Lobocrassins A-E: new cembrane-type diterpenoids from the soft coral Lobophytum crassum     

Kao CY  Su JH  Lu MC  Hwang TL  Wang WH  Chen JJ  Sheu JH  Kuo YH  Weng CF  Fang LS  Wen ZH  Sung PJ 《Marine drugs》2011,9(8):1319-1331

Five new cembrane-type diterpenoids, lobocrassins A-E (1-5), were isolated from the soft coral Lobophytum crassum. The structures of cembranes 1-5 were established by spectroscopic and chemical methods and by comparison of the spectral data with those of known cembrane analogues. Lobocrassin A (1) is the first cembranoid possessing an α-chloromethyl-α-hydroxy-γ-lactone functionality and is the first chlorinated cembranoid from soft corals belonging to the genus Lobophytum. Lobocrassins B (2) and C (3) were found to be the stereoisomers of the known cembranes, 14-deoxycrassin (6) and pseudoplexaurol (7), respectively. Lobocrassin B (2) exhibited modest cytotoxicity toward K562, CCRF-CEM, Molt4, and HepG2 tumor cells and displayed significant inhibitory effects on the generation of superoxide anion and the release of elastase by human neutrophils.  相似文献   

Bioactive cembranoids from the dongsha atoll soft coral Sarcophyton crassocaule     

Lin WY  Lu Y  Su JH  Wen ZH  Dai CF  Kuo YH  Sheu JH 《Marine drugs》2011,9(6):994-1006

Seven new cembranoids, sarcocrassocolides F-L (1-7), have been isolated from a soft coral Sarcophyton crassocaule. Their structures were determined by extensive spectroscopic analysis. Most new compounds exhibited significant cytotoxic activity against a limited panel of cancer cell lines, and the structure-activity relationship was studied. Compounds 1-7 were found to display significant in vitro anti-inflammatory activity in LPS-stimulated RAW264.7 macrophage cells by inhibiting the expression of the iNOS protein. Compound 4 was also found to effectively reduce the level of COX-2 protein.  相似文献   

Natural product chemistry of gorgonian corals of genus Junceella--part II     

Wu YC  Su JH  Chou TT  Cheng YP  Weng CF  Lee CH  Fang LS  Wang WH  Li JJ  Lu MC  Kuo J  Sheu JH  Sung PJ 《Marine drugs》2011,9(12):2773-2792

The structures, names, bioactivities, and references of 81 new secondary metabolites obtained from gorgonian corals belonging to the genus Junceella are described in this review. All compounds mentioned in this review were obtained from sea whip gorgonian corals Junceella fragilis and Junceella juncea, collected from the tropical and subtropical Indo-Pacific Ocean.  相似文献   

Optimization of the needle punching process for the nonwoven fabrics with multiple quality characteristics by grey-based taguchi method     

Chung-Feng Jeffrey Kuo  Te-Li Su  Cheng-Ping Tsai 《Fibers and Polymers》2007,8(6):654-664

This study is intended for finding out the optimal processing parameters for needle punching nonwoven fabrics in order to work out its maximal strength. Taguchi method together with grey relational analysis is employed to resolve the problem as regards multiple-quality optimization, and further discover the optimal combination of processing parameters for needle punching nonwoven fabrics. Firstly, orthogonal array L₁₈(2¹×3⁷) is used to deal with the processing parameters that may exert influence over the manufacturing of needle punching nonwoven fabrics. Then grey relational analysis is applied to resolve the deficiency of Taguchi method that focus on single quality characteristic. Next, the response table of grey relational analysis is used to obtain the optimal combination of processing parameters for multiple quality characteristics. In the current experiment quality characteristic refers to the tensile strength and tear strength of the nonwoven fabrics. Additionally, signal-to-noise ratio (SN ratio) calculation and analysis of variance (ANOVA) can be adopted to explore the experimental results. Through ANOVA, the significant factors that exert comparatively significant influence over the quality characteristic of the needle punching nonwoven fabrics, that is, the control factors are determined so that the quality characteristic of the needle punching nonwoven fabrics can be effectively controlled. Finally, confirmation experiment is conducted within 95 % confidence interval to verify the experimental reliability and reproducibility.  相似文献   

舀种勺式半精量点种器的工作原理与整体结构设计     

田括  陈永成  陈镜洪  代亚猛  翟超 《农机化研究》2013,35(5):115-118

建立了舀种勺式半精量点种器的结构示意图,分析了其工作原理,并对点种器结构和主要参数进行了确定.同时,分析了该种点种器正常工作状态下,排种勺的取种、投种等工作过程,建立其动力学模型,得出了舀种勺式半精量点种器的种子室、圆盘、取种勺的最优化设计.根据田间试验的数据分析表明,点种器正常工作时,内盘旋转的角速度范围是0.58 ～0.81r/s.  相似文献   

6-shogaol (alkanone from ginger) induces apoptotic cell death of human hepatoma p53 mutant Mahlavu subline via an oxidative stress-mediated caspase-dependent mechanism     

Chen CY  Liu TZ  Liu YW  Tseng WC  Liu RH  Lu FJ  Lin YS  Kuo SH  Chen CH 《Journal of agricultural and food chemistry》2007,55(3):948-954

