麝香中脂溶性成分的提取与麝香质量鉴别

采用薄层层析和气相色谱技术,比较了超声、冷浸和热回流3种提取方法及乙醇、乙醚、正己烷3种溶剂对麝香提取液中脂溶性成分及麝香酮含量的影响。结果显示用不同提取方法和溶剂提取的麝香脂溶性成分经薄层层析后均呈现6或7个斑点。而经气相色谱分析,其结果却有较大的差别,麝香乙醚提取液的色谱峰较乙醇和正己烷更丰富,超声提取的效果较冷缦和热回流好,色谱峰达到20个。麝香酮的定量分析显示冷浸法提取的麝香酮含量高于超声和热回流提取。通过薄层层析和气相色谱分析,对10个麝香样品的质量进行了鉴别。     

纤维素板微量氨基酸的分离及几种显色方法的比较

氨基酸分析是研究蛋白质化学的最基本的实验技术之一。现在已经普遍地使用离子交换层析、纸层析、纸电泳、薄层层析等方法分离、分析氨基酸。其中自动化的离子交换层析方法分析具有快速、微量和准确等特点,但需要昂贵的仪器设备,在一般实验室里不易办到。纸层析和薄层层析的方法,设备要求简单,操作方便,操作熟练时也可达到定量的要求。也可以用纤维素薄层层析的方法分离分析氨基酸,并已用于尿和血样品以及其他蛋白质中的氨基酸测定。经我们初步摸索,使用一种小型的纤维素板层析,并将茚三酮试剂直接加入展层溶剂中,蛋白质经酸水解后,可得到完全分开的普通     

一种简便的肌醇磷脂微量分析方法

分析磷脂酰肌醇循环(PI cycle)的磷脂组分常采用双向薄层层析法．建立了一个简单快速的单向薄层层析分离肌醇磷脂方法．首先采用不同的有机溶剂体系分别提取非多磷酸肌醇磷脂和多磷酸肌醇磷脂,然后用不同的层析展开体系,对两部分磷脂进行单向薄层层析分离．采用无载体 ³²P标记实验对该方法分离效果进行了观察．此法适用于同位素标记和非标记样品中肌醇磷脂组分的比较分析及多磷酸肌醇磷脂的提取、纯化和定量．     

第12届国际生物奥林匹克竞赛实验试题(2)

(续 2 0 0 2年第 3期第 6 0页 )实验 3:植物色素分析光合色素的反向薄层析 (TL C)引　言　　薄层层析是分子分析的 1种重要技术 ,生物学家和生物化学家如何了解一些分子 (如蛋白质、脂肪和植物色素 )呢 ?回答这些问题是通过分离和研究这些分子 ,这已经有 10 0多年的历史了 ,分析这些分子的 1种重要技术是薄层层析 (TLC)。这种技术能够分离不同类型的分子是基于这些分子有亲水固定相和疏水流动相对亲和性 ,固定相通常是固定在玻璃板或金属板上的硅胶 ,而流动相是适当溶剂的混合物。虽然现在已被一些新的更有效的精确的技术所取代 (如用 G…     

毛纺织品中辛硫磷含量的两种测定方法

辛硫磷作为纯毛纺织品的防蛀药剂,经一年试验已初步证实有效。为了找出辛硫磷合理使用的有效浓度,我们采用了薄层层析显色法和酶抑制法进行了测定,效果较好。可供有机磷农药残留量分析的参考。 一、薄层层析显色法 (一)提取 称毛织品2克(可根据辛硫磷含量而     

生物碱成分常用显色剂及一种检测内酰胺的特效方法

薄层层析 (TLC)中 ,碘化铋钾和改良碘化钾试剂常作为生物碱成分 (天然和合成化合物 )的显色剂。本文对它们进行综述、分析 ,以期对生物碱成分的薄层层析提供参考。同时提供一种检测γ 内酰胺的特效方法。     

江苏省植生学会举办“植物激素实验技术培训班”

江苏省植物生理学会,委托南京林产工业学院植物生理教研组,于1983年10月15—25日,举办了“植物激素实验技术培训班”。这期培训班的主要特点是:1.时间短、内容多。在短短的10天内,学习了以嫩扁豆为材料的IAA、GA、CTK、ABA四种激素的提取分离、溶液萃取、离子交换、纸层析、薄层层析、生     

铁扫帚中总多糖提取工艺的研究

研究了铁扫帚中总多糖提取的最佳工艺,并对其进行了薄层层析,结果表明:A3B2C1条件下,总多糖提取率最高。薄层层析得两个组分,其Rf值分别为:0.65和0.55     

GM_3在几种哺乳动物肝脏和狗红细胞中的含量及其分离纯化

从正常兔、猪和狗的肝脏及狗红细胞中分离纯化了总神经节苷脂,测定了脂结合唾液酸,进行了高效薄层层析,比较了上述四种组织中GM_3的含量。结果表明狗红细胞中的GM_3的含量较另三种的高,狗肝和兔肝次之,猪肝含量甚微。从狗红细胞中提取和纯化了GM_3,其得量为每毫升压积红细胞351.0μg,纯度为92.2％。     

