Biomedical subjects

Qingfei Liu

Publications and source records attributed to Qingfei Liu.

6 recordsLinked to original sources

PubMed2006

Simultaneous determination of geniposide, baicalin, cholic acid and hyodeoxycholic acid in rat serum for the pharmacokinetic investigations by high performance liquid chromatography-tandem mass spectrometry.

A simple, rapid, and specific analytical method for simultaneous determination of geniposide, baicalin, cholic acid and hyodeoxycholic acid in 50 microL samples of rat serum was developed by high performance liquid chromatography-tandem mass spectrometry. The quantification of the target compounds was determined by multiple reaction monitoring (MRM) mode using electrospray ionization (ESI). The correlation coefficients of the calibration curves were better than 0.997. The intra- and inter-day accuracy, precision, and linear range had been investigated in detail. This method was subsequently applied to pharmacokinetic studies of geniposide, baicalin, cholic acid and hyodeoxycholic acid in rats successfully.

Animals↗

PubMed2006

Determination of helicidum and its metabolites in dog plasma by LC/UV/MS/MS and its application to pharmacokinetic studies.

A simple, rapid and reliable method was developed for the identification and quantification of helicidum and its metabolites in beagle dog plasma by liquid chromatography/ultra-violet/electrospray ionization-ion trap mass spectrometry (LC/UV/ESI-ITMS). Two metabolites were identified by MS: formylphenyl-O-beta-d-pyranosyl alloside (I) and hydroxylmethylphenyl-O-beta-d-pyranosyl alloside (II). UV was used for concentration determination with the wavelength of 270 nm. Liquid-liquid extraction was used and the extraction recovery exceeded 90%. Kromacil C(18) column (5 microm, 4.6mm i.d. x 250 mm) was used as the analytical column. Linear detection responses were obtained for helicidum concentration ranging from 1.76 x 10(-4) to 70.4 x 10(-4) micromol/mL (0.050-2.00 microg/mL). The precision and accuracy data, based on intra- and inter-day variations over 3 days, were less than 5%. The limit of determination and quantitation (LOD, LOQ) for helicidum was 0.010 and 0.030 microg/mL, respectively. Pharmacokinetic data of helicidum and the two metabolites were obtained with this method after administration of intravenous injection and a single oral dose of tablets to six beagle dogs, respectively.

Animals↗

PubMed2005

[Pharmacokinetics of breviscapine in dogs and rabbits following single intravenous administration].

OBJECTIVE: To study pharmacokinetics of breviscapine in dogs and rabbits after iv. single dose. METHODS: Lc/Lc extract was used to prepare test samples and HPLC was used to determine breviscapine. RESULTS: Breviscaplin was fitted to double-department model in dogs and rabbits after iv. single dose. The main parameters in dogs were: A = 56.93 +/- 23.14, B = 1.61 +/- 1.11, alpha = 0.2328 +/- 0.1321 min, beta = 0.0255 +/- 0.0187 min(-1), t(1/2alpha) = 2.98 +/- 1.42 min, t(1/2beta) = 27.14 +/- 14.35 min, K21 = 0.10312 +/- 0.0112 min(-1), K10 = 0.1904 +/- 0.1319 min(-1), K12 = 0.0367 +/- 0.0306 min(-1), CL = 39.41 +/- 20.44 ml x min(-1), AUC = 3074 +/- 1055 mg x min x L(-1), respectively. The main parameters in rabbits were:A = 2.64 +/- 1.12, B = 0.28 +/- 0.12, alpha = 0.1439 +/- 0.0681 min(-1), beta = 0.0162 +/- 0.0456 min(-1), t1/2alpha = 4.82 +/- 1.65 min, th1/2beta = 42.66 +/- 18.77 min, K21 = 0.0285 +/- 0.0147 min(-1), K10 = 0.0820 +/- 0.00378 min(-1), K12 = 0.0496 +/- 0.0241 min, CL = 337.05 +/- 156.48ml x min(-1), AUC = 356 +/- 114 mg x min x L(-1), respectively. CONCLUSION: Breviscapine has short half-life after intravenous administration to dogs and rabbits,which show breviscapine is eliminated rapidly and has short action time.

Animals↗

PubMed2004

[Determination of GA, GB and GC in total lactone of ginkgo (TLG) raw material].

OBJECTIVE: To determine the different lactone content of 10 batches of TLG raw material. METHODS: RP-HPLC-ELSD were used to determine ginkgolide A, B, C(GA, GB, GC). RESULTS: Content of GA, GB and GC were different but TLG very high (all > 90%). CONCLUSION: The quality of TLG could be affected by habitat, season and the preparation method.

Chromatography, High Pressure Liquid↗

PubMed2002

[Depiction of ultraviolet spectrum group draft of EGB761].

By the combinative method of fingerprint spectrums, the ultraviolet spectrum group draft of EGB761 was depicted. The established method is characteristic and reproducible and can be used in the identification and quality control of the medical materials, extracts and preparations. The ultraviolet spectrum group draft of EGB761 was tentatively depicted as: lambda max (nm): H2O solution (C = 0.02 mg/ml) 265.00 +/- 1.00, 201.00 +/- 1.00; EtOH solution (C = 0.02 mg/ml) 267.00 +/- 1.00, 210.00 +/- 1.00; CHCl3 solution (C = 0.4 mg/ml) 241.00 +/- 1.00; petroleum benzine solution (C = 0.4 mg/ml) 211.00 +/- 1.00.

Ethanol↗

PubMed2002

[Morphological and histological study on Pteris multifida].

The thesis studies on the pharmacognostical characteristics of Pteris multifida were carried out in this paper. The blade has special vein-like cell. The stomas in dorsal epidermis are regular. The petiol has V-shaped amphicribral bundles. The rhizome has 6-8 meristeles. The triangle-form spore has tumor-shaped or pellet-shaped decorations on its surface.

Pharmacognosy↗