Simultaneous determination of linarin,naringenin and formononetin in rat plasma by LC‐MS/MS and its application to a pharmacokinetic study after oral administration of Bushen Guchi Pill

A sensitive and reproducible liquid chromatography tandem mass spectrometry (LC‐MS/MS) method was developed and validated for the simultaneous determination of linarin, naringenin and formononetin in rat plasma after addition of sulfamethoxazole as the internal standard (IS). Separation was carried out on a Diamonsil C₁₈ column (150 × 4.6 mm, 5 µm) with liner gradient elution using methanol (A) and 0.5‰ formic acid aqueous solution (B). Detection was performed on a triple‐quadrupole linear ion trap mass spectrometer with the negative ion electrospray ionization in multiple‐reaction monitoring (MRM) mode. The MRM transitions were m/z 591.2 → 283.2, 271.0 → 150.9, 266.9 → 252.0 and 252.0 → 155.9 for linarin, naringenin, formononetin and IS, respectively. All analytes showed good linearity within the concentration range (r > 0.9973). The lower limits of quantitation of linarin, naringenin and formononetin were 0.64, 1.07 and 1.04 ng/mL, respectively. Intra‐day and inter‐day precisions of the investigated components exhibited an RSD within 9.96%, and the accuracy (relative error) ranged from ?11.25 to 9.38% at all quality control levels. The developed method was successfully applied to a pharmacokinetic study of linarin, naringenin and formononetin in rats after oral administration of Bushen Guchi Pill. Copyright © 2014 John Wiley & Sons, Ltd.     

Optimization of extraction of linarin from Flos chrysanthemi indici by response surface methodology and artificial neural network

The extraction of linarin from Flos chrysanthemi indici by ethanol was investigated. Two modeling techniques, response surface methodology and artificial neural network, were adopted to optimize the process parameters, such as, ethanol concentration, extraction period, extraction frequency, and solvent to material ratio. We showed that both methods provided good predictions, but artificial neural network provided a better and more accurate result. The optimum process parameters include, ethanol concentration of 74%, extraction period of 2 h, extraction three times, solvent to material ratio of 12 mL/g. The experiment yield of linarin was 90.5% that deviated less than 1.6% from that obtained by predicted result.     

A rapid and sensitive LC‐MS/MS method for the determination of linarin in small‐volume rat plasma and tissue samples and its application to pharmacokinetic and tissue distribution study

A rapid and sensitive LC‐MS/MS method was developed for the determination of linarin in small‐volume rat plasma and tissue sample. Sample preparation was employed by the combination of protein precipitation (PPT) and liquid–liquid extraction (LLE) to allow measurement over a 5‐order‐of‐magnitude concentration range. Fast chromatographic separation was achieved on a Hypersil Gold column (100 × 2.1 mm i.d., 5 µm). Mass spectrometric detection was achieved using a triple‐quadrupole mass spectrometer equipped with an electrospray ionization interface operating in positive ionization mode. Quantification was performed using selected reaction monitoring of precursor‐product ion transitions at m/z 593 → 285 for linarin and m/z 447 → 271 for baicalin (internal standard). The total run time was only 2.8 min per sample. The calibration curves were linear over the concentration range of 0.4–200 µg/mL for PPT and 0.001–1.0 µg/mL for LLE. A lower limit of quantification of 1.0 ng/mL was achieved using only 20 μL of plasma or tissue homogenate. The intra‐ and inter‐day precisions in all samples were ≤14.7%, while the accuracy was within ±5.2% of nominal values. The validated method has been successfully applied to pharmacokinetic and tissue distribution study of linarin. Copyright © 2015 John Wiley & Sons, Ltd.     

Separation of acteoside and linarin from Buddlejae Flos by high‐speed countercurrent chromatography and their anti‐inflammatory activities

Buddleja officinalis Maxim., a deciduous, flowering shrub, is used as a traditional Chinese medicine; the bioactivity of B. officinalis is primarily due to flavonoids and phenylethanoid glycosides. In the study, acteoside and linarin were successfully isolated from B. officinalis by high‐speed countercurrent chromatography with a two‐phase solvent system composed of ethyl acetate: n‐butanol: water (5:0.8:5, v/v/v). The purities of acteoside and linarin were determined to be 97.3 and 98.2%, respectively, using one‐step high‐speed countercurrent chromatography separation. The chemical structures of the two compounds were identified by electrospray ionization‐mass spectrometry and nuclear magnetic resonance. After separation, the anti‐inflammatory effects of the two compounds were evaluated using lipopolysaccharide‐induced human umbilical vein endothelial cells. Acteoside and linarin inhibited the expression of nitric oxide, tumor necrosis factor α and interleukin 1β, which demonstrated that acteoside and linarin possessed anti‐inflammatory activity.     

高效液相色谱法测定野菊花中蒙花苷的含量

建立高效液相色谱法测定野菊花中蒙花苷含量的方法。采用KromosilTM C18十八烷基硅烷键合硅胶色谱柱,甲醇-水-乙酸(体积比为55∶44.5∶0.5)为流动相,流速为0.8mL/min,柱温为室温,检测波长为334nm。蒙花苷含量在11.2~89.6μg/mL范围内,线性关系良好(r=0.9998),方法的相对标准偏差为0.51%(n=5),平均加标回收率为98.92%。     

Determination and pharmacokinetics of linarin in rat plasma after intramuscular administration of linarin solution and Yejuhua injection by HPLC

A simple and sensitive HPLC method was developed and validated for the determination of linarin in rat plasma. Plasma samples were carried out by protein precipitation with acetonitrile and separated on a Shim‐pack VP‐ODS analytical column (250 × 4.6 mm, 5 µm). The calibration curve was linear in the measured range of 20.8–4160 ng/mL and the lower limit of quantification was 20.8 ng/mL for linarin. The validated method was successfully applied to the pharmacokinetic study of linarin in rat plasma after intramuscular administration of monomeric compound and traditional Chinese medicinal preparation – Yejuhua injection. Copyright © 2014 John Wiley & Sons, Ltd.     

野菊花中蒙花苷的提取及其含量的测定

以乙醇为溶剂,采用溶剂回流提取方法结合微波、超声波辅助提取野菊花中的蒙花苷,用HPLC法测定。采用正交试验法研究了野菊花中蒙花苷提取和HPLC实验条件,并比较了采用不同的微波和超声波辅助提取方式对蒙花苷提取结果的影响。结果表明,溶剂回流提取最佳条件为:提取温度80℃,回流时间2.0 h,溶剂用量40 mL。应用于安徽等产地野菊花中蒙花苷的提取分析,结果显示,广东和广西产地药材含量明显更高;在相同的实验条件下采用微波辅助提取可使蒙花苷达到较高的提取率,特别是采用微波辐射药材后再进行溶剂回流提取,提取时间可缩短一半。