Search

The metabolic and pharmacokinetic studies on complanatuside, a quality marker of a Chinese materia medicatonic, Semen Astragali Complanati, were carried out. The UHPLC-Q-TOF/MS (ultra-high performance liquid chromatography coupled with electrospray ionization tandem quadrupole-time-of-flight mass spectrometry) method was applied to identify the metabolites of complanatuside in rat plasma, bile, stool, and urine after oral administration at the dosage of 72 mg/kg. Up to 34 metabolites (parent, 2 metabolites of the parent drug, and 31 metabolites of the degradation products) were observed, including processes of demethylation, hydroxylation, glucuronidation, sulfonation, and dehydration. The results indicated glucuronidation and sulfonation as major metabolic pathways of complanatuside in vivo. Meanwhile, a HPLC-MS method to quantify complanatuside and its two major metabolites—rhamnocitrin 3-O-β-glc and rhamnocitrin—in rat plasma for the pharmacokinetic analysis was developed and validated. The Tmax (time to reach the maximum drug concentration) of the above three compounds were 1 h, 3 h, and 5.3 h, respectively, while the Cmax (maximum plasma concentrations)were 119.15 ng/mL, 111.64 ng/mL, and 1122.18 ng/mL, and AUC(0-t) (area under the plasma concentration-time curve) was 143.52 µg/L·h, 381.73 µg/L·h, and 6540.14 µg/L·h, accordingly. The pharmacokinetic characteristics of complanatuside and its two metabolites suggested that complanatuside rapidly metabolized in vivo, while its metabolites—rhamnocitrin—was the main existent form in rat plasma after oral administration. The results of intracorporal processes, existing forms, and pharmacokinetic characteristics of complanatuside in rats supported its low bioavailability. [ABSTRACT FROM AUTHOR]

This study has developed a reliable and precise high performance liquid chromatography-tandem mass spectrometry method for the simultaneous determination of five phenolic acids and four flavonoid glycosides in rat plasma after a single intravenous administration of Kudiezi injection (KI). Chromatographic separation was carried out on an Ultimate®XB-C18 column (4.6 × 100 mm, 3.5 μm) using a gradient elution program with a mobile phase consisting of water containing 0.5% acetic acid and acetonitrile at a flow rate of 0.6 mL/min. Detection was performed on a triple-quadrupole tandem mass spectrometry using multiple reaction monitoring in negative electrospray ionization mode. The calibration curves of all analytes showed good linearity (R2 > 0.990). The results of selectivity, intra-day and inter-day precisions, extraction recoveries, matrix effects and stability were satisfactory. Pharmacokinetic parameters showed that luteolin-7-O-β-d-gentiobioside, luteolin-7-O-β-d-glucuronide, luteolin-7-O-β-d-glucoside and apigenin-7-O-β-d-glucuronide were eliminated quickly (0.07 h < t1/2 < 0.66 h), whereas 5-caffeoylquinic acid, caftaric acid, chlorogenic acid, 4-caffeoylquinic acid and caffeic acid were eliminated relatively slowly (2.22 h < t1/2 < 6.09 h) in rat blood. The pharmacokinetic results would be valuable to identify bioactive constituents, elucidate mechanisms of pharmacological actions or adverse drug reactions and guide the rational clinical use of KI. [ABSTRACT FROM AUTHOR]