紫红薯糖蛋白体外抗氧化活性研究

研究紫红薯糖蛋白的体外抗氧化活性。使用水提醇沉方法、Sevage法除游离蛋白,用DEAE-52纤维素层析及SephadexG-75纯化制备糖蛋白。采用超氧阴离子自由基(O-2.)、羟基自由基(·OH)、1,1-二苯基-2-苯肼自由基(DPPH.)清除率测定法及还原力测定法评价紫红薯糖蛋白体外抗氧化活性。糖蛋白在0～640μg/mL内,均具有明显的抗氧化活性,随着质量浓度的增加活性增强;其中在紫红薯糖蛋白的质量浓度为640μg/mL时,对超氧阴离子自由基(O-2.)清除作用达到69.80%;对羟基自由基(.OH)的清除作用达到73.29%。     

Ion Exchanging-Spectrophotometric Determination of Micro Amounts Gallium with Butylrhodamine B in Lead-Zinc Mineral I

This paper developed a spectrophotometric determination of micro amounts of Gallium with butylrhodamineB in lead-zinc mineral. Large amounts of interfering ions Zn 2+ ?Pb 2+ ?Al 3+ ?Ca 2+ can be separated by anion exchange resin. High bond ions can be eliminated by using 6 mol/L hydrochloric acid-ascorbic acid.Gallium remained in column can be eluted by 0.5 mol/L hydrochloric acid. In the presence of acidic and Titanium chloride, by means of benzene extracting,determined the ultraviolet-red complex combined GaCl - 4 with butylrhodamineB.The method has been applied to determination of micro amounts of Gallium in lead-zinc mineral satisfactorily.     

菜籽多酚和Vc在化学模拟体系中清除超氧阴离子和羟自由基的能力

研究菜籽多酚、Vc、菜籽多酚与Vc混合物在化学模拟体系中清除超氧阴离子自由基OH.O2.与羟自由基.OH自由基的能力。用邻苯三酚自氧化法测定抗氧化剂清除OH.O2.的能力,用铁氧化邻二氮菲-Fe2+法测定抗氧化剂清除.OH的能力。结果表明:菜籽多酚、Vc、菜籽多酚与Vc的混合物清除OH.O2.、.OH都不呈剂量-效应关系。菜籽多酚在0.25mg/ml浓度时对OH.O2.与.OH的清除率均最高,分别达51.40%和84.82%。Vc在0.80mg/ml时对OH.O2.的清除率最高,达80.39%;在0.40mg/ml时对.OH的清除率最高,达91.35%。当总浓度为0.25mg/ml时,菜籽多酚与Vc的混合物没有协同增加清除OH.O2.的作用;菜籽多酚与Vc按7∶3、8∶2两种比例混合,在清除.OH时有协同增效作用,协同增效的最佳比例为7∶3,最大清除率达78.78%。     

植物体中的阴离子通道

阴离子通道在调节植物生长发育,营养吸收及适应干旱、盐胁迫、铝毒和缺磷胁迫等不良环境中起重要作用。本文总结介绍了它们在植物体内的广泛定位,细胞功能,基本性质和介入的可能的信号传导过程,使研究者更加深刻地认识植物体中的阴离子通道,以便对各种类型阴离子通道的进一步研究。另外,本文还介绍了保卫细胞膜上S-型阴离子通道的可能蛋白质组成和小麦根尖编码铝诱导苹果酸分泌转运体的可能基因,旨在探讨阴离子通道分子生物学基础的研究方法。     

Exudation of organic anions by roots of cabbage,carrot, and potato as influenced by environmental factors and plant age

A previous study demonstrated that cabbage was P efficient compared to carrot and potato. However, calculating plant P uptake by a mechanistic simulation model based on P transport by diffusion and mass flow, P uptake of roots according to the Michaelis‐Menten kinetics, and morphological root characteristics including root hairs, revealed that these parameters could explain only 2/5 of the total P uptake of cabbage, but 4/5 of that of carrot and potato (Dechassa et al., 2003). Therefore, it was hypothesized that a higher root exudation of organic anions may enhance P mobilization and hence P uptake of cabbage. The objective of this research was to determine root exudation of organic anions by the three species, and to investigate the influence of plant age and dark/light period on organic‐anion exudation by cabbage. Experiments were conducted in a growth chamber in nutrient solution with or without P. Organic anions were determined in root exudates and in root tissue. With cabbage and potato, P deficiency induced exudation of citrate and succinate, respectively. Citrate‐exudation rate of P‐deficient cabbage plants was correlated with accumulation of citrate in root tissue. In contrast, high succinate‐exudation rates in potato were not correlated with an increased concentration in root tissue. For carrot, no change was observed in the exudation of any of the organic anions in response to P deficiency. The results also showed that succinate‐ and citrate‐exudation rates of cabbage roots increased with increased plant age. There was also a significant increase in exudation rates of organic anions of cabbage roots during the light period of the day. It was concluded that cabbage had the ability to exude large amounts of citrate in response to P deficiency by which it can additionally enhance its P‐uptake efficiency, whereas carrot and potato showed little evidence of possessing such a mechanism.     

