双波长薄层扫描法测定不同来源枸杞子中甜菜碱的含量

通过对枸杞子样品提取、脱色时间等前处理条件的优化,建立不同来源枸杞子中甜菜碱含量测定的双波长薄层扫描法(TLCS法)。使用快速溶剂萃取仪(ASE 350)用80%甲醇提取出枸杞子中的甜菜碱,经活性炭脱色、雷氏盐沉淀、丙酮溶解沉淀,采用改进的薄层扫描法在检测波长为530 nm,参比波长为625 nm条件下对枸杞子中的甜菜碱进行含量测定。得到清晰的薄层色谱斑点,无干扰;甜菜碱点样量在3.84~38.40μg范围内线性关系良好,r=0.9995;平均加样回收率为98.30%,RSD=2.55%(n=9)。该方法简便、准确,重现性好,适用于测定枸杞子中甜菜碱的含量测定,可为枸杞的质量控制提供依据。     

中压液相色谱法快速制备木犀草素-7-O-β-D-葡萄糖醛酸苷单体及鉴别

本文采用二元中压制备液相色谱系统,以装有反相C18(Chromatorex,MB 100-40/75)分离填料的两端具有锥形不锈钢接口的耐压玻璃柱(φ49 mm×H310 mm)作为制备色谱柱,流动相为甲醇(A)/含0.05%冰醋酸水溶液(B),梯度洗脱程序:0~20 min,10%(A);20~230 min,30%(A);230~270 min,60%(A);270~300 min,100%(A),流速:50 mL/min,检测波长254 nm,进样量:200 mL,从抱茎苦荬菜(苦碟子)总黄酮中快速、高效地分离得到木犀草素-7-O-β-D-葡萄糖醛酸苷(L7GU)单体。所得单体经UV、IR、TOF-MS、1H NMR、13C NMR方法进行了结构确证。经硅胶和聚酰胺薄层色谱检查,在365 nm紫外灯下均呈单一的黄绿色荧光斑点;HPLC-UV分析表明,在210、254、290、348 nm四个波长下,采用色谱峰面积归一化方法计算产品纯度均在98%以上。所得产品可直接作为对照品用于苦碟子药材及制剂的质量控制。     

用薄层色谱扫描法测定微生物酶反应液中的布洛芬

用薄层色谱扫描法(TLCS)测定由微生物酶立体选择性水解布洛芬消旋酯生成布洛芬的转化率。酶水解的反应液经酸化处理后用正己烷提取,在硅胶薄层板上用甲苯-乙酸乙酯-乙酸(70:30:1.5)上行展开,然后对布洛芬斑点进行原位吸光度扫描,测定波长212nm,以外标二点法面积校正定量。本法在测定布洛芬量2—6μg范围内,响应呈现良好的线性关系。测定水解反应液转化率的最大相对标准偏差小于4%,加量回收率为97.4—101.0%。     

薄层层析-紫外分光光度法测定十全大补胶囊中芍药苷含量

目的 建立薄层层析-紫外分光光度法测定十全大补胶囊中芍药苷含量的方法。方法 使用硅胶GF254薄层板,醋酸乙酯：甲酸：冰醋酸：水(30：2：2：4)为展开剂,在紫外光灯(254nm)下定位,230nm波长处检测。结果 点样量在25～125μg范围内呈现良好的线性关系,其回归方程为Y=0．004658C-0．01959,r=0．9994,平均回收率为99．20％,RSD=1．19％。结论 本法准确,适用于该药的质量控制。     

