反相高效液相色谱法测定鹿衔草中熊果酸和齐墩果酸的含量

建立反相高效液相色谱法测定鹿衔草中熊果酸和齐墩果酸含量,并进行方法学考察.采用Kromasil C18分析柱(4.6 mm×250 mm,5 μm);流动相为甲醇-水(88:12);柱温25 ℃;流速0.8 mL/min;检测波长210 nm.熊果酸进样量在0.922～18.44 μg,齐墩果酸进样量在0.506～10.12 μg范围内呈良好线性关系,其中熊果酸平均回收率为98.5%,RSD为2.13%(n=6);齐墩果酸平均回收率为 101.3%,RSD为1.69%(n=6).本方法使鹿衔草中主要成分熊果酸和齐墩果酸达到基线分离,操作简便、结果可靠,可为鹿衔草质量控制和评价提供有效手段.     

HPLC-DAD法测定血满草中熊果酸和齐墩果酸的含量(英文)

建立了HPLC-DAD法测定血满草中熊果酸和齐墩果酸含量,并进行方法学考察。采用HPLC-DAD进行分析,fusion-RP C18柱(4.6 mm×250 mm,4μm),甲醇-0.2%磷酸水溶液(90∶10)为流动相,检测波长210 nm,体积流量1.0 mL/min。同时采用微波辅助提取、回流提取、索氏提取、冷浸提取、超声提取五种方法对血满草中熊果酸和齐墩果酸含量进行测定并比较不同方法所得结果的差异,还比较了血满草不同部位中熊果酸和齐墩果酸的含量差异。测定结果表明熊果酸进样量在3.6～8.4μg范围内,齐墩果酸进样量在3.2～16μg范围内,呈良好线性关系。血满草中熊果酸和齐墩果酸平均回收率分别为98.3%和101.4%(n=5),相对标准偏差分别为1.13%和0.72%(n=5)。五种方法比较得出索氏提取得熊果酸和齐墩果酸含量最高;血满草花中熊果酸和齐墩果酸含量最高,而根中含量最低。该方法使血满草中熊果酸和齐墩果酸达到基线分离,操作简便,结果稳定可靠。     

苏州西山岛产枇杷叶的药材品质分析

枇杷叶为枇杷〔Eriobotrya japonica(Thunb.)Lindl.〕的干燥叶片,为常用中药材之一[1]。目前已从枇杷叶中分离得到三萜酸类、黄酮类及多酚类等多种有效成分[2-3],其中,三萜酸类是枇杷叶的主要药效物质,具有抗炎、降血糖和抗病毒等活性,主要包括齐墩果酸、熊果酸、蔷薇酸和科罗索酸等成分[4],目前已将齐墩果酸和熊果酸作为枇杷叶质量检测标准[1]。大量的分析结果[5-8]表明:不同产地、不同季节、落叶与生长叶和     

HPLC法同时测定鸡矢藤中熊果酸和齐墩果酸的含量

目的:建立高效液相色谱法同时测定鸡矢藤中熊果酸和齐墩果酸的含量。方法:色谱柱为DiamonsilTM C18(250×4.6 mm,5滋m),流动相为甲醇-0.05mol.L-1磷酸溶液(93∶7)为流动相,检测波长210 nm,进样量10滋L。结果:熊果酸在21.28滋g.mL-1～212.8滋g.mL-1范围内线性关系良好(r=0.9997),平均回收率为97.79%(RSD=1.30%);齐墩果酸在24.02滋g.mL-1～240.2滋g.mL-1范围内线性关系良好(r=0.9996),平均回收率为98.36%(RSD=1.11%)。结论:该方法简便、灵敏、准确,可用于鸡矢藤药材的质量评价。     

