Rhizosphere microbes influence wogonoside accumulation in perennial Scutellaria baicalensis

Dried roots of Scutellaria baicalensis Georgi are an acclaimed traditional Chinese medicine,and wogonoside content is a key indicator used to evaluate S.baicalensis quality.Rather than rising linearly with cultivation years,S.baicalensis quality initially increases and then declines.However,little is known regarding the dynamic variations in S.baicalensis rhizosphere microorganisms under long-term cultivation and underlying mechanisms of their effects on wogonoside formation and accumulation.The aim of this study was to investigate the roles of soil nutrients and rhizosphere microbes on S.baicalensis quality across different cultivation years(1-4 years).The wogonoside content(25.14 mg g^(-1))was highest in the biennial S.baicalensis and then decreased following long-term cultivation.Most soil nutrients(available nitrogen,available phosphorus,available iron,available manganese,and available zinc)were reduced significantly as cultivation years increased.Time also affected rhizosphere bacterial community structure significantly,driving it toward deterministic process(i.e.,β-nearest taxon index<-2).Available manganese and exchangeable calcium indirectly affected wogonoside formation and accumulation.Wogonoside inhibition was driven by the reduction in rhizosphere bacterial diversity,which significantly increased the relative abundance of beta-glucosidase and decreased the relative abundance of phenylalanine ammonialyase.The rhizosphere microenvironment was altered under long-term cultivation,thereby shaping rhizosphere bacterial community,reducing the community diversity,and ultimately inhibiting wogonoside formation and accumulation.Our findings may aid in understanding of the mechanisms and reasons for the reduction in S.baicalensis quality under long-term cultivation from the perspective of soil nutrients and microorganisms,which may theoretically support the future artificial cultivation and management of Chinese medicinal plants.

Simultaneous Determination of Effective Components of Gegen Qinlian Tablets by HPLC

[Objectives]To establish a HPLC method for the simultaneous determination of 14 characteristic components in Gegen Qinlian tablets and the content of Gegen Qinlian tablets in 11 manufacturers.[Methods]A Inertsil ODS-3(250 mm×4.6 mm,5μm)reversed-phase high performance liquid chromatography column was used with acetonitrile-0.02 mol/L ammonium acetate+0.03%triethylamine solution(adjusted with glacial acetic acid to pH of 4.3)as the mobile phase for gradient elution at a flow rate of 1.0 mL/min.The determination wavelength of 8 components(puerarin,daidzin,liquiritin,baicalin,wogonoside,daidzein,ammonium glycyrrhizinate,baicalein)was 250 nm;the determination wavelength of wogonoside was 280 nm;the determination wavelength of 5 components(epierberine,jatrorrhizine hydrochloride,coptisine,palmatine hydrochloride and berberine hydrochloride)was 346 nm.[Results]There was a good linear relationship between the injection volume of puerarin,daidzin,liquiritin,baicalin,wogonoside,epierberine,jatrorrhizine hydrochloride,coptisine,daidzein,palmatine hydrochloride,ammonium glycyrrhizinate,berberine hydrochloride,baicalein and wogonin and peak area(r>0.9990)in the range of 146.26-5850.24,24.13-965.04,18.45-738.00,79.18-3167.32,9.57-382.80,4.76-190.40,2.57-102.80,13.41-536.40,10.60-424.00,11.33-453.22,12.08-483.20,46.73-1869.25,20.28-811.20,12.11-484.50 ng,respectively;the average recovery rates(n=6)were 2.18%,1.79%,1.81%,1.68%,2.27%,2.13%,1.96%,1.07%,0.93%,0.61%,2.92%,0.77%,2.79%and 0.62%,respectively;the precision,repeatability and stability were good,and the RSD was less than 3%.This method was used to determine 16 batches of Gegen Qinlian tablets produced by 11 enterprises.Wogonoside was not detected in a lot of samples,but 14 components were detected for other enterprises,but the content was different.[Conclusions]The method was accurate and feasible and could be used for the overall quality control of this variety.

HPLC–MS and HPLC–MS/MS analysis of seven active constituents of Xiao-Xu-Ming decoction and application to a pharmacokinetic study after oral administration to rat

Xiao-xu-ming decoction(XXMD)is a traditional Chinese medicine that has been widely used to treat theoplegia and its sequelae.This paper reports the development of three separate assays based on reversed phase high-performance liquid chromatography–mass spectrometry(HPLC–MS)and HPLC–MS/MS for the determination of seven active constituents of XXMD viz oroxylin A-7-O-glucuronide,wogonoside,liquiritigenin,cimifugin,5-O-methylvisammiol,glycyrrhizic acid and glycyrrhetinic acid in rat plasma.All calibration curves were linear(r >0.99)with lower limits of quantitation(LLOQs)<12.4 ng/mL.Intra-and inter-day precisions(as relative standard deviation)were all <10.7% with recoveries in the range of 88.7–113%.In addition,the seven analytes were shown to be stable in rat plasma samples under relevant storage conditions.The validated methods were successfully applied to a pharmacokinetic study in rat after oral administration of XXMD.