高效液相色谱法测定重组人干扰素α-2b注射液中乙二胺四乙酸二钠含量

目的:利用高效液相色谱(HPLC)法测定重组人干扰素α-2b注射液中EDTA二钠(乙二胺四乙酸二钠)的含量。方法:将EDTA二钠与氯化铁溶液于70℃水浴中反应20 min左右;色谱柱为SunFire C18(250 mm×4.6 mm,5μm,Waters),流动相为5%甲醇+95%0.64 g/L四丁基溴化铵和4.1 g/L三水合乙酸钠混合液,用冰乙酸调pH值至4.0,流速1 mL/min,检测波长254 nm。结果:该测定方法线性范围为0.025~0.5 g/L,线性关系良好(r=0.9997),加样回收率为98.27%(n=9,RSD=2.55%)。结论:本方法准确、快速、可靠,可用于重组人干扰素α-2b注射液中EDTA二钠含量的测定。     

GABA茶中γ-氨基丁酸的TLC测定及提纯研究

本文对GABA茶中有效成分γ-氨基丁酸的薄层扫描(TLC)检测以及提取、分离、纯化进行了研究,结果表明:正丁醇?醋酸?水体积比为4?1?1展开剂分离效果较好,R f值为0.46。采用双波长扫描法检测,扫描波长分别为λS=515nm,λR=680 nm,检测线性范围:0.5μL~15μL,样品平均回收率为98.75%。采用水提取法比乙醇提取法γ-氨基丁酸含量提高20%左右,732阳离子树脂对γ-氨基丁酸的静态最大吸附量为32.9 mg.g-1,1 h内其吸附速度较快,达吸附量的70%。样液pH值、流速等因子对树脂的吸附效率有影响,当pH值为3.0,流速3 m l.m in-1时,树脂的吸附量达到最大值。采用柠檬酸缓冲液和NH3.H2O进行洗脱,当pH为8.0~9.0时,γ-氨基丁酸洗脱率达94.68%。     

薄层荧光扫描法测定花生茎中白藜芦醇的含量

本文采用薄层荧光扫描法测定花生茎中白藜芦醇含量,以氯仿-乙酸乙酯-甲酸(8∶2∶0.35)为展开剂,狭缝尺寸为3 mm×0.45 mm,在335 nm处进行扫描测定。结果表明:白藜芦醇在46.4~104.4 ng范围内线性关系良好,回归方程为:Y=7.446X 2890.328相关系数R为0.9970。该法简便,快速,精密度高,平均回收率为103.46%,相对标准偏差为0.66%(n=3)。     

HPLC法测定芦笋茎秆中芦丁、槲皮素及白藜芦醇含量

为了建立高效液相色谱法对芦笋茎秆中芦丁、槲皮素和白藜芦醇含量的测定方法。采用不同方法提取芦笋茎秆中的芦丁、槲皮素和白藜芦醇,得出甲醇法提取芦丁、甲醇-HCl法提取槲皮素以及乙醇法提取白藜芦醇得率最高;确定了高效液相色谱法对3种物质的最佳色谱条件为流动相:芦丁为0.2 mol/L乙酸钠-甲醇(Me-OH∶H2O=35∶65)溶液(用磷酸调p H 2.80)、槲皮素为无水甲醇-0.4%磷酸溶液(55∶45,V/V),等梯度洗脱,白藜芦醇为水和甲醇,二元线性梯度洗脱;检测波长分别为:254 nm、360 nm和306 nm;流速:0.8 m L/min、1.0 m L/min、0.8 m L/min。通过该方法测得芦丁、槲皮素及白藜芦醇的平均回收率分别为:98%、97%、98%。     

UPLC同时检测姜黄素-胡椒碱纳米混合胶束中姜黄素和胡椒碱的含量

文章采用了同时测定姜黄素-胡椒碱纳米混合胶束中姜黄素和胡椒碱含量的超高效液相色谱(UPLC)分析方法。超高效液相色谱法,Waters BEH C₁₈(2.1×100 mm,1.7μm)色谱柱;流动相为乙腈;检测波长为430 nm(姜黄素)、343 nm(胡椒碱);流速为0.15 m L·min^-1;进样量为1μL,柱温为30℃。姜黄素和胡椒碱的线性范围分别为12.41～198.6μg·m L^-1(r=0.999 9)和0.62～9.9μg·m L^-1(r=0.999 9);平均回收率分别为99.77%和99.82%,S_RSD分别为0.10%和0.17%。该方法分析速度快、灵敏度高、准确性高、重复性好,结果准确、可靠,可用于姜黄素-胡椒碱纳米混合胶束中姜黄素和胡椒碱含量的测定。     

