385 resultados para HPLC-ELSD


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A new HPLC-APCI/MS method for the identification of ginsenosides has been developed. The analyses were performed on a reversed-phase C-18 column using a binary eluent (acetonitrile and water) under gradient conditions. Although APCI is a high-temperature evaporative process, HPLC-APCI/MS could effectively identify thermo-labile ginsenosides. The [M-H](-) ions and the thermal degradation ions of ginsenosides could be clearly observed under negative and positive ion conditions, respectively, and these were used to identify the molecular masses, the aglycone structures and the sugar groups of ginsenosides. APCI/MS can provide more explicit information than ESI/MS for identifying and distinguishing ginsenosides. Using the HPLC-APCI/MS method, 35 ginsenosides were identified in Panax ginseng. Copyright (C) 2005 John Wiley & Sons, Ltd.

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Biofingerprinting chromatogram, analysis, which is defined as the comparison of fingerprinting chromatograms of the extract of traditional Chinese medicines (TCMs) before and after the interaction with biological systems (DNA, protein. cell. etc.), was proposed for screening and analysis of the multiple bioactive compounds in TCMs. A method of microdialysis sampling combined with high performance liquid chromatography (HPLC) was applied to the study of DNA-binding property for the extracts of TCMs. Seven compounds were found to bind to calf thymus DNA (ct-DNA) from the TCMs of Coptis chinensis Franch (Coptis), but only three ones from Phellodendron amurense Rupr. (Phellodendron) and none from Sophoraflavescens Ait. (Sophora) to bind to ct-DNA. respectively. Three of them were identified as berberine, palmatine and jatrorrhizine and their association constants (K) to ct-DNA were determined by microdialysis/HPLC. Competitive binding behaviors of them to ct-DNA were also investigated. © 2005 Elsevier B.V. All rights reserved.

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Performance of comprehensive two-dimensional liquid chromatography system is greatly improved than we reported previously by using a silica monolithic column as for the second dimensional separation. Due to the increase of the elution speed on the second dimensional monolithic column, the first dimensional column efficiency and analysis rate can be greatly improved as comparing with conventionally second dimensional column. The developed system was applied to analysis of methanol extraction of two umbelliferae herbs Ligusticum chuanxiong Hort. and Angelica sinensis (Oliv.) Diels by using CN column as for the first dimensional separation and a silica monolithic ODS column for the second dimensional separation, and the obtained three-dimensional chromatograms were treated by normalization of peak heights with the value of the highest peak or setting a certain value using a software written in-house. It was observed that much more peaks for low-abundant components in TCM extract can clearly be detected here than we reported before, due to the large difference for the amount of components in TCMs' extract. With the above improvements in separation performance and data treatment, totally about 120 components in methanol extraction of Rhizoma chuanxiong and 100 in A. sinensis were separated with UV detection within 130 min. This result meant that both the number of peaks detected increase twice but the analysis time decease twice if comparing with the previously reported result. (c) 2005 Published by Elsevier B.V.

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Interaction of traditional Chinese Herb Rhizoma Chuanxiong and protein was studied by microdialysis coupled with high performance liquid chromatography. Compounds in Rhizoma Chuanxiong, such as ferulic acid, senkyunolide A and 3-butylphthalide, were identified by HPLC, HPLC-MS and UV-vis. Microdialysis recoveries and binding degrees of compounds in Rhizoma Chuanxiong with human serum albumin (HSA) and other human plasma protein were determined: recoveries of microdialysis sampling ranged from 36.7 to 98.4% with R.S.D. below 3.1%; while binding to HSA ranged from 0 to 91.5% (0.3 mM HSA) and from 0 to 93.5% (0.6 mM HSA), respectively. Compared with HSA, most of compounds bound to human blood serum more extensively and the results showed that binding of these compounds in Rhizoma Chuanxiong was influenced by pH. Two compounds were found to bind to HSA and human blood serum. their binding degrees were consistent with ferulic acid and 3-butylphthalide, the active compounds in Rhizoma Chuanoxiong. (c) 2005 Elsevier B.V. All rights reserved.

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该项目属农业科学技术学科,主要内容涉及到农产品贮藏、园艺采后生物学、植物学等领域。园艺产品品质是影响和制约其贮运保鲜的关键因素,该项目在园艺产品采后品质研究方面取得了重要进展:本项目首次从多酚氧化酶、花色素苷酶、褐变底物和能量亏损等多方面系统性提出了荔枝果实采后褐变机理;确定了香蕉、芒果、草莓等果实采后新的乙烯受体形成特点和规律以及贮藏环境和外源乙烯的响应特性;从乙烯结合位点、乙烯作用和扩展蛋白、苯丙氨酸解氨酶的基因表达等方面阐明了香蕉果实冷害发生的可能原因,丰富了果实冷害发生的作用机制;系统研究荔枝、龙眼、芒果、桃、甜樱桃、柑桔、冬枣、李、西兰花、康乃馨、月季切花等园艺产品采后的生理代谢特点,揭示了在不同贮藏条件下园艺产品品质的变化规律和调控机制;在技术和方法上,首次提出了果实组织ATP、ADP和AMP含量的快速HPLC测定技术;建立新的乙烯结合位点合成速率的测定技术;提出了以电导率为指标,建立了果实品质的定量评价方法,能更好评价/预测园艺产品的品质。该成果揭示了园艺产品采后品质调控的生理代谢特征和规律性变化,对影响品质的关键性问题(如衰老、褐变、冷害等)进行了深入研究,获得了最新成果,在研究方法上也取得了突破。研究成果在国际核心期刊上发表SCI收录论文72篇,获得国际科学基金Jubilee Award,得到国内外同行专家的关注并被广泛引用(被SCI论文引用323篇次);在荔枝、龙眼等果实采后研究领域处于国际领先地位。

