高效液相色谱法在脱氧核糖核酸酶解动力学

为了更好地对脱氧核糖核酸酶解动力学过程进行研究,建立脱氧核糖核酸(DNA)酶解液中4种脱氧核苷酸(腺嘌呤脱氧核苷酸(dAMP)、鸟嘌呤脱氧核苷酸(dGMP)、胞嘧啶脱氧核苷酸(dCMP)、胸腺嘧啶脱氧核苷酸(dTMP))的高效液相测定方法,能将酶解液中4种脱氧核苷酸完全分离并准确定量.在此基础上,对DNA酶解的动力学进行初步研究,其反应机理为不存在底物和产物抑制的双底物顺序反应,动力学方程为x=1/bln(1+abt)(其中a=0.372 3ρ0-0.974;b=-0.049 3ρ20+1.115 3ρ0 - 1.110 3),该方程可以很好地描述DNA酶解过程,误差仅为3.31%.     

高效液相色谱法测定辣椒素

用９５％醋酸钠饱和乙醇溶液抽提辣椒树脂油中的辣椒素,经高效液相色谱分离,在紫外长２８０ｎｍ处测定。用此法分析测得福建特产“小米椒”的辣椒素含量为１０．３８％。     

高效液相色谱测定血小板cAMP-磷酸二酯酶活力

本文报道了离子交换高效液相色谱-紫外检测磷酸二酯酶(PDE)活力的方法。本方法的回收率为93.02±2.09％,重复性CV为3.16％,5’-AMP在17.0—90.7pmol/10μl、cAMP在138—1104pmol/10μl浓度范围内,相关系数分别为0.9986和0.9950。用5’-AMP生成率和cAMP的转化率表达PDE活力,两者吻合。本方法能灵敏地反映茶碱对PDE的抑制作用。     

高效液相色谱法分离测定香兰素

用６０％乙醇提取香荚兰豆的香兰素,经高效液相色谱法分离,在紫外波长３３０ｍｍ处测定,选取适当的流动相,能快速,准确地测定出香兰素,最低检测含量可达到０．０１μｇ．     

高效液相色谱法测定超滤后血浆中的谷氨酰胺

用高效液相色谱法测定超滤后血浆中的谷氨酰胺, 平均回收率为96.75%, 在130～1300μmol/L范围内呈线性关系(r=0.9906), 健康人正常值男性为(694.97±102.31)μmol/L, 女性为(623.79±99.27)μmol/L, 男女间值有显著差别(P＜0.05)该分析方法简单、迅速, 可用于外科肠道内营养的监测和对肠粘膜结构与功能的研究.     

硫解高效液相色谱法快速检测原花青素

为开发一种苄硫醇分解-高效液相色谱检测原花青素的新方法,本研究制备并纯化了苄硫醚-表儿茶素和苄硫醚-表儿茶素没食子酸酯,并与没食子酸、儿茶素、表儿茶素和表儿茶素没食子酸酯为对照品,在新的色谱条件下6种硫解产物可在11 min之内完成分离,外标法定量分析RSD均小于1.86%(n=5),最低检出限为0.5～1.5 ng,在1 ng～960 ng之间线性关系良好(r≥0.9996),平均回收率77.8%～94.6%。这种方法可用于植物及其提取物中原花青素含量及平均聚合度的快速分析。     

高效液相色谱法测定辣椒素

用95%醋酸钠饱和乙醇溶液抽提辣椒树脂油中的辣椒素,经高效液相色谱(HPLC)分离,在紫外波长280 nm处测定。用此法分析测得福建特产"小米椒"的辣椒素含量为10.38%。     

鲇胃肠道、胰脏对7种饲料蛋白质的酶解动力学

饲料蛋白质在鱼体消化道内经过消化酶分解为氨基酸、小肽等小分子物质后才被利用。施用辉等 1 认为寡肽的释放量与饲料蛋白质的品质呈正相关关系。       

The study of granulocyte kinetics by mathematical analysis of DNA labelling

Summary A commonly used experimental procedure for the study of granulocyte kinetics involves the labelling and subsequent tracing of granulocyte DNA. Following the introduction of a label into the system, observations are made periodically on the concentration of label in the DNA of granulocytes taken from the circulating blood. A mathematical model for the expected value of this concentration (expressed as a function of time following label introduction) has been derived, studied, and related to experimental observations from studies using P³² as a label. Insofar as the derivation of the model accurately incorporates the relevant aspects of granulocyte kinetics, the model will be useful in the interpretation of the experimental observations in terms of these kinetics.Among other things, study of the model indicates that the assumption of flash labelling made with respect to some labels is quite crucial and needs to be examined critically. It has also been necessary to make adjustments to allow for the observed emergence of labelled cells from the marrow soon after label introduction. In addition, despite a high degree of confounding of parameter effects it has been possible to suggest bounds on some of the parameters of the model for some species. The bounds will be refined as the model is improved and more data become available. Study and development of the model continues with particular interest in generalizations to include the diseased state chronic granulocytic leukemia.This work was presented in part to the Annual Meeting of the Institute of Mathematical Statistics, The American Statistical Association and The Biometric Society, Washington, D. C. December 1967.Dr.Walker is the recipient of Research Career Development Award 1 —K3 —CA —9554 from the National Cancer Institute.     

不同产地野菊花中黄酮类成分含量的HPLC分析

野菊花为菊科(Compositae)植物野菊[Dendranthema indicum (L.) Des Moul.]的头状花序,具有清热解毒和疏风散热等功效.黄酮类化合物为野菊花最主要的有效成分之一,最早从野菊花中分离出的黄酮类化合物为木犀黄酮苷,此后相继得到刺槐素、木犀草素、芹菜素和蒙花苷等黄酮类化合物,以蒙花苷和木犀草素含量最高,其中蒙花苷含量是野菊花药材的主要质量检测指标[1].     

