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1.
Antioxidant activities of the 95% ethanol extract from Caesalpinia sappan heartwood (ECS),pro-tosappanin A,protosappanin B,and brazilein were studied in vitro.The inhibition of the formation of malondialdehyde (MDA) and the scavenging of superoxide anions,hydrogen peroxide,and hydroxyl radicals were assayed.The experimental results show that all four substances had antioxidant activity in vitro but their capabilities differed for the different indicators.ECS,protosappanin A,and protosappanin B show more inhi-bition of MDA and scavenging of hydrogen peroxide,while brazilein shows more scavenging of hydroxyl radicals.All the samples show little scavenging of superoxide anions. 相似文献
2.
玉米蛋白生物活性肽的开发 总被引:17,自引:0,他引:17
金英姿 《新疆师范大学学报(自然科学版)》2004,23(2):40-42
玉米蛋白含有丰富的蛋白质和独特的氨基酸组成,通过酶法改性可得到大量的生物活性肽。本介绍了玉米蛋白酶解物中的生物活性肽及其特殊的生理功能,利用低价值的玉米蛋白生产高附加值的生物活性肽具有原料来源丰富、成本低、安全性好等特点,可以充分利用玉米资源,大大提高玉米加工企业的经济效益和社会效益,应用前景十分广阔。 相似文献
3.
X. Wang C. A. Lessman D. B. Taylor T. K. Gartner 《Cellular and molecular life sciences : CMLS》1995,51(11):1097-1102
Gastrulation is characterized by dramatic cell migration which is thought to require the interaction of cell adhesion molecules with extracellular molecules. We have tested two novel peptides, a fibronectin peptide and a fibronectin receptor peptide, for their effects on gastrulation of the leopard frogRana pipiens. The fibronectin peptide DRVPHSRNSIT corresponds to residues 1373–1383 of the cell-binding domain of fibronectin; the receptor peptide DLYYLMDL corresponds to residues 124–131 of 1 subunit of a variety of integrins including 51. Either of these peptides significantly inhibited gastrulation after being microinjected into mid-blastulae. These results indicate that these sequences may correspond to the ligand/receptor interaction sites of fibronectin and its receptor(s). 相似文献
4.
冷明伟 《渤海大学学报(自然科学版)》2008,29(3)
针对T205原生产工艺中存在的产品过滤难、原料消耗高、收率低、成本高等突出问题,通过优化原料配比和采用促进剂等措施,优化了T205合成工艺,使产品易过滤、收率高、成本低,经济效益大幅度提高。 相似文献
5.
为探究红树林幼苗对全日潮淹水-盐度交互处理的适应机制,本研究通过在室内模拟北部湾全日潮潮汐规律,测定不同淹水-盐度交互处理条件下蜡烛果(Aegiceras corniculatum)、海榄雌(Avicennia marina)、木榄(Bruguiera gymnorhiza)、秋茄(Kandelia obovata)和红海兰(Rhizophora stylosa) 5种红树林幼苗的过氧化氢酶(CAT)活性、超氧化物歧化酶(SOD)活性和过氧化物酶(POD)活性,并对其变化特征进行分析。结果表明:(1)当淹水时间不变时,随着盐度的增加,蜡烛果的CAT活性呈上升趋势、SOD活性呈下降趋势;除淹水时间为4 h外,海榄雌的POD活性呈上升趋势。(2)当盐度不变时,随着淹水时间的增加,蜡烛果的CAT活性和海榄雌的POD活性总体呈下降趋势;除盐度为5外,蜡烛果的SOD活性呈上升趋势,海榄雌的CAT活性呈先下降后上升的趋势。(3)不同淹水-盐度交互处理下,蜡烛果的CAT、SOD、POD活性随着时间的推移总体呈先上升后下降的趋势;海榄雌、木榄、秋茄和红海兰的CAT活性总体均呈下降趋势,SOD活性总体均呈先上升后下降的趋势;海榄雌的POD活性呈先上升后下降再上升的趋势,而木榄、秋茄和红海兰的POD活性变化不大。(4)淹水-盐度交互处理对海榄雌的POD活性以及对蜡烛果的CAT活性和SOD活性影响较大,而对木榄、秋茄和红海兰影响较小。不同树种对淹水-盐度交互处理的生理响应不同,在红树林实际造林时应根据各红树林树种对盐度和潮位高低的生理适应特征来选择合适的树种。 相似文献
6.
