[Determination of trigonelline by HPLC and study on its pharmacokinetics].
OBJECTIVE
To develop a sensitive and specific HPLC method for determination of trigonelline in rabbit plasma, and study the pharmacokinetics in rabbit.


METHODS
After ig of fenugreek extract and i.v. of trigonelline in rabbit, the biological samples could be well purified after precipitation of protein with methanol and acetonitrile. Asahipak NH2P-50 column was used, the mobile phase consisted of acetonitrile-water (90:10) at a flow-rate of 1.2 mL.min-1, and detection wavelength was set at UV 265 nm. The column temperature is 30 degrees C.


RESULTS
The calibration curve was linear in the range from 0.98 mg.L-1 to 31.28 mg.L-1, with r = 0.9986, the detection limit of this method was 50 micrograms.L-1. The concentration-time curves of trigonelline in rabbits after ig and i.v. administration were shown to fit one-compartment and two-compartment open model, respectively. The main parameters after ig of fenugreek extract were as follow: T1/2(Ka) was 0.9 h, T1/2(Ke) was 2.2 h, V was 0.64 L.kg-1, AUC was 1.93 mg.min.L-1. The main parameters after i.v. of trigonelline were as follows: T1/2 alpha was 10.8 min, T1/2 beta was 44.0 min, K21 was 0.044 min-1, K10 was 0.026 min-1, K12 was 0.017 min-1, AUC was 931.0 mg.min.L-1.


CONCLUSIONS
Trigonelline showed a middle rate of absorption and fast rate of elimination in rabbit. Meanwhile, the method is simple, accurate, with a good reproducibility, and it provide a basic method for the investigation of trigonelline and fenugreek pharmacokinetics.
Zhao
Huai-qing
HQ
Pharmaceutical College, Shenyang Pharmaceutical University, Shenyang 110016, China. zhqzcxy@online.ln.cn
Qu
Yan
Y
Wang
Xue-ya
XY
Lu
Xin-yan
XY
Zhang
Xue-hang
XH
Hattori
Masao
M
D000470:Alkaloids / Q000097:blood / Q000302:isolation & purification / Q000493:pharmacokinetics*; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000097:blood / Q000302:isolation & purification / Q000493:pharmacokinetics; D019540:Area Under Curve; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004365:Drugs, Chinese Herbal / Q000302:isolation & purification / Q000493:pharmacokinetics*; D005260:Female; D008297:Male; D010946:Plants, Medicinal / Q000737:chemistry; D011817:Rabbits; D012639:Seeds / Q000737:chemistry; D029910:Trigonella / Q000737:chemistry*
D000470:Alkaloids; D000972:Antineoplastic Agents, Phytogenic; D004365:Drugs, Chinese Herbal; C009560:trigonelline