威灵仙药材中三萜苷元齐墩果酸含量的HPLC测定

为探索可用于威灵仙药材质量控制的三萜苷元齐墩果酸HPLC含量测定方法,用HPLC法测定了威灵仙药材中齐墩果酸含量。色谱柱:Kromasil C18(4.6×150 mm,5μm),检测波长:220 nm,流动相:甲醇-水(95:5),流速:0.5 mL/min。齐墩果酸在0.004~0.015 mg范围内线性关系良好,回归方程为:Y=437954101.73X 144588.26(R=0.9991),平均回收率为:98.33%,RSD=1.76%。样品中齐墩果酸含量分别为:东北铁线莲0.2281%;威灵仙0.1260%、棉团铁线莲0.1851%。本方法快速、准确、灵敏度高、重现性好,适用于对威灵仙中齐墩果酸的含量进行测定。     

HPLC法同时测定鸡矢藤中熊果酸和齐墩果酸的含量

目的：建立高效液相色谱法同时测定鸡矢藤中熊果酸和齐墩果酸的含量。方法：色谱柱为DiamonsilTM C18（250×4.6 mm,5滋m）,流动相为甲醇-0.05mol.L-1磷酸溶液（93∶7）为流动相,检测波长210 nm,进样量10滋L。结果：熊果酸在21.28滋g.mL-1～212.8滋g.mL-1范围内线性关系良好（r=0.9997）,平均回收率为97.79%（RSD=1.30%）;齐墩果酸在24.02滋g.mL-1～240.2滋g.mL-1范围内线性关系良好（r=0.9996）,平均回收率为98.36%（RSD=1.11%）。结论：该方法简便、灵敏、准确,可用于鸡矢藤药材的质量评价。     

女贞子提取物主要活性组分及其抗丙型肝炎病毒复制活性分析

中药女贞子(Ligustrum lucidum,LL)具有肝保护和抗炎症作用.本研究分析女贞子提取物对丙型肝炎病毒(hepatitis C virus, HCV)复制的影响及其活性成分. 薄层层析法分离女贞子水提取物,获得5个分离组分. Real-time RT-PCR 和Western印迹发现,分离组分1和2 抑制HCV JFH1细胞感染模型中的JFH1病毒复制. 分离组分的高效液相色谱(high-performance liquid chromatography,HPLC)分析表明,熊果酸和齐墩果酸可能是组分1 和 2的抗病毒活性成分. 熊果酸和齐墩果酸抗病毒实验发现,熊果酸和齐墩果酸抑制HCV JFH1的复制,它们的选择指数 (SI) 分别为 6.7 和30.8. 这些研究结果表明,女贞子及其化学成分熊果酸和齐墩果酸具有潜在的丙型肝炎治疗价值.     

枇杷花中三萜类物质的分析与评价

为评价枇杷[Eriobotrya japonica(Thunb.)Lindl.]花中三萜类物质的组成特点,采用HPLC法对53份代表性枇杷种质花中的科罗索酸、熊果酸和齐墩果酸的含量进行了测定。结果表明,枇杷花中3种三萜类物质含量平均为0.439%,其中科罗索酸、熊果酸和齐墩果酸分别占19.1%、65.6%和15.3%。不同枇杷种质资源中三萜类物质含量存在丰富多样性,以科罗索酸含量的变异系数最大(29.34%),齐墩果酸含量差异最大(最高和最低分别相差6.7倍)。来源于广东的枇杷花中科罗索酸和齐墩果酸含量变异最大,而来源于云南的枇杷花熊果酸含量变异最大。根据枇杷种质资源花中三萜类物质含量聚类分析,提出了高、中、低分级指标。在8个主栽枇杷良种中贵妃和长红3号花中三萜类物质含量处于高含量区位。因此,经综合筛选,三萜类物质含量高的枇杷种质有3份:贵妃、香钟1号和长红3号。     

