芥子酸及其衍生物对酪氨酸酶抑制作用的电化学研究

采用电化学方法研究了芥子酸、芥子酸甲酯及芥子碱对酪氨酸酶的抑制作用. 结果发现, 酪氨酸酶电极对其底物邻苯二酚有良好的电催化作用, 电流响应在底物1.0×10-7~6.0×10-5 mol/L的浓度范围内呈线性关系, 并具有较高的灵敏度(60.93 nA·L/μmol); 芥子酸及其衍生物都对酪氨酸酶的活性有抑制作用, 抑制能力大小的顺序为芥子酸>芥子酸甲酯>芥子碱. 通过对这3种物质的抑制参数的计算结果表明, 芥子碱是非竞争型抑制, 而芥子酸和芥子酸甲酯是混合型抑制. 这3种物质对酪氨酸酶可能的抑制机理一是抑制物与底物竞争酶的双铜活性中心; 二是抑制物具有抗氧化活性, 因而抑制酶对底物的催化反应.     

五种十字花科植物中芥子碱的有效提取和高效液相色谱定量分析

本文采用超声,乙醇回流、石油醚脱脂后醇提等提取方法,并通过正交试验,对五种十字花科植物种子白芥子、黄芥子、葶苈子、莱菔子和油菜籽中的芥子碱进行了有效提取,同时采用高效液相色谱法对各种方法得到的提取液进行了定量分析。结果表明:超声提取时间短、提取率高,五种种子中芥子碱的含量分别为5.80mg.g-1、5.13mg.g-1、2.62mg.g-1、2.98mg.g-1和3.31mg.g-1。     

表面解吸常压化学电离质谱原位检测萝卜中芥子碱及其含量衰减

采用表面解吸常压化学电离串联质谱（SDAPCI-MSn）技术,直接检测了白萝卜中的芥子碱,并考察了不同环境下芥子碱的衰减规律。 结果表明,常温下（25 ℃）白萝卜中的芥子碱浓度随时间迅速下降,在短时间衰减到一定程度后趋于平稳。 在低温下（≤4 ℃）,白萝卜中的芥子碱衰减速度则非常缓慢,有利于保持白萝卜中芥子碱水平。 萝卜鲜汁中的芥子碱在接触空气后的衰减速度是日常存储条件下的300多倍。 虽然在不同的条件下,芥子碱衰减的速度不同,但均符合一级反应的衰减规律。     

液相色谱-电喷雾离子阱质谱对芥子碱的测定方法

探讨了采用液相色谱-电喷雾串联质谱法检测小鼠前列腺中芥子碱硫氰酸盐的方法。流动相为V(乙腈)∶V(0.5%乙酸)=20∶80,色谱柱为ZorbaxXDB-C18(150 mm×4.6 mmi.d.,5μm),流速为0.6 mL/min。芥子碱硫氰酸盐的准分子离子和二级碎片离子分别为m/z 304和m/z 251,方法的检出限为0.7μg/L,线性范围为2.7~80.5μg/L,r为0.9934,相对标准偏差为7.5%~12.9%,样品的回收率为81.2%~102.5%。     

芥子碱与牛血清白蛋白的相互作用

利用荧光光谱法研究了新芥子碱与牛血清白蛋白(BSA)的相互作用,结果表明,新芥子碱对牛血清白蛋白的荧光有猝灭作用,且荧光光谱有较大的红移,其猝灭类型属于静态猝灭;根据Stern-Volmer荧光猝灭方程计算得到不同温度下的新芥子碱和BSA的结合常数和结合位点数;由实验计算得到该猝灭反应的热力学参数,表明新芥子碱与BSA之间相互作用以氢键和范德华力为主;根据能量转移理论求得新芥子碱与BSA的结合距离及能量转移率。     

高效液相色谱法同时测定减肥类保健食品中的6种成分

建立了一种同时测定减肥类保健食品中的荷叶碱,以及5种大黄蒽醌类化合物共6种成分的高效液相色谱测定方法。样品采用70%乙醇-水溶液超声提取30 min,离心后取上清液进样分析。菲罗门-Luna C_(18)柱(250 mm×4.6 mm,5μm)为分离柱,流动相为甲醇(A)和0.02%H_3PO_4溶液,梯度洗脱,254 nm作为检测波长。6种物质的线性相关系数在0.9992～0.9999范围内。各种目标化合物的方法日内精密度为0.79%～6.3%,日间精密度为0.90%～8.1%,加标回收率在62.5%～115.0%之间。该方法已成功应用于8种样品中6种目标物的测定。     