Mahlavu cells, poorly differentiated and p53 mutants of a human hepatoma subline, are known to be highly refractory to a number of chemotherapeutic agents and radiotherapy due to their high expressions of multidrug resistance gene-1 (MDR-1) and Bcl-2 proteins. Thus, it is desirable to search for an alternative strategy for effective eradication of this type of cancer cells. We present evidence here for the first time that 6-shogaol (6-SG), an alkanone isolated from the rhizomes of ginger, can effectively induce apoptotic cell death of Mahlavu cells via an oxidative stress-mediated caspase-dependent mechanism. The cascade of events in 6-SG-induced apoptosis of these cells involved an initial overproduction of reactive oxygen species (ROS) followed by a severe depletion of intracellular glutathione (GSH) contents. Both events consequently entailed a significant drop in mitochondrial transmembrane potential (DeltaPsim), which ultimately activated the activities of caspases 3/7 resulting in the DNA fragmentation. Interestingly, we also found that N-acetylcysteine (NAC), an antioxidant and a precursor of GSH biosynthesis, could offer a near complete protection of apoptotic cell death exerted by 6-SG. Similarly, exogenously added GSH could also provide protection with an equal efficacy. However, it was paradoxical that both Boc-Asp(OMe)-fmk (a broad caspases inhibitor) and cyclosporin A (an mitochondrial permeability transition opening inhibitor) could only partially protect these cells from 6-SG-induced apoptosis. Taking these data into consideration, it is obvious that GSH depletion is the major contributing factor in arbitrating 6-SG-induced apoptosis of Mahlavu cells. In conclusion, we provide here a novel modality that can help to eradicate a p53 mutant of human hepatoma cells by using a natural consistent isolated form of ginger. These data also provide evidence to reaffirm the notion that consumption of certain foodstuffs can be beneficial to health because some of the constituents contained in them may be anticarcinogenic.  相似文献   

Different central manifestations in response to electroacupuncture at analgesic and nonanalgesic acupoints in rats: a manganese-enhanced functional magnetic resonance imaging study   总被引：6，自引：0，他引：6       下载免费PDF全文

Jen-Hwey Chiu  Mao-Shu Chung  Hui-Cheng Cheng  Tzu-Cheng Yeh  Jen-Chuen Hsieh  Chung-Yen Chang  Wan-Yo Kuo  Henrich Cheng    Low-Tone Ho 《Canadian journal of veterinary research》2003,67(2):94-101

Acupuncture analgesia is an important issue in veterinary medicine. This study was designed to elucidate central modulation effects in response to electroacupuncture (EA) at different acupoints. Manganese-enhanced functional magnetic resonance imaging was performed in Sprague-Dawley rats after sham acupuncture, sham EA, or true EA at somatic acupoints. The acupoints were divided into 3 groups: group 1, analgesic acupoints commonly used for pain relief, such as Hegu (LI 4); group 2, nonanalgesic acupoints rarely used for analgesic effect, such as Neiguan (PC 6); and group 3, acupoints occasionally used for analgesia, such as Zusanli (ST 36). Image acquisition was performed on a 1.5-T superconductive clinical scanner with a circular polarized extremity coil. The results showed that there was no neural activation caused by EA at a true acupoint with shallow needling and no electric current (sham acupuncture). When EA at a true acupoint was applied with true needling but no electric current (sham EA), there was only a slight increase in brain activity at the hypothalamus; when EA was applied at a true acupoint with true needling and an electric current (true EA), the primary response at the hypothalamus was enhanced. Also, there was a tendency for the early activation of pain-modulation areas to be prominent after EA at analgesic acupoints as compared with nonanalgesic acupoints. In conclusion, understanding the linkage between peripheral acupoint stimulation and central neural pathways provides not only an evidence-based approach for veterinary acupuncture but also a useful guide for clinical applications of acupuncture.  相似文献   

Effect of docosahexaenoic acid and arachidonic acid on the expression of adipocyte determination and differentiation-dependent factor 1 in differentiating porcine adipocytes     

Liu BH  Kuo CF  Wang YC  Ding ST 《Journal of animal science》2005,83(7):1516-1525

  相似文献   

佛甲草中SOD提取条件的优化   总被引：3，自引：2，他引：1  

陈莉  申小蓉  赵红洋  刘括 《草原与草坪》2009,(1)

对景天科植物佛甲草超氧化物歧化酶(SOD)的抽提缓冲液pH值,抽提时间,热处理的温度和时间进行正交实验,并对丙酮沉淀法和硫酸铵盐析法初步纯化SOD粗酶液进行了优化和比较。结果表明:抽提缓冲液的pH值为7.8,抽提时间为2 h,热处理温度为50℃,热处理时间为15 min时,得到佛甲草SOD的相对最大提取酶活力;饱和度为90%的硫酸铵盐析是初步纯化佛甲草SOD的最优条件,其纯化倍数为4.10,回收率为0.71,为进一步的层析以制备更纯佛甲草SOD提供了理论的条件。  相似文献   

冻融损伤对再生混凝土耐久性及与钢筋粘结性能分析     

王晨霞  钤建勋  王浩  徐阔  曹芙波 《保鲜与加工》2016,(2):131-139

制作掺入引气剂和未掺入引气剂的100%粗骨料取代率的再生混凝土RC1和RC2两组试件以及掺入引气剂和未掺入引气剂的普通混凝土NC1和NC2两组试件,并分别对经过不同次数冻融循环试件的抗压强度、质量损失率、动弹性模量损失率进行研究。结果表明,冻融后各组试件的抗压强度、质量损失率及动弹性模量损失率均降低,对于添加引气剂的NC1和RC1两组试件损失较小,其中RC1组试件在200次冻融后抗压强度损失接近40%,质量损失率达0.5%,动弹性模量损失率38.5%。100%取代率并加入引气剂的ZRC组试件冻融后进行中心拨出实验,发生劈裂破坏和钢筋拔出破坏2种形式。再生粗骨料混凝土与钢筋的极限粘结应力均随冻融次数的增加而降低,200次冻融后极限粘结应力下降33.5,荷载滑移曲线既有上升段也有下降段。  相似文献