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按照Taylor法(还原剂为NaBD4)将从枸杞子中分离出来的阿拉伯半乳糖聚糖糖蛋白Cp-2-B中含有的半乳糖醛酸还原成重氢标记的半乳糖,对还原前后的样品进行甲基化处理后供GC-MS。 结果发现Cp-2-B分子中存在着非还原末端,(1→3)- 结合以及(1→4)- 结合等3种半乳糖醛酸残基。核磁共振分析也证实了这一结论。另外,从Cp-2-B与果胶粗酶以及果胶内切酶的反应结果可以推测出,半乳糖醛酸残基以分散状态或者短链形式存在,分子中不存在类似果胶物质那样的、由连续的(1→4)结合的半乳糖醛酸组成的Smooth领域。 相似文献
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藤茶多糖的抗氧化作用研究 总被引:20,自引:5,他引:20
目的: 探讨藤茶多糖的体内外抗氧化作用。 方法: (1)测定藤茶多糖(Ampelopsis Grossedentata polysaccharide,AGP)的还原能力;(2)测定AGP在化学模拟体系、体外血清的抗活性氧能力;(3)测定AGP对小鼠肝匀浆、小鼠肝线粒体MDA生成的影响;(4)用分光光度法测定H2O2诱导小鼠红细胞溶血和Fe2+-VC诱导的肝线粒体肿胀程度来研究AGP的抗氧化效果;(5)小鼠随机分成对照与AGP组,腹腔注射AGP 150mg/kg•bw•d 12d后,测定小鼠血清抗活性氧能力及肝组织MDA含量。 结果: AGP具有一定的还原能力,一定浓度范围内具有显著的体外抗活性氧能力并能抑制小鼠肝组织及肝线粒体MDA的生成,可减少红细胞诱导溶血和肝线粒体肿胀程度,对小鼠体内肝组织MDA生成的抑制作用显著。 结论: AGP一定浓度范围内具有抗氧化作用。 相似文献
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Huiting Huang Yingjing Miao Yuting Zhang Li Huang Jiashu Cao Sue Lin 《International journal of molecular sciences》2021,22(23)
Arabinogalactan proteins (AGPs) are a superfamily of hydroxyproline-rich glycoproteins that are massively glycosylated, widely implicated in plant growth and development. No comprehensive analysis of the AGP gene family has been performed in Chinese cabbage (Brassica rapa ssp. chinensis). Here, we identified a total of 293 putative AGP-encoding genes in B. rapa, including 25 classical AGPs, three lysine-rich AGPs, 30 AG-peptides, 36 fasciclin-like AGPs (FLAs), 59 phytocyanin-like AGPs, 33 xylogen-like AGPs, 102 other chimeric AGPs, two non-classical AGPs and three AGP/extensin hybrids. Their protein structures, phylogenetic relationships, chromosomal location and gene duplication status were comprehensively analyzed. Based on RNA sequencing data, we found that 73 AGP genes were differentially expressed in the floral buds of the sterile and fertile plants at least at one developmental stage in B. rapa, suggesting a potential role of AGPs in male reproductive development. We further characterized BrFLA2, BrFLA28 and BrFLA32, three FLA members especially expressed in anthers, pollen grains and pollen tubes. BrFLA2, BrFLA28 and BrFLA32 are indispensable for the proper timing of pollen germination under high relative humidity. Our study greatly extends the repertoire of AGPs in B. rapa and reveals a role for three members of the FLA subfamily in pollen germination. 相似文献
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对相对论性的 AGP 方程进行了求解.得出了在引力场中,超流液 He 作孤立于运动的特征.并对在超流体中观察到的宏观量子效应进行了解释. 相似文献
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文中介绍了如何使用DirectX实现采样数据的图形实时显示,介绍了DirectDraw的结构和实现过程。并且介绍了一个使用DirectX实现的人体信号的图形实时显示。 相似文献
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章深入浅出地介绍了现行PC系统中图形子系统的主流技术规范AGP的相关概念及知识,旨在帮助普通PC用户对AGP有一个初步认识. 相似文献
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Marangon M Van Sluyter SC Robinson EM Muhlack RA Holt HE Haynes PA Godden PW Smith PA Waters EJ 《Food chemistry》2012,135(3):1157-1165
Bentonite is commonly used to remove grape proteins responsible for haze formation in white wines. Proteases potentially represent an alternative to bentonite, but so far none has shown satisfactory activity under winemaking conditions. A promising candidate is AGP, a mixture of Aspergillopepsins I and II.; a food grade, well characterized and inexpensive protease, active at wine pH and at high temperatures (60-80°C). AGP was added to two clarified grape juices with and without heat treatments (75°C, 1min) prior to fermentation. AGP showed some activity at fermentation temperatures (≈20% total protein reduction compared to control wine) and excellent activity when combined with juice heating (≈90% total protein reduction). The more heat stable grape proteins, i.e. those not contributing to wine hazing, were not affected by the treatments and therefore accounted for the remaining 10% of protein still in solution after the treatments. The main physicochemical parameters and sensorial characteristics of wines produced with AGP were not different from controls. 相似文献
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《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2013,30(9):1413-1424
Mass spectrometric methods were developed and validated for the analysis in chicken muscle of a range of antibiotic growth promoters: spiramycin, tylosin, virginiamycin and bacitracin, and separately for two marker metabolites of carbadox (quinoxaline-2-carboxylic acid and 1,4-bisdesoxycarbadox), and a marker metabolite of olaquindox (3-methyl-quinoxaline-2-carboxylic acid). The use of these compounds as antibiotic growth promoters has been banned by the European Commission. This study aimed to develop methods to detect their residues in muscle samples as a means of checking for the use of these drugs during the rearing of broiler chickens. When fed growth-promoting doses for 6 days, spiramycin (31.4?µg?kg?1), tylosin (1.0?µg?kg?1), QCA (6.5?µg?kg?1), DCBX (71.2?µg?kg?1) and MQCA (0.2?µg?kg?1) could be detected in the muscle 0 days after the withdrawal of fortified feed. Only spiramycin could consistently be detected beyond a withdrawal period of 1?day. All analytes showed stability to a commercial cooking process, therefore raw or cooked muscle could be used for monitoring purposes. 相似文献