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Determination of neuroprotective oxysterols in Calculus bovis,human gallstones,and traditional Chinese medicine preparations by liquid chromatography with mass spectrometry
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Yalong Wang Han Jiang Huizhi Huang Yanqi Xie Yunshi Zhao Xiuhua You Lipeng Tang Youqiong Wang Wei Yin Pengxin Qiu Guangmei Yan Haiyan Hu 《Journal of separation science》2015,38(5):796-803
So far, the components responsible for the neuroprotective effects of Calculus bovis are unclear. Cholesterol, one of the major components in Calculus bovis, is easily oxidized into oxysterols, which possess direct or indirect neuroprotective effects proved by our and others’ previous studies. Therefore, a liquid chromatography with mass spectrometry method coupled with ultrasonic extraction and solid‐phase extraction was developed for the determination of neuroprotective oxysterols in Calculus bovis, human gallstones, and traditional Chinese medicine preparations. Chromatographic separation was achieved on a C18 column with isocratic elution at a flow rate of 1 mL/min. The established method showed good linearity (R2 > 0.998), sensitivity with low limits of detection (0.06–0.39 μg/g), acceptable precisions (relative standard deviations ≤ 7.4%), stability (relative standard deviations ≤ 5.9%), and satisfactory accuracy (92.4–102.9%) for all analytes identified by different retention times, which could be applied for the determination of oxysterols. Five kinds of oxysterols proved to function as neuroprotectants were detected at different concentrations. Among them, 7β‐hydroxycholesterol and cholestane‐3β,5α,6β‐triol were rather abundant in the samples. It could be concluded that the potential neuroprotective components in Calculus bovis may be these oxysterols. 相似文献
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采用噬菌体生物扩增法对本实验室分离鉴定的25株奶牛结核分支杆菌进行药敏分析,检测出14株耐链霉素、利福平、异烟肼菌株.用PCR扩增耐药株的rpsL基因片段(370bp)、rpoB基因片段(213bp)和KatG基因片段(458bp),并对目的片段进行测序分析,其中5株耐链霉素菌株的rpsL基因在43位点发生突变,均由赖氨酸密码子(AAG)突变为精氨酸密码子(AGG);5株利福平耐药株的rpoB基因在531位点、526位点、5¨位点发生突变,其中有3株分离株的rpoB基因在531位点发生点突变,1株分离株的rpoB基因在526位点发生突变,1株分离株的rpoB基因在531位点和511位点发生了较为少见的联合突变;4株异烟肼耐药菌株,其中2株在315位点发生碱基突变,2株在463位点发生碱基突变. 相似文献
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Zang QC Wang JB Kong WJ Jin C Ma ZJ Chen J Gong QF Xiao XH 《Journal of separation science》2011,34(23):3330-3338
The fingerprints of artificial Calculus bovis extracts from different solvents were established by ultra-performance liquid chromatography (UPLC) and the anti-bacterial activities of artificial C. bovis extracts on Staphylococcus aureus (S. aureus) growth were studied by microcalorimetry. The UPLC fingerprints were evaluated using hierarchical clustering analysis. Some quantitative parameters obtained from the thermogenic curves of S. aureus growth affected by artificial C. bovis extracts were analyzed using principal component analysis. The spectrum-effect relationships between UPLC fingerprints and anti-bacterial activities were investigated using multi-linear regression analysis. The results showed that peak 1 (taurocholate sodium), peak 3 (unknown compound), peak 4 (cholic acid), and peak 6 (chenodeoxycholic acid) are more significant than the other peaks with the standard parameter estimate 0.453, -0.166, 0.749, 0.025, respectively. So, compounds cholic acid, taurocholate sodium, and chenodeoxycholic acid might be the major anti-bacterial components in artificial C. bovis. Altogether, this work provides a general model of the combination of UPLC chromatography and anti-bacterial effect to study the spectrum-effect relationships of artificial C. bovis extracts, which can be used to discover the main anti-bacterial components in artificial C. bovis or other Chinese herbal medicines with anti-bacterial effects. 相似文献
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应用分子遗传学方法,以光敏生物素标记的DNA探讨针进行分子杂交等手段克隆了牛摩拉氏菌溶血素结构基因,并在大肠杆菌中得到表达,其重组子定名为MR9,分子量为6.45Kb,外源片段分子量为3.8Kb? 相似文献
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Simultaneous quantification of the major bile acids in Artificial Calculus bovis by high‐performance liquid chromatography with precolumn derivatization and its application in quality control
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Yan Shi Jing Xiong Dongmei Sun Wei Liu Feng Wei Shuangcheng Ma Ruichao Lin 《Journal of separation science》2015,38(16):2753-2762
An accurate and sensitive high‐performance liquid chromatography method coupled with ultralviolet detection and precolumn derivatization was developed for the simultaneous quantification of the major bile acids in Artificial Calculus bovis, including cholic acid, hyodeoxycholic acid, chenodeoxycholic acid, and deoxycholic acid. The extraction, derivatization, chromatographic separation, and detection parameters were fully optimized. The samples were extracted with methanol by ultrasonic extraction. Then, 2‐bromine‐4’‐nitroacetophenone and 18‐crown ether‐6 were used for derivatization. The chromatographic separation was performed on an Agilent SB‐C18 column (250 × 4.6 mm id, 5 μm) at a column temperature of 30°C and liquid flow rate of 1.0 mL/min using water and methanol as the mobile phase with a gradient elution. The detection wavelength was 263 nm. The method was extensively validated by evaluating the linearity (r2 ≥ 0.9980), recovery (94.24–98.91%), limits of detection (0.25–0.31 ng) and limits of quantification (0.83–1.02 ng). Seventeen samples were analyzed using the developed and validated method. Then, the amounts of bile acids were analyzed by hierarchical agglomerative clustering analysis and principal component analysis. The results of the chemometric analysis showed that the contents of these compounds reflect the intrinsic quality of artificial Calculus bovis, and two compounds (hyodeoxycholic acid and chenodeoxycholic acid) were the most important markers for quality evaluating. 相似文献
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建立了同时测定人工牛黄中石油醚(60~90 ℃)、丙酮、乙酸乙酯、甲醇、二氯甲烷、乙醇、乙酸丁酯7种残留溶剂的顶空气相色谱分析方法。以Agilent DB-WAX毛细管色谱柱为分离柱,氢火焰离子化检测器检测,内标法定量,并考察了顶空平衡温度、加压时间、平衡时间等对残留溶剂测定的影响。在优化的条件下,7种残留溶剂在选择的浓度范围内线性关系良好,相关系数(r)均不小于0.9993;在高、中、低3个加标水平下,平均回收率为94.7%~105.2%,相对标准偏差(RSD)均不大于3.5%。方法的检出限(LOD)为0.43~5.23 mg/L,定量限(LOQ)为1.25~16.67 mg/L。该方法操作简单、准确灵敏、高效快捷,适用于人工牛黄中7种残留溶剂的同时检测。 相似文献
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