类肌肽4(5)-丙氨酰胺-5(4)-羧酸咪唑的酶促合成及表征

肌肽(β-Ala-L-His)是一种高效抗氧化剂,广泛应用于生物、化工、医药等领域。应用微水相酶促合成类肌肽,效率高价格低,且具有相似性质,开发前景广阔。本研究以L-丙氨酸和4,5-二羧酸咪唑制备类肌肽4(5)-丙氨酰胺-5(4)-羧酸咪唑,正交实验下的最佳合成条件为:四氢呋喃:pH8磷酸缓冲溶液=10:1.6(V/V),L-丙氨酸:4,5-二羧酸咪唑=1:3(m/m),α-胰凝乳蛋白酶:底物=1:200(m/m),35oC下磁力搅拌1.5h。硅胶G60薄层色谱(TLC)分离反应产物,Rf=0.81处出现新斑点;刮下该点纯化后进行紫外扫描,高效液相色谱(HPLC)和核磁共振,紫外光谱253nm处吸收明显增强,310nm处出现新吸收峰;253nm、310nm、330nm高效液相色谱保留时间均为4.0min;13C核磁共振显示8组碳原子。结合胰凝乳蛋白酶的催化机理,得出产物结构为4(5)-丙氨酰胺-5(4)-羧酸咪唑。     

The solvent-initiated photochemistry of tris(N,N-diethyldithiocarbamato)iron(III)

The photolysis of [Fe(Et₂dtc)₃], Et₂dtc = diethyldithiocarbamate to yield [Fe(Et₂dtc)₂Cl] proceeds under 313 nm irradiation through a metal complex excited state, as expected. Under 254 nm irradiation, however, the dominant pathway is through a solvent-initiated reaction in which radicals formed after absorption of light by CHCl₃ react thermally with [Fe(Et₂dtc)₃]. The initial rate varies linearly with the light intensity at 313 nm, but at 254 nm varies with the square root of the intensity.     

不同功率的激光刺激对小鼠C2C12成肌细胞耗氧率水平的影响及机制

目的：探讨不同功率的低强度650 nm激光刺激对C₂C₁₂成肌细胞耗氧率水平和相关蛋白的影响及其机制。方法：以体外培养的C₂C₁₂小鼠成肌细胞作为实验对象,以4×10⁵个/孔接种于牵张6孔板中,采用输出功率5 mW,波长650 nm的二极管激光进行单次刺激,激光照射剂量分别0 J/cm²（0 min）、0.4 J/cm²（12.8 min）、0.8 J/cm²（25.6 min）。实验结束后,采用耗氧率试剂盒（Luxcel Biosciences）检测细胞耗氧率;提取细胞总蛋白,采用Western blot技术检测成肌调节因子（MyoD）、过氧化物酶体增殖活化受体γ共激活因子1α（PGC-1α）、雷帕霉素靶蛋白和磷酸化蛋白（p-mTOR/mTOR）表达。结果：与对照组相比,低剂量组细胞氧化耗氧率结果、MyoD、PGC-1α蛋白表达显著增加（P<0.05）,高剂量组MyoD、PGC-1α蛋白表达显著增加（P<0.05）,p-mTOR/mTOR蛋白显著降低（P<0.05）。结论：较低剂量（0.4 J/cm²）的650 nm低强度激光增强了细胞氧化功能水平,并对细胞分化相关蛋白有一定影响。其机制可能与适宜的激光刺激影响PGC-1α蛋白的表达,进而影响线粒体氧化呼吸有关。     

