317 resultados para HPLC-DAD-MS
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A simple and sensitive high-performance liquid chromatographic (HPLC) method with fluorescence detection and mass spectrometric identification has been developed for analysis of 30 long-chain and short-chain free Fatty acids (FFAs). The fatty acids were derivatized to their esters with 1-[2-(p-toluenesulfonate)ethyl]-2-phenylimidazole-[4,5-f]-9,10-phenanthrene (TSPP) in N,N-dimethylformamide (DMF) at 90 degrees C with anhydrous K2CO3 as catalyst. A mixture Of C-1-C-30 fatty acids was completely separated within 60 min by gradient elution on a reversed-phase C-8 column. Qualitative identification of the acids was performed by atmospheric-pressure chemical ionization mass spectrometry (APCI-MS) in positive-ion mode. The fluorescence excitation and emission wavelengths were 260 and 380 nm, respectively. Quantitative determination of the 30 acids in two Tibetan medicines Gentiana straminea and G. dahurica was performed. The results indicated that the medicines contained many FFAs. Linear correlation coefficients for the FFA derivatives were > 0.9991. Relative standard deviations (RSDs, n = 6) for the fatty acid derivatives were < 3%. Detection limits (at a signal-to-noise ratio of 3:1) were 3.1-38 fmol. When the fatty acid derivatives were determined in the two real samples results were satisfactory and the sensitivity and reproducibility of the method were good.
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A sensitive method for the determination of free fatty acids using 2-(2-(anthracen-10-yl)-1H-naphtho[2,3-dimidazol-1-yl) ethyl-p-toluenesuIfonate (ANITS) as tagging reagent with fluorescence detection has been developed. ANITS could easily and quickly label fatty acids in the presence of the K2CO3 catalyst at 90 degrees C for 40 min in N,N-dimethylformamide solvent. From the extracts of rape bee pollen samples, 20 free fatty acids were sensitively determined. Fatty acid derivatives were separated on a reversed-phase Eclipse XDB-C8 column by HPLC in conjunction with gradient elution. The corresponding derivatives were identified by post-column APCI/MS in positive-ion detection mode. ANITS-fatty acid derivatives gave an intense molecular ion peak at mlz [M+H](+); with MS/MS analysis, the collision-induced dissociation spectra of m/z [M+H](+) produced the specific fragment ions at mlz [M-345](+) and mlz 345.0 (here, m/z 345 is the core structural moiety of the ANITS molecule). The fluorescence excitation and emission wavelengths of the derivatives were lambda(ex) = 250 nm and lambda(em) = 512 nm, respectively. Linear correlation coefficients for all fatty acid derivatives are > 0.9999. Detection limits, at a signal-to-noise ratio of 3 : 1, are 24.76-98.79 fmol for the labeled fatty acids.
Resumo:
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.
Resumo:
A monolithic enzymatic microreactor was prepared in a fused-silica capillary by in situ polymerization of acrylamide, glycidyl methacrylate (GMA) and ethylene dimethacrylate (EDMA) in the presence of a binary porogenic mixture of dodecanol and cyclohexanol, followed by ammonia solution treatment, glutaraldehyde activation and trypsin modification. The choice of acrylamide as co-monomer was found useful to improve the efficiency of trypsin modification, thus, to increase the enzyme activity. The optimized microreactor offered very low back pressure, enabling the fast digestion of proteins flowing through the reactor. The performance of the monolithic microreactor was demonstrated with the digestion of cytochrome c at high flow rate. The digests were then characterized by CE and HPLC-MS/MS with the sequence coverage of 57.7%. The digestion efficiency was found over 230 times as high as that of the conventional method. in addition, for the first time, protein digestion carried out in a mixture of water and ACN was compared with the conventional aqueous reaction using MS/MS detection, and the former solution was found more compatible and more efficient for protein digestion.
Resumo:
The lytropic liquid crystals in dodecanic acid diethanolamine (DAD)/n-butanol (C4OH)/octane (n-C8H18)/deuteron (D2O) system were studied to determine the phase regions and were investigated by H-2-NMR spectroscopy,optical polarizing microscope and small-angle X-ray diffraction (SAXD) methods. The results indicate that the lamellar, hexagonal and cubic liquid crystals all exist in the above system. Keeping the weight ratio of DAD and C4OH constant,the microphase structure, H-2 quadruple splitting and the interlayer spacing are all changed with the addition of deuteron.