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表型是基因型和环境共同作用的结果,环境对物种进化起到了至关重要的作用。虽然人们已经知道环境因子会影响植物花青素的最终含量,但这样的影响是如何在自然环境中进行的仍是未知。较之以前泛泛研究经济作物或模式植物的花青素总含量与人工环境变量的关系的工作,本文探讨环境变化对半野生的圆叶牵牛自然状态下不同基因型植株、不同花青素的影响。 65株取自全国各地包括3种颜色8种基因型的圆叶牵牛被分别种到了温室和室外,温室32株,室外35株,用高效液相 (HPLC) 的方法检测盛花期 (07年9月-10月) 圆叶牵牛花中花青素的含量,同时每天分早中晚采集3次温室和室外的环境数据-照度、紫外线强度、温度、湿度。记录每朵花着生高度、朝向、当天植株开花数、植株根茎、植株生长天数等个体信息。 通过保留时间、紫外-可见吸收光谱数据、质谱数据以及参考文献确定了圆叶牵牛花瓣中主要的5种花青素,包括三个矢车菊素 (CY) 和两个天竺葵素 (PG),根据它们所含的咖啡酸和葡萄糖基的个数将它们简写成CY3C4G、CY2C4G、CY3C5G、PG2C4G、PG3C5G。CY2C4G和CY3C4G仅在蓝紫色花中大量存在,PG2C4G及PG3C5G仅在粉色花中大量存在,CY3C5G在两种颜色的圆叶牵牛花中均有存在。 温室和室外的四个环境因子有显著差异,平均照度室外为温室的3.06倍,平均紫外线强度为温室的5.39倍。Z 检验表明,蓝紫色花中的CY3C5G在温室内外没有显著差异 (P=0.3070),而温室内的CY2C4G (P<0.0001) 和CY3C4G (P<0.0001) 含量明显的低于室外,粉花中CY3C5G和PG3C5G在温室 (P=0.4533) 和室外 (P=0.9577) 没有显著差异,PG2C4G在温室内含量明显 (P=0.0003) 低于室外。 通过Kruskal- Wallis 检验,不同基因型植株各种花青素的相对含量显著不同 (P<0.0001)。室外不同基因型植株的花青素绝对含量显著不同 (P<0.0001)。温室不同基因型植株中,CY2C4G (P=0.0224) 和CY3C4G (P=0.0017) 的绝对含量显著不同,显著性比室外的低些。CY3C5G不同基因型的绝对含量有差异,但是差异不显著 (P=0.0633)。基因型对植株中各个花青素相对含量的影响是尤其显著的,基因型对于花青素绝对含量的影响,可能是基因型直接作用和不同基因型对环境差异的不同响应两方面造成的,所以在环境变异稍大的条件下,基因型更加能显示出它对花青素的含量的影响。 植株的生长天数与粉色圆叶牵牛的PG2C4G、PG3C5G以及蓝紫色圆叶牵牛的三个花青素呈一定的正相关,当天开花数对粉色花的PG3C5G以及蓝紫色花的三个花青素呈负相关,花的朝向 (北-东-南-西-北 对应数值为0-90-180-90-0),对粉花的PG2C4G以及蓝紫花的CY2C4G和CY3C4G 呈正相关,植株大小对粉花的PG2C4G、PG3C5G以及蓝紫花的CY3C5G呈负相关。花所着生的高度对两种颜色花的影响是不同的,与蓝紫花的三个花色素呈负相关,对于粉色的PG2C4G、CY3C5G呈正相关。

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从七叶树(Aesculus Chinensis Bunge)的未成熟的果实的子叶中诱导出愈伤组织;愈伤组织在pH5.8,温度26 ± 1 ℃,加有NAA,TBA,K,CA的MS培养基上生长良好。光对愈伤组织的生长有促进作用,植醇对生长有抑制作用;进行了发酵罐培养。 利用TLC、质谱分离鉴定了γ-生育酚的存在,并利用HPLC、荧光法测定了生育酚的含量。结果表明,愈伤组织中生育酚的含量在3.2~6.6mg/100g干重;光对生育酚的合成有促进作用;植醇是生育酚合成的可能前体;悬浮培养不利于生育酚的合成,培养液中没有发现生育酚的存在。生育酚的合成与组织的生长速率成正相关。

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诱导风信子(Hyacnthus orientalis L.)同一花被外植体上不同部位细胞分化花芽,从外源激素的作用和内探激素的变化探讨细胞脱分化启动的原因,研究了不同外源激素的组合下同一花被不同部位花芽分化的诱导频率:测定了花被上、中,下三部位切块离体培养前后的内源IAA和Z+ZR的含量;在此之前研究了GC-MS.MIM内标法测定微量植物材料内源IAA含量的可行性. GC-MS.MIM内标法是测定微量(0.5-1g)植物材料内源IAA含量的一种比较理想的方法,所需材料量一般为0.58.这一方法的材料前处理采用粗提液用C18Sep-pak柱初步分离纯化.HPLC进一步纯化,能获得纯度高的样品,且操作简便,省时省力. 风信子同一花被不同部位细胞均能分化花芽.当培养基中附加2.0mg/l Zeatin或2.0mg/16-BAP时,随着外探IAA浓度从0升高到10.0mg/l.捆胞分化花芽的部位从花被下部向上部移动。 离体培养前后同一花被上、中、下三部位内源IAA和Z+ZR含量测定结果表明.风信子同一花被内源IAA含量是上部最高,下部次之,中部最低,而内源Z+ZR含量从上向下依次增加;在附加不同外源激素的MS培养基上培养3天后,同一花被上,中、下三部位内源IAA和Z+ZR含量部有一定的变化。