HPLC柱切换技术用于同时分析鱼腥草中3种黄酮类成分

利用柱切换技术解决了鱼腥草中难分离组分的分离和低含量组分的定量问题。以Synergi Fusion-RP柱(250 mm×4.6 mm i.d.,4μm)作为预柱,甲醇-0.05%磷酸溶液作流动相,以Acclaim120 C18柱(250mm×4.6 mm i.d.,5μm)作为分析柱,乙腈-0.05%磷酸溶液作流动相,对鱼腥草中的3种黄酮类成分进行分析。该方法在10.0～1 000.0 mg.L-1范围内线性关系良好,相关系数(r)不低于0.998,回收率为95%～99%,RSD值均小于3%。该方法操作简便、快速,可作为分析鱼腥草中黄酮类组分的有效手段。     

高效液相色谱法测定香连丸及组方药材中5种活性组分的含量

建立了香连丸及组方药材中药根碱、巴马汀、小檗碱、木香烃内酯和去氢木香内酯的含量测定方法．采用反相高效液相色谱,Hypersil ODS（5μm,4．6mm×250mm）色谱柱,流动相为乙腈：水（70：30,V：V）,流速1．0mL／min,柱温30℃,检测波长为210n／n测定木香烃内酯和去氢木香内酯的含量;采用高效液相胶束色谱,Kromasil ODS（5la,m,4．6mm×150mm）色谱柱,流动相为0．2mol／LNaH2P04水溶液：7．00mmol／L十二烷基硫酸钠：乙腈（35：35：30,V：V：V）,流速1．0mL／min,柱温30℃,检测波长为350nm测定药根碱、巴马汀、小檗碱的含量．结果显示5种活性成分在适当的线性范围内均具有良好的线性关系（r大于0．9993）,平均回收率在87．67％～102．37％之间,RSD小于3．13％;结果表明方法简便、灵敏、准确,重现性好．     

反相高效液相色谱法测定蒙成药活血六味胶囊中的大黄素

用反相高效液相色谱法测定蒙成药活血六味胶囊中的大黄素。采用KromasilC18色谱柱(4.6mm×250mm,5μm),流动相:甲醇:体积分数0.2%H3PO4溶液(85∶15),流速:1mL min;柱温25℃;检测波长:286nm。在0.042～0.925μg范围内,大黄素的量(x)与其峰面积(y)呈良好的线性关系(r=0 9991);回归方程为y=74.258x-8.714;加标回收率在97.98%～98.89%之间;RSD为0 47%。该方法可用于活血六味胶囊中大黄素的测定。     

离子色谱法直接测定聚合级乙二醇中痕量氯离子

分别采用KOH和Na_2CO_3/NaHCO_3淋洗液体系,建立了离子色谱直接测定聚合级乙二醇中痕量氯离子含量的两种方法。采用抽真空手动进样方式,分别以IonPac AS19(4 mm×250mm)为分析柱,IonPac AG19(4mm×50mm)为保护柱,5mmol·L~(-1) KOH溶液为淋洗液;以IonPac AS23(4mm×250mm)为分析柱,IonPac AG23(4mm×50mm)为保护柱,4.5mmol·L~(-1)Na_2CO_3-0.8mmol·L~(-1) NaHCO_3混合溶液为淋洗液进行分离,以电导检测器检测。两种方法中,氯离子的质量比在一定范围内与峰面积呈线性关系,检出限(10S/N)分别为0.002,0.006mg·kg~(-1),加标回收率分别为94.7%~100%,92.3%~99.8%,测定值的相对标准偏差(n=3)小于5.0%。两种方法测定聚合级乙二醇中痕量氯离子的结果具有一致性。     

Isolation and determination of p-hydroxybenzoylcholine in traditional Chinese medicine Semen sinapis Albae

A special component is isolated from Semen sinapis Albae (white mustard seed), a traditional Chinese medicine. According to the physical and chemical investigation and spectroscopic identification, this component can be known as p-hydroxybenzoylcholine bisulfate, a choline base. This component in the drug is also determined by RP-HPLC. A reversed-phase C₁₈ column is used to separate the p-hydroxybenzoylcholine with an eluent of methanol–0.05 mol/L monopotassium phosphate solution (30:70) (adjusted by phosphoric acid to pH 3.6) at the flow rate of 0.5 mL/min. Detection is carried out with a UV detector operated at 285 nm, and the column temperature is 25 °C. It reveals that there is 0.021% (w/w) of p-hydroxybenzoylcholine bisulfate in Semen sinapis Albae and 0.037% (w/w) in stir-baked Semen sinapis Albae.     