HPLC法测定头孢克肟的含量

采用高效液相色谱法测定头孢克肟的含量 ,HPL C法 C1 8为填充柱 (6 .0× 15 0 mm ) ,以氢氧化四丁铵 -乙腈 (34 0 :16 0 )为流动相 ;检测波长为 2 5 4nm。结果 :线性范围为 0 .144 mg/ ml～ 0 .2 80 mg/ ml(r=0 .9999) ,平均回收率为 99.80 %,RSD=0 .2 0 %(n=3)。本法具有柱效高、经济等优点 ,优于 USP法。     

Determination of pyronaridine in blood plasma by high-performance liquid chromatography for application in clinical pharmacological studies

A method is described for the determination of pyronaridine in plasma using high-performance liquid chromatography with fluorescence detection. The method involves liquid-liquid extraction with phosphate buffer (pH 6.0, 0.05 M) and diethyl ether-hexane (70:30%, v/v) and chromatographic separation on a C₁₈ column (Nucleosil, 250 × 4.6 mm I.D., 5 μm particle size) with acetonitrile-0.05 M phosphate buffer pH 6.0 (60:40%, v/v) as the mobile phase (1 ml/min) and detection by fluorescence (λ_ex = 267 nm, λ_em = 443 nm). The detector response is linear up to 1000 ng and the overall recoveries pyronaridine and quinine were 90.0 and 60.3%, respectively. The assay procedure was adequately sensitive to measure 10 ng/ml pyronaridine in plasma samples with acceptable precision (< 15% C.V.). The method was found to be suitable for use in clinical pharmacological studies.     

濒危植物裂叶沙参种群生殖力表的研究

本文分别以当年产种子数量和一年生幼苗数量为基础,编制了裂叶沙参种群(总和)和海拔2300-2400m, 2700-2900m, 2900-3100m, 3100-3400m 4个不同海拔区域种群的生殖力表,分析了不同种群两种生殖表的种群内禀增长率(r_m),周限增殖率(λ),净增长率(R₀),毛增长率(G)等动态参数与种群动态的关系;比较了两种生殖力表的特点和利弊;讨论了裂叶沙参种群生殖生态学特性和种群发展趋势及其与环境因素的关系。以种子数量为基础编制的生殖力表的各种群动态参数表明,裂叶沙参具有较强的产生种子的能力,特别是在生境条件较好的海拔2700-3100m区域,种群个体结实量可达到很高的水平。以一年生幼苗数量为基础编制的生殖力表表明,裂叶沙参种群从整体上呈衰退趋势。但不同种群间存在差异:在海拔2300-2400m,水份条件较好的特殊生境和海拔2900-3100m的种群呈稳定特征;而海拔2700-2900m,3100-3400m的种群呈缓慢衰退特征。以种子数量为基础编制的生殖力表可以反映裂叶沙参种群产生种子的能力和生殖生态学特征;而以一年生幼苗数量为基础编制的生殖力表包含了种子库的生态学过程,能较好的反映种群动态特征。在实践中,两种生殖力表应配合使用,才能全面刻划种群生殖生态学和种群动态特征。     

蓝藻红色荧光蛋白All1280 GAF2在E.coli BL21(DE3)中的表达及其突变体构建

采用PCR技术从鱼腥藻（Anabaena sp.）PCC 7120中扩增获得红色荧光蛋白基因all1280 gaf2,并利用BamHⅠ和SalⅠ酶切位点,将该基因插入到pET-30a（+）中,构建表达载体pET-all1280 gaf2。将该表达载体与藻胆色素生物合成质粒pACYC-ho1-pcyA同时转化到大肠杆菌E.coli BL21（DE3）,表达后获得大肠杆菌色素细胞。结果显示,该色素细胞在荧光显微镜下具有红色荧光,且在15E/15Z态之间具有可逆光效应。进一步以pET-all1280 gaf2为模板,通过定点突变技术在all1280 gaf2基因中引入C53A突变,获得了突变体All1280 GAF2（C53A）。将All1280 GAF2（C53A）与藻胆色素在E.coli BL21（DE3）中共表达,获得了比野生型红色荧光更强的大肠杆菌色素细胞。研究结果表明,与野生型相比,All1280 GAF2（C53A）具有较高的摩尔消光系数和荧光量子产率,红色荧光更强。     

