Chemical composition and biological activities of essential oil from Filifolium sibiricum (L.) Kitam

The essential oil from Filifolium sibiricum (L.) Kitam were extracted using hydrodistillation and GC-MS was used to analyse the essential oil. The main components were espatulenol (8.55%), geranyl acetate (8.03%), caryophyllene oxide (5.47%), calamenene (4.79%), geraniol (4.28%), calamenene (4.53%), geraniol (4.06%), cedrene epoxide (3.23%), myrtenol (3.18%), transgeranylgeranio (3.13%), etc. The essential oil showed intensive inhibitory effects against MCF-7 with IC₅₀ level of 0.78 mg/mL, HepG-2 with IC₅₀ level of 0.44 mg/mL, SKOV-3 with IC₅₀ level of 0.27 mg/mL, BGC-823 with IC₅₀ level of 0.34 mg/mL. In the antibacterial test, the essential oil showed the significant antibacterial activities. The MIC and MBC values were 5.20 and 5.20 mg/mL against Staphylococcus aureus.     

二乙二醇十八烷基醚单甲基丙烯酸酯及其聚合物的制备和表征简

以二乙二醇十八烷基醚和甲基丙烯酰氯为原料,采用醇钠-酰氯法合成了二乙二醇十八烷基醚单甲基丙烯酸酯(DEGOEMA),并利用自由基聚合得到聚(二乙二醇十八烷基醚单甲基丙烯酸酯)(PDEGOEMA). 采用凝胶渗透色谱(GPC)分析测试了PDEGOEMA的分子量和分子量分布. 通过傅里叶变换红外光谱(FTIR)、核磁共振氢谱(1H NMR)、差示扫描量热(DSC)、热重(TG)和X射线衍射(XRD)对DEGOEMA和PDEGOEMA的结构、相变行为、热稳定性和晶体结构进行了研究. 结果表明,这种新型单体及其聚合物是一种具有稳定的结构、良好的结晶性能、高相变焓及良好热稳定性的相变材料. PDEGOEMA的起始吸热温度为41 ℃,起始放热温度为36 ℃,热焓为73 J/g,在314 ℃以下热稳定性良好,可用于加工或使用温度较高的环境.     

A rapid ultra-performance liquid chromatography-electrospray ionization tandem mass spectrometric method for the qualitative and quantitative analysis of the constituents of the flower of Trollius ledibouri Reichb

A rapid ultra-performance liquid chromatography-electrospray ionization tandem mass spectrometric (UPLC–ESI-MS/MS) method was developed for the qualitative and quantitative determination of the constituents of the flower of Trollius ledibouri Reichb. The analysis was performed on an AcQuity UPLC™ BEH C₁₈ column using gradient elution with a mobile phase of 0.1% acetic acid and acetonitrile over 20 min. A tandem quadrupole spectrometer operating in either full scan mode or in MS/MS mode for multiple reaction monitoring (MRM) was used for the qualitative and quantitative analysis of the constituents, respectively. According to the mass spectrometric fragmentation mechanism and UPLC–ESI-MS/MS data, the chemical structures of 15 constituents of the flower of T. ledibouri Reichb. were identified on-line without time-consuming isolation and four of them, 2″-O-β-l-galactopyranosylorientin, 2″-O-β-arabinopyranosylorientin, orientin and vitexin, were quantified. The limits of quantification of these four flavonoids were 540, 321, 515 and 220 μg g⁻¹ plant material, respectively. Four commercial samples from different sources were analyzed. The UPLC–ESI-MS/MS method for analyzing the constituents can be used to evaluate the quality of the flower of T. ledibouri Reichb.     

三线摆摆线质量对转动惯量精确测量的影响

三线摆法是测量转动惯量的常用方法, 理论上通常都是把摆线作理想处理(即摆线质量趋于0), 但在工程测量中, 被测工件往往较重, 摆线不再是轻质细线, 摆线质量势必会对空载悬盘的转动惯量测量产生影响. 本文应用哈密顿原理和变量替换, 导出三线摆摆线的变张力弦振动方程, 通过对摆线与悬盘连接点(x=0)的运动状态讨论, 推得摆线质量不能忽略情形下的对称式三线摆的转动惯量计算式, 并借助于MATLAB 软件快速便利地进行计算.     

The application rule of simple symmetrical wave signal magneto-optical modulation in spatial azimuth measurement

The purpose of the study is to summarize the application rule of sine wave and other simple symmetrical wave signal magneto-optical modulation in azimuth measurement, and acquire the limit on modulation signal when establishing azimuth measurement model. Firstly, we analyze the principle of traditional azimuth measurement system based on sine wave signal magneto-optical modulation, and establish the error free measurement model based on trigonometric function, after that we present the measurement models based on mixed signal with tangent, cosine and sine function, respectively. Secondly, we discuss the application feasibility of rectangle wave, triangle wave and sawtooth wave signal magneto-optical modulation in azimuth measurement respectively, and establish the azimuth measurement models based on rectangle wave and triangle wave signal modulation respectively, and analyze the reason why the sawtooth wave signal modulation cannot be applied in the azimuth measurement. Finally, we summarize the four simple signal magneto-optical modulation and acquire the requirements on modulation signal when establishing the azimuth measurement model based on simple wave single magneto-optical modulation. The study has an important guiding significance on the application of simple symmetrical wave magneto-optical modulation in azimuth measurement.     

The application rule of half-wave signal magneto-optical modulation in spatial azimuth measurement

The purpose of this study is to summarize the application rule of half-wave signal magneto-optical modulation in azimuth measurement, and obtain the limit on modulation signal when establishing the azimuth measurement model. After analysis on the azimuth measurement system principle, the model of modulated signal are present according to Malous law, the application feasibility of the four half-wave signal magneto-optical modulation in azimuth measurement are discussed respectively, the azimuth measurement models based on mixed signal are present, and the reason why the AC signal cannot be used to establish the azimuth measurement model is analyzed.     

Equal ratio of graphite carbon to activated charcoal for enrichment of N-glycopeptides prior to matrix-assisted laser desorption/ionization time-of-flight mass spectrometric identification

Site-specific glycoprofiling of N-glycoproteins is based on the enrichment of glycopeptides. In this study, we develop a simple and economical ZipTip microcolumn packed with a 1:1 ratio of graphite carbon to activated charcoal (w/w) (termed as GA-ZipTip microcolumn) to efficiently isolate and enrich N-glycopeptides from digested mixtures of individual glycoproteins and also investigate the ratio effect on the isolation and enrichment of glycopeptides. The experimental data showed that the microcolumn could efficiently and reproducibly isolate N-glycopeptides from enzymatic mixtures of ovalbumin, fetuin, haptoglobin and human plasma. The results obtained here demonstrate that the GA-ZipTip microcolumn is a powerful tool to enrich unbiasedly N-glycopeptides, which will be benefit for glycoproteomics and complex biological samples.     

HPLC法分析生物样品的前处理技术

介绍HPCL法分析生物样品的前处理技术。     

环丙烷衍生物在CD3OD离子体系中的H/D交换反应

研究了环丙烷衍生物在CD     

中药质量控制的研究策略和色谱技术

综述了色谱技术作为现代高效分离分析技术在中药药效物质基础研究和中药质量控制中的重要作用。提出中药药效物质组学研究策略,以实现中药药效物质基础与作用机理研究的一体化,进而从深层次揭示和全面控制中药的内在质量。论述结果表明,现代色谱及其联用技术是中药质量研究的重要技术平台之一。