219份枣种质资源果实三萜酸含量分析

以219份枣种质脆熟期果实为试材,采用超高效液相色谱(UPLC)法检测不同枣种质果实中的山楂酸、桦木酸、齐墩果酸和熊果酸4种三萜酸组分含量,并进行描述统计分析、相关性分析和聚类分析,进而筛选三萜酸含量较高的优特异种质。结果表明:(1)枣果中总三萜酸(TTA)含量的变化范围95.72~737.82μg·g^-1,平均值306.83μg·g^-1,变异系数为29.02%,含量最高的为‘大荔小圆枣’。4种组分以山楂酸含量最高,其次为桦木酸,齐墩果酸和熊果酸含量较低,各组分在不同枣种质中都存在丰富的遗传多样性,其中熊果酸变异系数最高(60.75%)。(2)正态性检验结果表明,各种质的山楂酸、桦木酸和总三萜酸含量服从正态分布,齐墩果酸和熊果酸含量不服从正态分布。(3)相关性分析结果显示,总三萜酸含量与4个组分均呈极显著正相关关系,组分间也存在相关性,山楂酸含量与桦木酸呈极显著正相关关系,桦木酸含量与齐墩果酸呈极显著正相关关系,齐墩果酸含量与熊果酸呈极显著正相关关系。(4)聚类分析将219份枣种质划分为4大类群,分别为熊果酸含量最高的类群,齐墩果酸和熊果酸含量较高类群,各组分中低含量类群以及山楂酸、桦木酸和总三萜酸含量较高类群。(5)筛选出13份各组分或总三萜酸含量较高的优特异种质,为枣三萜酸相关功能产品的开发提供原料选择。     

伊犁杂花薰衣草叶化学成分研究

目的:对新疆伊犁杂花薰衣草叶的化学成分进行分离和鉴定。方法:用95%乙醇加热回流提取,萃取物上硅胶柱进行分离纯化,根据理化性质,并利用质谱(MS)和核磁共振(NMR)技术确定其结构。结果:从伊犁薰衣草叶的乙酸乙酯部位分离出了2个化合物,鉴定为β-谷甾醇(Ⅰ),香豆素(Ⅱ);正丁醇部位分离出了3个化合物,鉴定为熊果酸(Ⅲ)、齐敦果酸(Ⅳ)、咖啡酸(Ⅴ)。结论:香豆素(Ⅱ)、齐墩果酸(Ⅳ)为首次从该植物中分离得到。     

氨基酸分析仪测定饲料添加剂——叶酸的方法

用６ｍｏｌ／Ｌ盐酸于１１０℃条件下水解饲料添加剂——叶酸,使之游离出谷氨酸,用氢氧化钠中和调节ｐＨ到２,氨基酸分析仪测定谷氨酸含量,经与标准叶酸水解样品比较,计算出叶酸的纯度。该方法重现性好,变异系数ＣＶ＝０．０８％,平均回收率为９８．３４％,浓度与峰面积呈线性相关,相关系数ｒ＝０．９９８７,可随氨基酸分析同时进行,不需改变任何分析条件。     

丙酮酸对细菌L-乳酸发酵的促进作用

研究了丙酮酸在不同浓度和添加时间对LactobacilluscaseiL 乳酸发酵过程中葡萄糖转化率和L 乳酸产量的影响。结果表明 ,当丙酮酸的添加量为 30g·L- 1 时 ,L 乳酸的产量达到 74g·L- 1 。在 72h的发酵周期内 ,丙酮酸在 2 4h和 42h添加的效果好于其他时间添加。     

Purification and Characterization of the Heat-Stable Factors Essential for the Conversion of Lignoceric Acid to Cerebronic Acid and Glutamic Acid: Identification of N-Acetyl-l-Aspartic Acid

Abstract: The conversion of lignoceric acid to cerebronic acid, ceramides, cerebrosides, and glutamic acid is catalyzed by a rat brain particulate preparation. The heat-stable factor, prepared from calf cerebellum, together with the heat-labile factor, a pyridine nucleotide, and Mg²⁺ are essential to all of these metabolic pathways. Our previous work showed that the heat-stable factor is composed of at least two components, HSF-1 and HSF-2, and identified HSF-2 as d -glucose-6-phosphate. In the current investigation, HSF-1 was further purified and found to be N -acetyl- l -aspartic acid. In addition, it was discovered that a third component, HSF-3, is also required for heat-stable factor activity. A reconstituted system composed of N -acetylaspartic acid, glucose-6-phosphate, and HSF-3 fully replaced the heat-stable factor essential for the conversion of lignoceric acid to cerebronic acid and glutamic acid. The reconstituted heat-stable factor did not show the initial time lag always observed with the crude heat-stable factor.     