Direct enantioselective HPLC monitoring of lipase‐catalyzed kinetic resolution of flurbiprofen

The solvent versatility of Chiralpak IB, a 3,5‐dimethylphenylcarbamate derivative of cellulose‐based chiral stationary phase, is demonstrated in the direct enantioselective HPLC monitoring of lipase‐catalyzed kinetic resolution of flurbiprofen in nonstandard HPLC organic solvents. Nonstandard HPLC organic solvents were used as the reaction media for the lipase‐catalysis and in mean time as diluent to dissolve the “difficult to dissolve” enzyme substrate (the acid) and as eluent for the simultaneous enantioselective HPLC baseline separation of both substrate and product in one run without any further derivatization. Chirality 2010. © 2009 Wiley‐Liss, Inc.     

漆树8个品种和5个野生居群HPLC指纹图谱分析

采用HPLC指纹图谱技术分析了陕西漆树8个品种和5个野生居群的树皮提取物化学成分,并以提取物中6个化学成分含量为变量进行聚类分析.结果表明:(1)通过对2、3、4和5号主要特征峰分析,漆树8个品种和5个野生居群的13个样品平均相似度为0.974;方差和变异系数分析显示,各主要特征峰含量、漆酚总量之间存在差异,且变异系数最大达61.49%.(2)聚类分析结果显示,依据漆酚总量等6个变量完全可将漆树8个品种的8个样品分开,表明单烯漆酚为区分8个样品的第一关键因子,未知化合物和二烯漆酚为第二、第三关键因子.同时,采自商南的2个漆树品种样品和采自平利的6个品种样品分别聚为两类,表明其聚类结果与漆树地理分布存在密切关系.     

兔眼蓝浆果花青素HPLC分析

蓝浆果又名越桔 ,是世界 4种新兴小果树之一。蓝浆果果皮色素鲜艳 ,可作为食品添加剂 ;由于其主要成分花青素有良好的生理活性 ,欧洲把花青素含量≥ 2 4%的色素提取物作为药用。其中欧洲越桔 (ＶａｃｃｉｎｉｕｍｍｙｒｔｉｌｌｕｓＬ .)色素的提取物 (Ｍｙｒｔｏｃｙａｎ)已被意大利、德国等国家的药典收载[1] 。色素作为蓝浆果重要成分 ,除可作为营养指标外 ,还可作为分类特征成分[2 ,3 ] 。不同的种以及不同的品种间 ,不仅花青素含量差异很大 ,而且色素成分的比例也不相同 ,因而可以用不同花青素比例区分染色体倍性不同的蓝浆果[2 ] 。花…     

Interaction of anthracycline antibiotics with biopolymers: 9. Comparative study of the interaction kinetics of daunomycin,adriamycin and iremycin with DNA

The interaction kinetics of the three anthracycline antibiotics, daunomycin, adriamycin and iremycin, with calf thymus DNA has been investigated using the temperature-jump technique. Experimental data obtained at high binding ratio have been fitted by a kinetic theory which, for the binding of large ligands to a linear polymer chain, takes into account both nearest-neighbour ligand interaction and the overlap of potential binding sites. The kinetics of such cooperative binding according to a single-step mechanism can be described completely by two independent microscopic parameters, namely one rate constant and a kinetic cooperativity parameter. Both these parameters have been determined for the three anthracyclcine antibiotics, making use of the known equilibrium binding parameters. The association rate constant in the singly contiguous case turns out to be almost the same for all three antibiotics ($\text{7 × 10}{}^6\text{to 8 × 10}{}^6\text{1 mol}{}^{\mathrm{?1}}\text{s}{}^{\mathrm{?1}}$), while the corresponding dissociation rate constant ranges from 3.5 s^?1 for adriamycin to 10 s^?1 for daunomycin and about 35 s^?1 for iremycin. The different equilibrium binding constants thus correspond to different mean attachment times of the antibiotics at the polymer chain, which positively correlate with the inhibitory action of these drugs on in vitro DNA synthesis. Nearest-neighbour interaction in the case of adriamycin-DNA binding kinetics implies that adriamycin molecules dissociate from an isolated binding site nine times more frequently than from a site between two adjacent ligands.     

Quantitative analysis of deoxynucleotide substitutions in the codon-anticodon helix

The role of 2' hydroxyl groups in the codon-anticodon helix was evaluated by introducing single deoxynucleotides into each of the six positions in the helix and measuring the affinity of tRNA to either the A site or the P site of Escherichia coli 70S ribosomes. In perfect agreement with the X-ray structure of the Thermus thermophilus 30S subunit, A site binding was weaker in five of the six positions but P site binding was unaffected. Since the addition of paromomycin restores A site binding, it appears that the deoxynucleotide substituted complexes are impaired in their ability to promote the ribosomal conformational change that accompanies tRNA binding.     

Measuring oxidative damage to DNA; HPLC and the comet assay compared

Depending on the analytical method employed estimates of background levels of base oxidation in human DNA vary over orders of magnitude. It is now realised that oxidation of guanine in vitro can result in serious overestimation of the nucleoside by HPLC (with electrochemical detection). We have modified procedures of isolation, hydrolysis and storage of DNA with the aim of eliminating this artefact. Vacuum- or freeze-drying, and dialysis, tend to encourage oxidation. We compare results obtained with HPLC and with the comet assay, which employs lesion-specific enzymes to introduce breaks in DNA at sites of oxidative damage. Although estimates of background levels of DNA oxidation using the comet assay are several-fold lower than the estimates by HPLC, both approaches have been used successfully to detect differences between human subjects or population groups that seem to relate to human disease and nutritional factors.