Determination of nadoxolol in human plasma using reversed-phase high-performance liquid chromatography

A rapid, simple and accurate HPLC method is presented for the determination of nadoxolol in human plasma. Nadoxolol from plasma was successfully purified using an Adsorbex column. The samples were chromatographed on a LiChrosorb RP-18 (10 μm) column with methanol—acetonitrile—phosphate buffer (pH 3.3) (70:20:10) as the mobile phase. Detection was carried out at 254 nm. The method was tested for linearity (from 5 to 25 μg/ml), recovery (85%) and precision (C.V. = 4.5%).     

Determination of clozapine and its major metabolites in human plasma and red blood cells by high-performance liquid chromatography with ultraviolet absorbance detection

An isocratic high-performance liquid chromatographic (HPLC) method with UV absorbance detection is described for the quantification of clozapine (8-chloro-11-(4′-methyl)piperazino-5H-dibenzo[b,e]-1,4-diazepine) and its two major metabolites in plasma and red blood cells (RBCs). The method involves sample clean-up by liquid-liquid extraction with ethyl acetate. The organic phase was back-extracted with 0.1 M hydrochloric acid. Loxapine served as the internal standard. The analytes were separated by HPLC on a Kromasil Ultrabas C₁₈ analytical column (5 μm particle size; 250×4.6 mm I.D.) using acetonitrile-phosphate buffer pH 7.0 (48:52, v/v) as eluent and were measured by UV absorbance detection at 254 nm. The limits of quantification were 20 ng/ml for clozapine and N-desmethylclozapine and 30 ng/ml for clozapine N-oxide. Recovery from plasma or RBCs proved to be higher than 62%. Precision, expressed as % C.V., was in the range 0.6–15%. Accuracy ranged from 96 to 105%. The method's ability to quantify clozapine and two major metabolites simultaneously with precision, accuracy and sensitivity makes it useful in therapeutic drug monitoring.     

超声提取-高效液相色谱法测定甘草中甘草酸含量

确定了制备甘草酸分析样品的超声波提取条件, 0.3%稀氨水为溶剂,液固比50:1,提取时间5 h;确定了高效液相色谱法检测甘草酸含量的条件为ODS色谱柱(4.6mm×25 cm, 5 μm),检测波长254 nm,检测温度为室温,流动相CH3OH/3% HOA c(V/V)为75/25,流速1mL/m in,进样量10 μL,平均加样回收率100.20%,相对标准偏差为1.77%。结果表明超声提取-高效液相色谱法是一种准确度高,速度快的测定甘草中甘草酸含量的检测方法。     

Revised procedures for the certification of carmine (C.I. 75470, Natural red 4) as a biological stain

Carmine is one of the original dyes certified by the Biological Stain Commission (BSC). Until now it has lacked both an assay procedure for dye content and a means to positively identify the dye. The methods for testing carmine in the laboratory of the BSC have been revised to include spectrophotometric examination at pH 12.5-12.6 to determine that the dye is carmine (λ_max=530-335 nm). The maximum absorbance of a solution containing 100 mg of dye per liter of water, adjusted to pH 12.5-12.6, which provides a relative measure of dye content, should lie in the range 1.2 to 1.8. If the dye is not carmine, spectrophotometry at pH 1.9-2.1 shows whether it is carminic acid (λ_max=490-500 nm) or 4-aminocarminic acid (λ_max=525-530 nm). The latter two dyes, which are also called carmine when sold as food colorants, have physical properties different from those of true carmine. The functional tests for carmine as a biological stain are Orth's lithium-carmine method for nuclei, Southgate's mucicarmine method for mucus, and Best's carmine method for glycogen.