生物催化富马酸加氨合成天门冬氨酸的研究进展

天门冬氨酸是构成蛋白质的基本氨基酸之一,也是一种重要的医药工业原料。天门冬氨酸酶催化富马酸加氨合成天门冬氨酸。本文从天门冬氨酸酶的结构与性质、产酶菌的筛选与培养条件优化、酶促反应动力学研究、酶的分子生物学研究4个方面介绍了国内外关于生物转化合成天门冬氨酸的研究概况。     

Blood-Brain Barrier Produces Significant Efflux of L-Aspartic Acid but Not D-Aspartic Acid

The brain efflux index method has been used to clarify the mechanism of efflux transport of acidic amino acids such as L-aspartic acid (L-Asp), L-glutamic acid (L-Glu), and D-aspartic acid (D-Asp) across the blood-brain barrier (BBB). About 85% of L-[3H]Asp and 40% of L-[3H]Glu was eliminated from the ipsilateral cerebrum within, respectively, 10 and 20 min of microinjection into the brain. The efflux rate constant of L-[3H]Asp and L-[3H]Glu was 0.207 and 0.0346 min(-1), respectively. However, D-[3H]Asp was not eliminated from brain over a 20-min period. The efflux of L-[3H]Asp and L-[3H]Glu was inhibited in the presence of excess unlabeled L-Asp and L-Glu, whereas D-Asp did not inhibit either form of efflux transport. Aspartic acid efflux across the BBB appears to be stereospecific. Using a combination of TLC and the bioimaging analysis, attempts were made to detect the metabolites of L-[3H]Asp and L-[3H]Glu in the ipsilateral cerebrum and jugular vein plasma following a microinjection into parietal cortex, area 2. Significant amounts of intact L-[3H]Asp and L-[3H]Glu were found in all samples examined, including jugular vein plasma, providing direct evidence that at least a part of the L-Asp and L-Glu in the brain interstitial fluid is transported across the BBB in the intact form. To compare the transport of acidic amino acids using brain parenchymal cells, brain slice uptake studies were performed. Although the slice-to-medium ratio of D-[3H]Asp was the highest, followed by L-[3H]Glu and L-[3H]Asp, the initial uptake rate did not differ for both L-[3H]Asp and D-[3H]Asp, suggesting that the uptake of aspartic acid in brain parenchymal cells is not stereospecific. These results provide evidence that the BBB may act as an efflux pump for L-Asp and L-Glu to reduce the brain interstitial fluid concentration and act as a static wall for D-Asp.     

Amino Acid Neurotransmitters in the CNS: Properties of Diaminobutyric Acid Transport

Uptake of L-2,4-diaminobutyric acid (DABA), a positively charged analogue of gamma-aminobutyric acid (GABA), by a synaptosomal fraction isolated from rat brain occurred with a Km of 54 +/- 12 microM and a Vmax of 1.3 +/- 0.2 nmol/min/mg protein. The transport of DABA was inhibited competitively by GABA whereas that of GABA was affected in the same manner by addition of DABA. The maximal accumulation of DABA ([DABA]i/[DABA]c) was observed to increase as the second power of the transmembrane electrical potential ([K+]i/[K+]e) and the first power of the sodium ion concentration gradient. These findings indicate that DABA is transported on the GABA carrier with a net charge of +2, where one charge is provided by the cotransported Na+ and the second is contributed by the amino acid itself. Since uptake of GABA, an electroneutral molecule, is accompanied by transfer of two sodium ions, the results obtained with DABA suggest that one of the sodium binding sites on the GABA transporter is in proximity to the amino acid binding site.     

