Determination of Paeoniflorin in Rat Plasma by Ultra-high Performance Liquid Chromatography-Tandem Mass Spectrometry and its Application to a Pharmacokinetic Study.
In this study, a rapid and highly sensitive ultra-high performance liquid chromatography-tandem mass spectrometry method was established for the quantification of paeoniflorin in rat plasma. The analyte and the internal standard (IS), hyperoside, were extracted from rat plasma via liquid-liquid extraction with ethyl acetate. LC separation was carried on a Phenomenex Luna C18 column within 2.5 min. Quantitation was performed on a triple quadrupole mass spectrometer employing electrospray ionization and operated in the multiple reaction monitoring and negative ion modes. The precursor to product ion transitions monitored for paeoniflorin and the IS were m/z 524.8→449.0 and 463.1→300.0, respectively. The assay was validated with a linear range of 0.02~25.6 μg/mL for paeoniflorin. The intra- and inter-day precisions (relative standard deviation%) were within 9.7%, and the recoveries were greater than 65.2%. Paeoniflorin was proven to be stable during all sample storage, preparation and analytical procedures. The method was successfully applied to a pharmacokinetic study of the Baixiangdan Capsule in eight female rats.
Effects of paeoniflorin on HPA axis and monoamine neurotransmitters in the rats of syndrome of stagnation of liver qi and blood deficiency
Objective: To investigate the nourishing blood and smoothing the liver mechanism and material basis of white peony root on the rats of syndrome of white peony root of liver qi and blood dei ciency by analyzing the inl uence of paeonil orin on hypothalamic-pituitary-adrenal axis and monoamine neurotransmitter in hippocampus. Methods: 70 SD male rats were randomly divided into seven groups which recorded as normal group, model group, l uoxetine group, Siwu group, 10mg/kg paeonil orin group, 20mg/kg paeonil orin group, 40mg/kg paeonil orin group. Excepted the normal group the rats in the other groups were prepared by chronic restraint stress combined with radiation respectively for 21 days to establish the model of syndrome of stagnation of liver qi and blood dei ciency. The rats in the administration groups and normal group were fed with medicines and pure water from the i rst day of the experiment, respectively. Sucrose preference test, open i eld test and stepdown test were carried on to test the neurobehavioral changes of rats, and weight and peripheral blood hemogram were also measured. After model establishing, the blood was taken and used to test the content of adrenocorticotrophic hormone(ACTH), corticosterone(CORT). Corticotropin releasing hormone(CRH) mRNA in hypothalamus, 5-hydrocytryptamine(5-HT) and dopamine(DA) in hippocampus were also measured. Results: Compared with the model group, the amount of WBC and RBC of paeonil orin group increased, sucrose consumption increased signii cantly, and the weight of the rats increased signii cantly. Number of horizontal and vertical climbing frames in open i eld test of rats in paeonil orin group increased. The ACTH content of the paeonil orin group was increased obviously, while 5-HT and DA in hippocampus increased obviously. Conclusion: The mechanism of nourishing blood and smoothing the liver with paeonil orin which was the active component of white peony root might be related to adjusting the HPA axis and monoamine neurotransmitters.
Sterol metabolism. XLI. Cholesterol A-ring autoxidations
Abstract Chromatographic and spectral evidence is adduced for the presence of cholest-5-en-3-one, cholest-4-en-3-one, and cholest-4-ene-3,6-dione in samples of cholesterol aged naturally in air or subjected to irradiation in air by 60 Co gamma radiation. These findings establish an additional mode of air oxidation of cholesterol to A-ring 3-ketones. Moreover, the oxidation by air of cholest-5-en-3-one induced by 60 Co gamma radiation yielded cholest-4-en-3-one, cholest-4-ene-3,6-dione, and the epimeric 3-oxocholest-4-ene-6-hydroperoxides. Cholest-4-en-3-one was not altered by irradiation in air, nor was cholesterol isomerized to cholest-4-en-3β-ol upon irradiation. From these observations it is deduced that the radiation-induced A-ring dehydrogenation of cholesterol yields initially cholest-5-en-3-one which upon isomerization yields cholest-4-en-3-one not further oxidized and which by a second oxidation yields the epimeric 3-oxocholest-4-ene-6-hydroperoxides which decompose to cholest-4-ene-3,6-dione.