青海弧菌Q67自体诱导物的检测及其对菌体发光的影响

青海弧菌Q67是一种我国新近确定的淡水发光细菌,其发光强度随毒物浓度改变的特性使其可作为水质检测的指示菌株。利用生物检测菌株快速检测、C18反相薄层层析和β-半乳糖苷酶含量测定,证实了该菌存在LuxI-LuxR型群体感应系统,并产生N-酰基高丝氨酸内酯类自诱导物。进一步的实验表明,该信号分子活性随生长阶段有较大变化,其粗提物不仅能调控菌体的生物发光,对菌体生长繁殖也产生较大影响。     

Protein-binding assay for cyclic AMP: possible interference by traces of trichloroacetate.

When cyclic AMP is to be extracted from animal and plant tissues a 5% trichloroacetic acid (TCA) solution is often used as the initial extraction medium. We have shown that traces of trichloroacetate remain in the extract even after multiple solvent extraction and this impurity can cause inflated estimates of cyclic AMP (cAMP) in the protein-binding assay. This will only occur when it is necessary to employ relatively large volumes of TCA (i.e., tissues containing low levels of cAMP). For such tissues we recommend the use of a thin layer chromatographic purification stage to separate cAMP from the trichloroacetate residue.     

Enhanced solvent extraction of polar lipids associated with rubber particles from Hevea brasiliensis

Biochemical studies of lipids bound to rubber particles have been complicated due to the solubility of polyisoprene chains in most extracting solvents and the rather delicate nature of polar lipids that are often denatured when traditional solvent extraction techniques are employed. In this paper, we describe a traditional technique and accompanying solvents that permit optimal extraction of rubber particle bound lipids. The technique, which is validated after characterizing the lipid extracts by elemental analysis, silica column adsorption and thin layer chromatography, appeared more suitable for extracting total lipids with optimal glycolipid and phospholipid contents. This technique is proposed as an alternative to traditional extraction methods used for solid natural rubber as it offers advantages with respect to ease of application, extract quality, extraction yields and reproducibility.     

Nature of the phosphotungstic acid-chromic acid (PACP) stain for plasma membranes of plants and mammalian sperm.

The selective staining of plasma membranes of plants and porcine spermatozoa given by a mixture consisting of 1% phosphotungstic acid in 10% chromic acid (PACP) applied following periodic acid destaining of glutaraldehyde-osmium tetroxide-fixed electron microscope sections is reduced or eliminated by prior extraction of the tissues with lipid solvents, including ethanol. The ethanol-soluble fraction of sperm contains constituents which restore the PACP-staining reaction when added to ethanol-extracted and lyophilized sperm. Analysis of the ethanol extracts by thin layer chromatography revealed two major components which reacted with both phosphotungstic acid (PTA) and alpha-naphthol detection reagents. These PTA-positive constituents were concentrated in plasma membranes of sperm; components with similar mobilities were found in fractions of plasma membranes from plants. Addition of the PTA-positive constituents from either sperm or plants to extracted and lyophilized sperm restored the PACP staining. The findings are interpreted to mean that one or more low molecular weight constituents (saccharides or glycolipids), rather than glycoproteins, concentrated in plaslma membranes are responsible for the unique PACP staining in both plants and porcine sperm.     

Determination of individual conjugated bile acids in human bile

A method has been developed and validated for the determination of the six major conjugated bile acids, cholesterol, and total phospholipids in bile of human subjects previously injected with 4-(14)C-cholesterol. The procedure is designed for use with 5-10 ml of duodenal or T-tube bile and eliminates difficulties associated with existing methods for bile acid determination, in particular the requirement for preliminary saponification under pressure or the use of paper chromatography. Saponification under pressure is employed only in steps where partial destruction of the steroid moiety of conjugated bile acids is not a crucial matter. A preliminary Folch extraction and washing step separated free cholesterol and phospholipids (bottom layer) from the six major conjugated bile acids (top layer). The conjugated bile acids were then fractionated cleanly by thin-layer chromatography to give four groups, the (14)C content of each of which was determined. A second aliquot of the top layer was used to determine (after deconjugation) the radioactivity ratio of deoxycholic acid to chenodeoxycholic acid for the two unresolved groups (dihydroxycholanoic acid conjugates with glycine and taurine, respectively). A third aliquot was used for determination of specific activities of the methyl esters of cholic, chenodeoxycholic, and deoxycholic acids derived from the total bile salts. Appropriate calculations yielded the concentration in bile of all six major bile acid conjugates.     