Sulfur Amino Acid Metabolism in the Developing Rhesus Monkey Brain: Subcellular Studies of Taurine, Cysteinesulfinic Acid Decarboxylase, γ-Aminobutyric Acid, and Glutamic Acid Decarboxylase

Abstract: Taurine, cysteinesulfinic acid decarboxylase (CSAD), glutamate, γ-aminobutyric acid (GABA), and glutamic acid decarboxylase (GAD) were measured in subcellular fractions prepared from occipital lobe of fetal and neonatal rhesus monkeys. In addition, the distribution of [³⁵S]taurine in subcellular fractions was determined after administration to the fetus via the mother, to the neonate via administration to the mother prior to birth, and directly to the neonate at various times after birth. CSAD, glutamate, GABA, and GAD all were found to be low or unmeasurable in early fetal life and to increase during late fetal and early neonatal life to reach values found in the mother. Taurine was present in large amounts in early fetal life and decreased slowly during neonatal life, arriving at amounts found in the mother not until after 150 days of age. Significant amounts of taurine, CSAD, GABA, and GAD were associated with nerve ending components with some indication that the proportion of brain taurine found in these organelles increases during development. All subcellular pools of taurine were rapidly labeled by exogenously administered [³⁵S]taurine. The subcellular distribution of all the components measured was compatible with the neurotransmitter or putative neuro-transmitter functions of glutamate, GABA, and taurine. The large amount of these three amino acids exceeds that required for such function. The excess of glutamate and GABA may be used as a source of energy. The function of the excess of taurine is still not clear, although circumstantial evidence favors an important role in the development and maturation of the CNS.     

乳酸菌酸胁迫反应机制研究进展

乳酸菌可发酵糖类产生乳酸,并广泛应用于食品、药物和饲料等工业。由于有机酸的积累,乳酸菌大部分的生长代谢都在低pH的酸性环境中进行,具有酸胁迫反应。pH的自我平衡、ATR反应机制、对大分子的保护和修复作用及细胞膜的变化等是乳酸菌酸胁迫反应的主要机制,其中,pH自我平衡包括F0F1-ATPase质子泵、精氨酸脱氨酶途径(ADI)和谷氨酸脱羧酶途径(GAD)等。由此可见,乳酸菌酸胁迫反应机制涉及到基因和蛋白的表达调控等,是非常复杂的网络调控体系。     

解淀粉乳酸细菌在L-乳酸发酵生产中的应用

对解淀粉乳酸细菌及其产生的淀粉酶和发酵工艺等方面的国内外研究现状进行了综述。解淀粉乳酸细菌具有分泌淀粉酶的能力,可免去原料水解处理工序直接发酵淀粉质原料生产乳酸,可以简化生产工艺,并可节约设备投资,进而降低生产成本。解淀粉乳酸细菌主要分离自传统发酵食品,也可从有机废弃物和厨余垃圾中分离得到。介绍了解淀粉乳酸细菌直接利用淀粉质原料的机理,比较了解淀粉乳酸菌发酵生产L-乳酸的工艺。提出通过诱变育种和基因工程育种等方法获得更加高效的解淀粉乳酸细菌,并结合先进的发酵、分离技术来提高乳酸生产效率。     

紫锥菊单咖啡酰酒石酸和菊苣酸提取工艺优化

采用正交试验设计,选取乙醇体积浓度百分比、提取温度、提取时间、抗氧化剂用量等因素,优化紫锥菊Echinacea purpurea单咖啡酰酒石酸和菊苣酸的加热回流提取工艺,并考察加入抗氧化剂对提取效果的影响。结果表明,优化的提取条件是以25%乙醇,在80 ℃回流提取90 min。抗氧化剂用量对提取效果影响不显著。优化后的加热回流提取条件对紫锥菊单咖啡酰酒石酸和菊苣酸的提取均适用,提取中无需加入抗氧化剂。