Simultaneous Determination of Baicalein, Baicalin, Wogonin, and Wogonoside in Rat Plasma by LC-MS/MS for Studying the Pharmacokinetics of the Standardized Extract of Scutellariae Radix

Abstract

A new composition of standardized Scutellariae Radix extract (HPO12) was developed for treatment of Alzheimer's disease. For the preclinical pharmacokinetic study of HPO12, a rapid, sensitive, and selective LC-MS/MS method was developed and validated for the simultaneous determination of 4 bioactive compounds, baicalein, baicalin, wogonin, and wogonoside. After extraction with ethylacetate, chromatographic analysis was performed on a Thermo C 18 column (150 mm × 2.1 mm, 3 μm) with a mobile phase consisting of 0.1% formic acid (A) and 0.1% formic acid in 95% acetonitrile (B) by using gradient elution at a flow rate of 250 μL/min. Analytes introduced to a mass spectrometer were monitored by multiple reaction monitoring (MRM) in positive ion mode. Using 25 μL of plasma sample, the method was validated over the following concentration ranges: 25-5000 ng/mL for baicalein, 20-40000 ng/mL for baicalin, 1-1000 ng/mL for wogonin, and 5-10000 ng/mL for wogonoside. The intra-and inter-day precision and accuracy of the quality control samples at the 4 concentrations showed ≤ 13.7% relative standard deviation (RSD) and 86.6-105.5% accuracy. The method was successfully applied to determine the concentrations of baicalein, baicalin, wogonin, and wogonoside in rat plasma after intraperitoneal and oral administrations of HPO12.

Chenopodium murale Juice Shows Anti-Fungal Efficacy in Experimental Oral Candidiasis in Immunosuppressed Rats in Relation to Its Chemical Profile

“…Fragmentation due to the loss of 14 amu was detected for the methyl, the loss of 18 amu for the hydroxyl and the loss of 30 amu for the methoxy groups (Figure 3). Baicalein-7-Oglucuronide was detected for the first time, proposed for peak 11, with a molecular ion peak at m/z 445.0777, R t 5.856 min, and a molecular formula of C 21 H 18 O 11 [28].…”

Controlled Extraction of Flavonoids From Radix Scutellariae by Subcritical Water

“…The flow rate was set at 1 mL/min, and the injection volume was 20 µL. The gradient was 45% solvent A and 55% solvent B . The concentration of flavonoids in the sample was obtained by using standard curves generated using a series of standard solutions.…”

Pharmacokinetics of B-Ring Unsubstituted Flavones

“…In the case of GL-V9, although a concentration peak was seen after 0.5 h of oral administration, a second twin peak was recorded after 12 h (in rats), most likely related to the enterohepatic, enteric, or local recycling [60]. A double peak was detected in the plasma concentration–time curves for baicalin, oroxin A (baicalein-7- O -glucoside), baicalein, wogonoside, wogonin, and chrysin when administered in rats, related to enterohepatic, local, or enteric recycling [16,23,32,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100]. In one study in rats, it was claimed that this bi-modal “behavior” was not confirmed experimentally [101], but the authors only measured plasma samples up to 180 min, whereas in order to observe the second peak (at its maximum) at least 6–8 h would often be needed [102,103,104,105], although in other cases a second peak was reported after only two to three hours [106,107,108,109]; in dogs, following i.v.…”