Quality evaluation of Semen Cassiae (Cassia obtusifolia L.) by using ultra-high performance liquid chromatography coupled with mass spectrometry

A sensitive and reliable ultra-high performance liquid chromatography-electrospray ionization-tandem mass spectrometry has been developed and partially validated to evaluate the quality of Semen Cassiae (Cassia obtusifolia L.) through simultaneous determination of 11 anthraquinones and two naphtha-γ-pyrone compounds. The analysis was achieved on a Poroshell 120 EC-C(18) column (100 mm × 2.1 mm, 2.7 μm; Agilent, Palo Alto, CA, USA) with gradient elution using a mobile phase that consisted of acetonitrile-water (30 mM ammonium acetate) at a flow rate of 0.4 mL/min. For quantitative analysis, all calibration curves showed perfect linear regression (r(2) > 0.99) within the testing range. This method was also validated with respect to precision and accuracy, and was successfully applied to quantify the 13 components in nine batches of Semen Cassiae samples from different areas. The performance of developed method was compared with that of conventional high-performance liquid chromatography method. The significant advantages of the former include high-speed chromatographic separation, four times faster than high-performance liquid chromatography with conventional columns, and great enhancement in sensitivity. This developed method provided a new basis for overall assessment on quality of Semen Cassiae.     

车前子多糖的测定方法研究

建立了一种准确测定车前子中多糖的方法。采用苯酚-硫酸法测定车前子中多糖量,以木糖作为标准对照物,检测波长480 nm。实验结果表明,车前子中多糖平均值为9.04%,平均加标回收率为98.2%,RSD=1.7%(n=6)。此测定方法适用于车前子多糖含量的测定,也可为其他戊糖含量高的多糖测定提供参考。     

高效液相色谱-电喷雾飞行时间质谱分析娑罗子中皂苷类成分

采用高效液相色谱/电喷雾飞行时间质谱联用技术(HPLC/ESI-TOF/MS),研究4种七叶皂苷的分子结构与裂解规律间的关系,并对娑罗子中的七叶皂苷类化合物进行鉴定。实验采用反相C18色谱柱,以乙腈-0.2%乙酸溶液为流动相,二元线性梯度洗脱,通过与电喷雾飞行时间质谱联用获得娑罗子中各皂苷成分的精确分子量和分子式;采用质谱碰撞诱导解离技术获得各化合物碎片裂解信息,结合文献对娑罗子中的14种皂苷类化合物进行了初步鉴定。研究表明,高效液相色谱-电喷雾飞行时间质谱联用技术是娑罗子中皂苷类化合物鉴别的有效工具。     

An LC–MS/MS method for simultaneous determination of hosenkoside A and hosenkoside K from Semen Impatientis in rat plasma and its application to a pharmacokinetic study

A rapid and sensitive liquid chromatography tandem mass spectrometry (LC–MS/MS) method was developed and validated for the simultaneous determination of two baccharane glycosides (hosenkoside A and hosenkoside K) of total saponins of Semen Impatientis in rat plasma using mogroside V as the internal standard (IS). The analytes were separated using a C₁₈ RP Agilent XDB column (1.8 μm, 50 × 2.1 mm i.d.) and detection of the compounds was done using a TSQ Quantum triple quadrupole mass spectrometer coupled with a negative electrospray ionization source under selection reaction monitoring mode. According to the US Food and Drug Administration guidelines, the established method was fully validated and the results were proved within acceptable limits. The lower limits of quantification of both analytes were 5 ng/mL. The validated method was successfully applied to a pharmacokinetic study of orally administered the total saponins of Semen Impatientis in rats.     

