Absolute bioavailability,dose proportionality,and tissue distribution of rotundic acid in rats based on validated LC-QqQ-MS/MS method

Rotundic acid(RA),an ursane-type pentacyclic triterpene acid isolated from the dried barks of Ilex rotunda Thunb.(Aquifoliaceae),possesses diverse bioactivities.To further study its pharmacokinetics,a simple and sensitive liquid chromatography with triple quadrupole mass spectrometry(LC-QqQ-MS/MS)method was developed and validated to quantify RA concentration in rat plasma and tissue using etofesalamide as an internal standard(IS).Plasma and tissue samples were subjected to one-step protein precipitation.Chromatographic separation was achieved on a ZORBAX Eclipse XDB-C_(18) column(4.6mm×50mm,5μm)under gradient conditions with eluents of methanol:acetonitrile(1:1,V/V)and 5mM ammonium formate:methanol(9:1,V/V)at 0.5mL/min.Multiple reaction monitoring transitions were performed at m/z 487.30→437.30 for RA and m/z 256.10→227.10 for IS in the negative mode.The developed LC-QqQ-MS/MS method exhibited good linearity(2-500 ng/mL)and was fully validated in accordance with U.S.Food and Drug Administration bioanalytical guidelines.Dose proportionality and bioavailability in rats were determined by comparing pharmacokinetic data after single oral(10,20,and 40mg/kg)and intravenous(10mg/kg)administration of RA.Tissue distribution was studied following oral administration at 20mg/kg.The results showed that the absolute bioavailability of RA after administration at different doses ranged from 16.1%to 19.4%.RA showed good dose proportionality over a dose range of 10-40 mg/kg.RA was rapidly absorbed in a dose-dependent manner and highly distributed in the liver.In conclusion,this study is the first to systematically elucidate the absorption and distribution characteristics of RA in rats,which can provide additional information for further development and evaluation of RA in drug metabolism and pharmacokinetic studies.

LC-QQQ-MS/MS分析苯磺酸氨氯地平中痕量苯磺酸酯类基因毒性杂质

目的建立LC-QQQ-MS/MS分析测定苯磺酸氨氯地平中痕量苯磺酸酯类基因毒性杂质苯磺酸甲酯、苯磺酸乙酯、苯磺酸丙酯和苯磺酸异丙酯的检测方法。方法采用AgilentZorbaxSB-C18(3.0 mm×100 mm,1.8mm)色谱柱,以水(含5 mmol·L-1甲酸铵和0.1%甲酸)和甲醇(含5 mmol·L-1甲酸铵和0.1%甲酸)为流动相,梯度洗脱,流速0.4 mL·min-1,电喷雾离子化(ESI),正离子模式下MRM采集。结果苯磺酸甲酯定量下限为20ng·mL-1,苯磺酸乙酯、苯磺酸丙酯和苯磺酸异丙酯定量下限为1 ng·mL-1;方法精密度良好,保留时间和峰面积RSD均<5%(n=10);苯磺酸甲酯在20~1000 ng·mL-1,苯磺酸乙酯、苯磺酸丙酯和苯磺酸异丙酯在1~1000 ng·mL-1内呈良好的线性关系,r≥0.998;方法准确度良好,平均加样回收率(n=10)分别为99.77%,100.19%,94.21%和92.43%。5个不同厂家生产的苯磺酸氨氯地平中苯磺酸甲酯的含量均<LOQ(8mg·g-1),苯磺酸乙酯、苯磺酸丙酯和苯磺酸异丙酯的含量均<LOQ(0.4mg·g-1)。结论该方法可用于苯磺酸氨氯地平中痕量基因毒性杂质苯磺酸甲酯、苯磺酸乙酯、苯磺酸丙酯和苯磺酸异丙酯含量的检测分析。

3种云南野生食用菌对鸡汤滋味和挥发性风味的影响

为研究3种云南野生食用菌炖煮对鸡汤风味的影响,以500日龄的淘汰蛋鸡和3种云南野生食用菌(松露、牛肝菌和松茸)为原料,利用液相色谱-三重四极杆-质谱法(liquid chromatography-triple quadrupole mass spectrometry,LC-QQQ-MS)和顶空固相微萃取-气相色谱-质谱(headspace solid phase microextraction-gas chromatography-mass spectrometry,HP-SPME-GC-MS)技术分析未添加和添加3种云南野生食用菌鸡汤中游离氨基酸和挥发性风味物质的变化,探讨3种野生食用菌对鸡汤滋味和风味的影响。4种鸡汤均检测出17种游离氨基酸。与空白组相比,添加野生食用菌的鸡汤中氨基酸含量和对鸡汤滋味有特殊贡献的氨基酸种类显著增多;4种鸡汤中分别检出62、69、69种和73种挥发性风味化合物。添加3种云南野生食用菌后,鸡汤中风味物质种类、含量发生明显改变,气味活度值(odor activity value,OVA)分析显示,鸡汤特征挥发性风味成分也发生了明显改变。