盐酸制备新型阴离子添加剂产品最佳工艺的研究

本试验根据正交试验L9(34)设计，使用常用蛋白饲料作为载体，盐酸为阴离子源，以最终阴阳离子差（DCAD）值为主要评价指标，同时考虑粗蛋白质含量变化情况，优选新型阴离子添加剂的制备工艺。试验结果表明：在实际生产条件下，以DDGS作为载体，盐酸与水的混合比例为1∶1，采用自然干燥的方法，酸液与载体混合比例为1∶1.5，成品为颗粒状，无不良气味，DCAD值为-2313.69 meq/kg DM，粗蛋白质含量27.28%。     

检测乳管细胞中黄色体产生O_2~-速率的研究

采用羟胺氧化法对橡胶树胶乳中黄色体产生Ｏ２－的速率进行研究，结果表明反应体系 中需加入一定浓度的Ｃａ２＋，并且也要控制适宜的温度与ｐＨ值。研究结果还表明，部分死皮 树胶乳中黄色体产生Ｏ２－的速度大于正常树。     

NO诱导IAA和O2.-积累于侧根尖端促进水稻侧根生长

为了探讨NO和超氧阴离子对水稻种子根侧根生长的影响,以DR5-GUS标记IAA的转基因水稻为材料,种子催芽萌发后,用含有不同浓度的NO供体、NO合成酶抑制剂和清除剂溶液来培养萌发3 d的水稻幼苗,在培养的第3 d和第5 d分别测量初生根长度和初生根上侧根数量,并通过DAF-2DA对NO、GUS对IAA和NBT对超氧阴离子（O₂·^-）染色后,在显微镜下观察NO、IAA和O₂·^-在侧根的定位,分析与NO合成相关的基因表达。结果表明,NO和IAA主要分布在根中柱的维管束部分以及侧根起始形成处和侧根根尖,O₂·^-只极性分布在侧根起始部位和侧根根尖。当NO合成受到抑制或清除时,NO、IAA和O₂·^-在侧根的积累量明显减少,侧根数量及初生根长度也均显著下降。荧光定量PCR分析发现,外源的NO供体SNP处理均能显著诱导水稻OsNIA1和OsNIA2基因表达,而NO合成酶抑制剂处理则抑制OsNIA1和OsNIA2基因表达。基于我...     

儿茶素抗氧化作用的协同增效效应

用电子自旋共振(ESR)和化学发光技术,研究了(-)-EGCG、(-)-ECG、(-)-EC、(-)-EGC 4种儿茶素及其不同组合,对超氧阴离子自由基(O(?))的清除作用。结果表明,单一儿茶素以(-)-EGCG 的清除能力最强,其纳摩尔清除率为316.3,其次为(-)-ECG,纳摩尔清除率为262.9;两两不同组合对O(?)的清除率以(-)-EGCG+(-)-ECG 效果最佳,比各自单独存在时要增效,三三组合时以(-)-EGCG+(-)-ECG+(-)-EC 组合效果最佳,增效效果明显,且强于两两组合。这些组合的增效效果与体系中存在的儿茶素的摩尔浓度呈高度的线性正相关。4种儿茶素组成不同的比例,以茶叶天然组成增效效果最明显。用伏安法测得的各儿茶素第一还原电位由高到低的次序为:(-)-EGCG>(-)-ECG>(-)-EGC≈(-)-EC,这一电位次序是儿茶素构成抗氧化循环的根本所在。     

负离子对动物机体的代谢效应

本文主要介绍了负离子对动物机体代谢影响的机理．负离子能够促进机体的生物氧化增强能量代谢与体内糖、脂肪及蛋白质的合成代谢。