Chromatographic Fingerprint Analysis of Semen Ziziphi spinosae by HPLC-DAD Method

Abstract

Reliable, reproducible and valid fingerprint analysis methods using high-performance liquid chromatography-photodiode array detection (HPLC-DAD) for characteristic bioactive flavonoids and saponins of Semen Ziziphi spinosae (SZS) were developed and validated. HPLC separation of the chemical constituents of SZS was performed on an YMC-PACK ODS-A RP-18 column and detected at 270 and 204 nm for flavonoids and saponins, respectively. A mobile phase consisted of acetonitrile and 0.1% phosphoric acid aqueous solution was used with linear gradient elution. Using spinosin and jujuboside B as the reference markers of flavonoids and saponins respectively, 9 common fingerprint peaks of flavonoids and 10 common fingerprint peaks of saponins were specified based on the fingerprint analysis of 10 batches of SZS from different regions in China. The fingerprint analysis methods developed are reliable, reproducible and valid, and might be used as a more convenient approach for the species identification and quality monitoring and assessment of SZS.     

UHPLC-Quadrupole/Orbitrap MS同步检测十字花科植物中的游离氨基酸

采用超高效液相色谱-四极杆/静电场轨道阱高分辨质谱联用技术(UHPLC-Quadrupole/Orbitrap MS)结合柱前衍生法建立了可同时测定28种游离氨基酸的分析方法,并对十字花科植物中的游离氨基酸进行检测和分析。样品用超纯水提取后,经6-氨基喹啉基-N-羟基琥珀酰亚胺基甲酸酯(AQC)衍生,采用Waters BEH C18柱作为色谱柱,以pH 5.0乙酸铵缓冲溶液和80%乙腈水溶液作为流动相进行梯度洗脱。质谱检测器采用电喷雾离子源,在正离子模式下进行检测。实验结果表明,十字花科植物中含有25种以上游离氨基酸,其中包括人体必需的8种氨基酸。25种氨基酸在线性范围内相关性良好,平均加标回收率为80.5%~104.4%,相对标准偏差为0.6%~4.4%。不同氨基酸检测灵敏度不同,定量下限为0.01~1.45μmol/L。该方法杂质干扰小,分析速度快,灵敏度高,适用于植物样品中游离氨基酸的同步检测。     

Identification and determination of (+)-sesamin in Semen Cuscutae by capillary GC and GC-MS

(+)-Sesamin has been found to have pharmacological effect which can improve activity, prevent aging and has the effect of antihypertension 1-2. Figure 1 shows its chemical structure. (+)-Sesamin has been known to be abundant in sesame originally, but our previous study shows that (+)-sesamin also presents in a Chinese herbal medicine Semen Cuscutae3-4. Gas chromatography (GC) and gas chromatography - mass spectrometry (GC-MS) have been applied for the determination and identification of (+…     

超高效液相色谱-串联质谱法测定32种蔬菜中萝卜硫素

建立了超高效液相色谱-串联质谱(UHPLC-MS/MS)测定蔬菜中萝卜硫素的方法,并测定了32种常见蔬菜的萝卜硫素含量。取蔬菜冻干粉,利用内源黑芥子酶在p H 5的H3PO4缓冲液条件下酶解,酶解液经冷冻干燥后用乙酸乙酯提取,经减压浓缩后用50%乙腈-水(V/V)复溶。复溶液采用Shimpack XR-ODS II色谱柱,以0.1%(V/V)甲酸-水溶液和0.1%(V/V)甲酸-乙腈(95:5,V/V)为流动相进行梯度洗脱;采用电喷雾离子源(ESI),在正离子模式下进行多反应监测(MRM)扫描。结果表明,萝卜硫素在0.210~105 ng/mL范围内线性关系良好,检出限和定量限分别为52.5 pg/mL和210 pg/mL。经检测,西兰花中萝卜硫素的含量最高,其次为莲花白、花椰菜、紫甘蓝等十字花科植物。非十字花科蔬菜中,大葱的萝卜硫素含量最高。     

化学计量学用于决明子色谱指纹图谱峰纯度的鉴别

应用化学计量学方法鉴别色谱指纹图谱的峰纯度。对背景进行扣除后,用对照组分光谱构建正交投影矩阵对目标色谱峰的光谱进行投影,以目标色谱峰投影后的残余光谱与投影前的原始光谱的夹角余弦为判据鉴别目标色谱峰的峰纯度：用该方法对决明子药材色谱指纹图谱的峰纯度进行识别,鉴别出大黄素、大黄酚和大黄素甲醚三个纯色谱峰。此方法用于色谱指纹图谱峰纯度的鉴别,结果可靠。