
Candida rugosa (formerly Candida cylindracea) lipase (CRL) is an important industrial enzyme that is widely used in biotechnological applications such as the production of fatty acids and the synthesis of various esters. CRL comprises at least seven isozymes (LIP1-LIP7), which share a similar amino acid sequence but with different specificities for substrates. Previously, LIP4 was reported to have higher esterase activity toward long acyl-chain ester and lower lipase activity toward triglycerides. A296 and V344 of LIP4 were predicted to play decisive roles in its substrate specificity. In this study, site-specific saturation mutagenesis has been employed to study the substrate specificity of LIP4. Point mutations were separately introduced into A296 and V344 positions using degenerate primer sets containing 32 codons to generate two libraries of variants. LIP4 variants were heterologously expressed in the yeast Pichia pastoris. A specific plate assay was used to identify lipase-producing P. pastoris clones in a medium containing tributyrin. LIP4 variants with high activity toward short fatty acyl-chain triglyceride (tributyrin) were screened. Specificity analysis and biochemical characterization indicated that the recombinant variants A296I, V344Q, and V344H had properties remarkably different from those of wild-type LIP4. All three variant enzymes had significantly higher specific activities toward tributyrin than LIP4. In addition to short-chain triglyceride, A296I and V344Q also improved hydrolytic activities of triglycerides toward medium- and long-chain triglycerides tested. The results suggested that A296 played an important role in lipase activity and high-temperature dependence of LIP4, whereas it had no effect on the chain-length specificity in lipolytic reaction. The V344 residue had a significant effect on the substrate chain-length specificity of LIP4. 相似文献
7.
8.
Yao HT Lin JH Chiang MT Chiang W Luo MN Lii CK 《Journal of agricultural and food chemistry》2011,59(8):4306-4314
Adlay ( Coix lachryma-jobi L. var. ma-yuen Stapf) is a grass crop and is reported to protect against various diseases such as cancer. To investigate the effect of the ethanolic extract of adlay bran (ABE) on drug-metabolizing enzymes and glutathione-related antioxidant enzymes in rats, three groups of eight male Sprague-Dawley rats each were fed a control diet or a diet containing 5 or 10% ABE for 4 weeks. Significant decreases in microsomal cytochrome P-450 (CYP) 1A1-catalyzed ethoxyresorufin O-deethylation, CYP2C-catalyzed diclofenac 4-hydroxylation, CYP2D-catalyzed dextromethorphan O-demethylation, and CYP3A-catalyzed testosterone 6β-hydroxylation in the liver and CYP1A1-catalyzed ethoxyresorufin O-deethylation in the lungs of rats fed ABE were observed. Immunoblot analyses also showed decreases of CYP1A1, 1A2, 2C6, 2C11, 2D1, 2E1, 3A1, and 3A2 in the liver and CYP1A1 in the lungs. Furthermore, rats fed the 10% ABE diet had a higher glutathione content and glutathione peroxidase, glutathione reductase, and glutathione S-transferase activities in the lungs, but such an increase was not noted in the liver. Inhibition of various CYP-catalyzed enzyme reactions by ABE in rat and human liver microsomes had also been shown. The results of this study indicate that ABE feeding may suppress CYP enzyme activities and CYP protein expression in the liver and lungs of rats. Moreover, the increase of the antioxidant potential by ABE is tissue-specific. 相似文献
9.
Tsung Ming Tsao Yue Ming Chen Hwo Shuenn Sheu Shung Yao Zhuang Ping Hua Shao Hua Wen Chen Kai Shuan Shea Ming Kuang Wang Yen Horng Shau Kai Yin Chiang 《Journal of Soils and Sediments》2012,12(7):1054-1065
Purpose
Information on the physicochemical properties, mineral species and micromorphology of lateritic soils and gravel soil layers in paleo-environmental soil profile is severely lacking. Red soil profile of the Taoyuan terrace was employed to demonstrate its different extents of lateritic weathering. The objectives of this study were to compare the physicochemical properties of lateritic soils and gravel soil layers and identify using conventional and synchrotron X-ray diffraction (XRD) analyses mineral species in nanoparticles separated by automated ultrafiltration device (AUD) apparatus.Materials and methods
Soil samples were collected from paleo-environmental lateritic soils. Soil samples were examined using elemental analysis, conventional and synchrotron XRD analyses, high gradient magnetic separation, separation and collection of nanoparticles by AUD apparatus, and transmission electron microscopy (TEM).Results and discussion
The soil pH, redness index, quantities of free Al- and Fe-oxides (Ald and Fed), and clay content of lateritic soils are higher than those of gravel soil layers. Illite, kaolinite, gibbsite, quartz, goethite, and hematite were identified in clay fractions and nanoparticles by conventional and synchrotron XRD analyses. TEM images show presence of hematite nanoparticles on the surface coating of kaolinite nanoparticles and aggregated hematite nanoparticles overlapping the edge of a kaolinite flake in a size range of 4?C7?nm. Synchrotron XRD techniques are more straightforward and powerful than conventional XRD with random powder methods for identifying nanoparticles in red soils, particularly for illite, kaolinite, goethite, and hematite nanoparticles. According to chemical compositions of clay fractions and red soil features in the Taoyuan terrace, these red soils can be taken as lateritic red earths or red earths.Conclusions
This work suggests that physicochemical properties, mineral species, and micromorphology of red soil at all depths can shed light on the extent of paleo-environmental lateritic weathering. 相似文献10.
A role for a 70-kilodalton heat shock protein in lysosomal degradation of intracellular proteins 总被引:44,自引:0,他引:44
A 73-kilodalton (kD) intracellular protein was found to bind to peptide regions that target intracellular proteins for lysosomal degradation in response to serum withdrawal. This protein cross-reacted with a monoclonal antibody raised to a member of the 70-kD heat shock protein (hsp70) family, and sequences of two internal peptides of the 73-kD protein confirm that it is a member of this family. In response to serum withdrawal, the intracellular concentration of the 73-kD protein increased severalfold. In the presence of adenosine 5'-triphosphate (ATP) and MgCl2, the 73-kD protein enhanced protein degradation in two different cell-free assays for lysosomal proteolysis. 相似文献