应用薄层层析技术快速检出杂色曲霉素产毒菌株

直接硅胶板薄层层析快速检出杂色曲霉素产毒菌株,简化了培养、萃取纯化等繁琐步骤,大大缩短样品检测所需时间,做到快速灵敏。检验时取生长待测菌株的琼脂块,直接以硅胶薄层板展开浸出溶液,显色后产毒株色谱带中毒素斑点清晰易辨。所用试剂、设备简单,费用低廉,容易掌握。尤其适用于大量菌株的分离筛选。应用此方法,检测了222个真菌菌株的产毒能力。     

薄层色谱和高效液相色谱联用测定暗纹东方鲀肌肉中肌肽和谷胱甘肽的含量

通过薄层色谱(TLC)与高效液相色谱(HPLC)联用技术鉴定了暗纹东方鲀(Takifugu obscurus)肌肉中存在肌肽和谷胱甘肽,同时利用高效液相色谱法测定了肌肽和谷胱甘肽(GSH)的含量。薄层层析采用的展开剂为正丁醇:乙酸:水(4∶2∶1),层析板为硅胶板。高效液相色谱利用Kromasil C18反相柱分析,流动相为10%的纯乙腈和90%含有0.05%三氟乙酸的超纯水。结果表明:通过薄层色谱和高效液相色谱鉴定了暗纹东方鲀肌肉中肌肽和谷胱甘肽,其中暗纹东方鲀肌肉中肌肽含量约213μg/g(鲜重),还原性谷胱甘肽含量约211μg/g(鲜重)。本法样品无需衍生,操作简便,适合于暗纹东方鲀肌肉中肌肽和谷胱甘肽的测定。本文为生物体内肌肽和谷胱甘肽的研究提供借鉴意义。     

Distribution of actin filaments in fertilized egg of the ascidian Ciona intestinalis

Microfilaments in the contracting cortex during the bipolar ooplasmic segregation of Ciona intestinalis eggs were examined by two methods, staining with fluorescent phalloidin and decoration with myosin subfragment 1 (S1). Fluorescent (Fl-)phalloidin revealed prominent fluorescence in the contracting cortex between the surface constriction and the vegetal pole of fertilized eggs. The animal pole did not stain. After extraction in Triton X-100, the cortex appeared as a thin layer that easily separated from cytoplasmic mass, especially at the contracting stage after fertilization. This layer also stained strongly with Fl-phalloidin. S1-decoration confirmed that actin filaments were abundant in the thin layer of Triton-extracted cortex. The actin filaments are considered to compose a contractile network covering the vegetal side of the constriction.     

Development of a high-performance liquid chromatography method for the simultaneous quantification of four organoarsenic compounds in the feeds of swine and chicken

A high-performance liquid chromatography (HPLC) method with UV detection was developed for the simultaneous determination of arsanilic acid, roxarsone, nitarsone, and carbarsone in the feeds of swine and chicken. Feed samples were extracted with methanol/1% acetic acid (90:10, v/v) in an ultrasonic bath and the protein was precipitated with 2% Cu(2)SO(4). The samples were further purified by solid phase extraction (SPE) on SAX cartridges. Separation was performed on a Zorbax SB-Aq C18 HPLC column using an isocratic procedure with methanol and 1% acetic acid (3:97, v/v) at a flow-rate of 0.7 mL min(-1), and the UV detector was set at a wavelength of 260 nm. The recoveries of organoarsenic compounds spiked at levels of 2, 20 and 200 μg g(-1) ranged from 81.2% to 91.3%; the inter-day relative standard deviation values were less than 7.0%. The limits of quantification for four organoarsenic compounds were 1.0-2.0 μg g(-1). This simple and fast method could be applied to the determination of multi-residues of organic arsenic compounds in animal feeds.     

Determination of trace lead in biological and water samples with dispersive liquid-liquid microextraction preconcentration

A new method for the determination of trace lead was developed by dispersive liquid–liquid microextraction preconcentration and graphite furnace atomic absorption spectrometry. In the proposed approach, 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) was used as a chelating agent, and carbon tetrachloride and ethanol were selected as extraction and dispersive solvents. Some factors influencing the extraction efficiency of lead and its subsequent determination, including extraction and dispersive solvent type and volume, pH of sample solution, concentration of the chelating agent, and extraction time, were studied and optimized. Under the optimum conditions, the enrichment factor of this method for lead was reached at 78. The detection limit for lead was 39 ng L⁻¹ (3σ), and the relative standard deviation (RSD) was 3.2% (n = 7, c = 10 ng mL⁻¹). The method was successfully applied to the determination of trace amounts of lead in human urine and water samples.