研究了蓝莓提取物的种类、提取纯化方法以及蓝莓在食品、保健等方面的应用.结果表明,蓝莓富含花青素、黄酮、多酚和多糖等抗氧化物质,在食品和营养保健等领域有着广泛的应用潜力,是一种营养价值和经济价值极高,发展潜力巨大的果树. 相似文献
7.
《自然科学进展(英文版)》2020,30(5):686-696
The patterning of neuronal cells and guiding neurite growth are important for neuron tissue engineering and cell-based biosensors. In this paper, inkjet printing has been employed to pattern self-assembled I3QGK peptide nanofibers on silk substrates for guiding the growth of neuron-like PC12 cells. Atomic force microscopy (AFM) confirmed the dynamic self-assembly of I3QGK into nanofiber structures. The printed self-assembled peptide strongly adheres to regenerated silk fibroin (RSF) substrates through charge-charge interactions. It was observed that in the absence of I3QGK, PC12 cells exhibited poor attachment to RSF films, while for RSF surfaces coated or printed with peptide nanofibers, cellular attachment was significantly improved in terms of both cell density and morphology. AFM results revealed that peptide nanofibers can promote the generation of axons and terminal buttons of PC12 cells, indicating that I3QGK nanofibers not only promote cellular attachment but also facilitate differentiation into neuronal phenotypes. Inkjet printing allows complex patterning of peptide nanofibers onto RSF substrates, which enabled us to engineer cell alignment and provide an opportunity to direct axonal development in vitro. The live/dead assay showed that printed I3QGK patterns exhibit no cytotoxicity to PC12 cells demonstrating potential for future nerve tissue engineering applications. 相似文献
8.
测定了食用菌的含水量(w水)、高分子活性中心元素含量以及羟自由基清除能力,计算了食用菌中高分子活性中心元素(Ti、V、Cr、Mn、Mo、Zn、Fe、Co、Ni、Cu和Sr)的分布。结果表明,由含水量校正过的高分子活性中心元素分布参数(1-w水)1/3ln(k2r1/r2)与羟自由基清除能力参数ln[F(1-w水)3]之间有很好的线性关系。由此笔者认为可以把此高分子活性中心元素分布参数作为近似判断抗氧化能力大小的依据之一,通过此参数可评价食用菌的抗氧化性。 相似文献
9.
Gold nanoshells (GNSs), consisting of a dielectric core coated with gold, have gained extensive attention as they show readily tunable optical properties and good biocompatibility. As highly sensitive and label-free optical biosensors with wide applications, GNSs have been investigated in many fields including drug delivery, immunoassay, cancer treatment, biological sensing and imaging. Taking advantage of the adjustability of the local surface plasmon resonance (LSPR) and the sensitivity of the surfaceenhanced Raman scattering (SERS) signal of GNSs, we have developed diverse applications including plasmonic biosensors and nanoprobes based on GNSs. In this review we introduce plasmonic and electromagnetic properties and fabrication methods of GNSs. We describe research progress in recent years, and highlight several applications of GNSs developed by our group. Finally we provide a brief assessment of future development of GNSs as plasmonic materials that can be integrated with complementary analytical techniques. 相似文献
10.
A surface plasmon resonance (SPR) technique was developed as an online screening method to identify effective adsorbents for the peptide NH2-Cys-Thr-Trp-Trp-COOH (CW-4). To validate the SPR technique, several linear polymers containing amino acid residues were synthesized as models of their corresponding adsorbents. SPR screening of all the linear polymers demonstrated that the linear polymer containing phenylalanine residues (PPhe) exhibited the highest affinity for CW-4 among the polymers tested. In accordance with the screening results from SPR, the adsorbent containing phenylalanine (APhe) exhibited the highest adsorption capacity for CW-4. An interesting observation was that the amounts of CW-4 adsorbed on 3 adsorbents were quite small, even though both SPR and isothermal titration calorimetry (ITC) experiments indicated the presence of interactions between CW-4 and the three polymers. A kinetic analysis performed using SPR technology suggested such a phenomenon was ascribed to the poor stability of the CW-4/polymer complexes; that is, CW-4 associates with the polymers quickly, but it also dissociated quickly. The combined results suggested that SPR was a promising tool to identify the optimal adsorbent for peptides, analyze the interactions contributing to adsorption and explain adsorption phenomena using polymer models. 相似文献