Resumo:
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。
Resumo:
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。
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水母雪莲属菊科植物,为名贵中药材其主要活性成分为黄酮类化合物。为解决雪莲资源其中匮乏,本文开展了利用水母雪莲细胞培养生产黄酮类活性成分的可行性研究。 采用目视法从水母雪莲原始愈伤组织中筛选得到白色、黄色和红色3种细胞系,其中黄色系的黄酮含量最高。利用γ射线辐射处理从红色系得高产黄酮细胞系。 证明了多种理化因子对水母雪莲培养细胞中黄酮类合成的调控作用。研究发现,温度和光照对水母雪莲愈伤组织黄酮合成影响较大。25℃是最佳培养温度;红光促进愈伤组织生长,蓝光促进黄酮的合成;进一步研究表明:光调节黄酮代谢途径第一步所需酶苯丙氨酸裂解酶(PAL)活性,PAL活性被红光所抑制,被蓝光所促进。碳源、氮源、植物激素对愈伤组织生长和黄酮形成影响较为显著。对MS培养基成分进行调整得到M-13培养基,在M-13培养基上培养的愈伤组织生长量和黄酮产量比MS培养基分别提高33%和82%。 首次建立水母雪莲细胞悬浮培养体系。确定了水母雪莲细胞悬浮培养的最适培养条件和最适培养基成分组成。摇床转速 90~120 r/min、接种量 2.5~4.0gDW/L、接种物种龄 8~10 d 对黄酮合成有利。调整MS培养基成分得到适合于培养水母雪莲悬浮细胞的生长培养基G和黄酮合成培养基MP,从而使细胞生长量与黄酮产量分别长比MS培养基提高32%和70%。 应用2-L搅拌式生物反应器对水母雪莲细胞进行了悬浮培养。TLC和HPLC分析表明,水母雪莲细胞培养物能够形成2种黄酮活性成分金合欢素和高车前素。本论文对水母雪莲细胞培养生产药用活性成分作了基础性工作。
Resumo:
本文通过对蓝细菌Synechocystis sp. PCC 6803在添加葡萄糖、Na2S203的BG-11培养基中的生长特性、脂类及脂肪酸组成、细胞低温荧光、色素组成进行分析测定,总结出如下规律: 当蓝细菌Synechocystis sp. PCC 6803在添加有葡萄糖的BG-11培养基中培养时细胞出现了一种新的糖脂(记为糖脂-x),在添加果糖、麦芽糖、乳糖等其它碳源的培养基中生长的细胞中也检测到糖脂-x糖脂-x的出现经推测是与活性氧相作用的产物,当在含糖的培养基中加入活性氧猝灭剂Na2S203时能有效地抑制糖脂-x的出现。糖脂一x的出现伴随着其它脂、尤其是双半乳糖甘油二酯(DGDG)的含量下降,这可能与细胞营养代谢类型的转变相适应。糖脂-x的出现使细胞适应异养生长条件,这时藻胆体(PBS),光系统II(PSII),光系统I(PSD降解,叶绿素消失。 糖脂-x经1H-NMR波谱术检测证实为甘油糖脂,经气质联谱分析其脂肪酸组成中含大量的枝链脂肪酸,12-甲基十四碳酸、12-甲基十五碳酸、12-甲基十六碳酸以及两种稀有的含氮脂肪酸。这些脂肪酸在添加高浓度葡萄糖的培养基中生长的.Synechocystis sp. PCC 6803中的单半乳糖甘油二酯(MGDG)也能检测到。ESI-MS以及P-SI-MS测定结果表明糖脂.x含一分子的脂酰基侧链以及两分子的己糖,半乳糖与葡萄糖。 对.Synechocystis sp. PCC 6803生长在不同浓度的葡萄糖与Na2S203培养基中脂类组成与脂肪酸组成进行比较,发现Na2S203能有效地增加膜脂中硫代异鼠李糖二酰基甘油(SQDG)和磷脂酰甘油(PG)的百分含量,培养基中同时添加葡萄糖时能抵消Na2S203的这一效应。此外,Na2S203能显著增加单半乳糖甘油二酯(MGDG)、双半乳糖甘油二酯(DGDG)中十六碳酸(C16:0)的百分含量,这一效应也能为葡萄糖恢复。Na2S203不能显著地改变SQDG中C16:0的百分含量,加入葡萄糖时能降低C16:0的百分含量。这些结果说明Na2S203可能充当一种还原剂使膜脂处于一种低的不饱和状态,同时加入葡萄糖时能降低Na2S203的还原力。此外,Na2S203还可作为SQDG合成中的硫供体。 用HPLC测定.Synechocystis sp. PCC 6803在添加不同浓度的Na2S203,葡萄糖的BG-11培养基中生长时的叶绿素与类胡萝卜素浓度,结果表明葡萄糖表现出对叶绿素与类胡萝卜素水平的抑制效应,Na2S203在低浓度时表现出对叶绿素与类胡萝卜素水平的促进效应,但在高浓度时表现出抑制效应。因此适当浓度的Na2S203的加入有利于维持蓝细菌在培养基中添加葡萄糖的生长条件下的低水平自由基,能使葡萄糖表现出促进细胞生长的特性。 通过测定Synechocystis sp. PCC 6803生长曲线中葡萄糖、Na2S203的浓度效应,结果表明葡萄糖在低浓度(例如5 mmoI.L-l)时表现出促进细胞的生长,在相对高的浓度表现出抑制细胞生长的效应。在培养基中同时加入Na2S203时可恢复葡萄糖对细胞的生长的促进效应。单独加入Na2S203表现出对细胞生长的抑制效应。这说明葡萄糖、Na2S203对细胞的生长存在着正的协同效应。
Resumo:
通过利用高效液相色谱-质谱联用技术,研究110 个不同基因型(包括3 个种和5 个种间杂种)葡萄品种的花色苷含量和成分特点。在所有品种中,最多鉴定出29 种花色苷。对葡萄的花色苷总量来说,一般情况下,欧亚种和欧美杂交种的花色苷含量较低,而野生种和砧木品种显著高于其它的种间杂种;在同一个种内,酿酒品种高于鲜食品种;在大多数高花色苷含量的种质中,二甲基花翠素类花色苷是主要的花色苷,而在低总花色苷量的品种,花青素类和花翠素类花色苷是主要的成分。此外,在欧亚种葡萄中,仅检测到单糖苷类花色苷,而在其它葡萄种质中,既有单糖苷花色苷又有双糖苷花色苷。在欧亚鲜食葡萄中,Pn-3-glucoside 是主要的花色苷,而在欧亚酿酒葡萄中,Mv-3-glucoside 是主要的花色苷。通过主成分分析,最终根据花色苷总量的不同和单、双糖苷含量的不同,110 个品种在散点图中被明显的分成3 部分。 通过连续两年调查3 个欧亚鲜食葡萄杂交组合的亲本和后代的花色苷含量来分析花色苷的遗传特点。共鉴定出16 种花色苷,且均为单糖苷类。母本中各花色苷的比例决定了后代中花色苷含量的比例,但是后代中花色苷的绝对含量不受亲本影响。不论亲本还是后代中,Peonidin 3-O-glucoside 和Malvidin3-O-glucoside 都是含量最高的花色苷。花色苷的有或无是寡基因控制的质量性状,而含量的多少是多基因控制的数量性状。通过主成分分析可以得知:在杂交后代中, peonidin 3-O-glucoside, malvidin 3-O-glucoside, delphinidin3-O-glucoside, cyanidin 3-O-glucoside, petunidin 3-O-glucoside, peonidin3-O-(6-O-coumaryl)-glucoside 和malvidin 3-O-(6-O-coumaryl)-glucoside 是影响果皮中花色苷总量的主要种类。花色苷的含量是一种高广义遗传力的性状,而且这种性状在两年间是稳定的(0.65-0.98)。 5 个不同基因型葡萄品种在成熟过程中果实品质的变化也被研究。始熟期开始后,果粒重量继续增加,果粒较大的鲜食品种增长很慢,而果粒较小的制汁和酿酒品种增长幅度很大;果实内两种主要的糖(葡萄糖和果糖)开始快速上升,且在整个成熟过程中保持1:1;有机酸的含量开始快速下降,苹果酸下降的幅度大于酒石酸。多酚物质在果实始熟期也发生巨大变化,花色苷快速积累。 ‘北紫’和‘梅鹿辄’中的花色苷在成熟前1-2 周达到最大值,‘黑奥林’、‘康可’和‘北醇’在整个成熟过程中花色苷一直增加;对非花色苷类多酚来说,‘黑奥林’和‘梅鹿辄’在果实成熟过程中一直增加,而在另3 个品种中是下降的;花色苷之间以及与黄酮醇之间成正相关,花色苷和酚酸成负相关关系,酚酸和黄酮醇也成负相关关系,黄烷醇物质之间以及与其它类黄酮物质之间成负相关关系。