Pharmacokinetic Analysis of Four Bioactive Iridoid and Secoiridoid Glycoside Components of Radix Gentianae Macrophyllae and Their Synergistic Excretion by HPLC-DAD Combined with Second-Order Calibration

An HPLC-DAD method combined with second-order calibration based on the alternating trilinear decomposition(ATLD)algorithm with the aid of region selection was developed to simultaneously and quantitatively characterize the synergistic relationships and cumulative excretion of the four bioactive ingredients of Radix Gentianae Macrophyllae in vivo.Although the analytes spectra substantially overlapped with that of the biological matrix,the overlapping profiles between analytes and co-eluting interferences can be successfully separated and accurately quantified by the ATLD method on the basis of the strength of region selection.The proposed approach not only determined the content change but also revealed the synergistic relationships and the cumulative excretion in vivo of the four ingredients in urine and feces samples collected at different excretion time intervals.In addition,several statistical parameters were employed to evaluate the accuracy and precision of the method.Quantitative results were confirmed by HPLC-mass spectrometry.Satisfactory results indicated that the proposed approach can be utilized to investigate the pharmacokinetics of Radix Gentianae Macrophyllae excretion in vivo.

HPLC fingerprinting and quantification of gentiopicroside and loganic acid in Gentianae Macrophyllae Radix crude drugs

HPLC fingerprinting and quantification of gentiopicroside（GPS） and loganic acid（LA） in Gentianae Macrophyllae Radix（GMR） crude drugs were developed in this study.The samples were separated on Zorbax SB-C_（18） column（250 mm×4.6 mm, 5μm） with a linear gradient of acetonitrile and 0.04%phosphoric acid.The HPLC flow rate was 1.0 mL/min and a UV absorption was measured at 230 nm.An orthogonal L9（3^4） test was applied for the optimization of sample extraction conditions,and an aliquot of GMR sample（g） was extracted with 15-fold of 50%ethanol（mL） for 30 min by sonication.Quantitative analysis showed that the content of GPS（14.05 mg/g-74.61 mg/g） in all samples was obviously higher than that of LA（1.13 mg/g-40.46 mg/g）. Based on the content ratio of GPS over LA（1.8-11.4）,samples originated from Gentiana macrophylla（with content ratio of GPS over LA≤4.3） could be distinguished from those from G.dahurica and G.dahurica var.gracilipes（with content ratio of GPS over LA≥4.8）.The principle components analysis of the HPLC fingerprints showed that samples originated from G.macrophylla and G.dahurica（including G.dahurica var.gracilipes） could be divided into two groups.This established HPLC-DAD method could be efficiently used for the species identification and quality control of GMR crude drugs.

Chemical fingerprint analysis of Gentianae Radix et Rhizoma by high-performance liquid chromatography

Gentianae Radix et Rhizoma(also called "Longdan" in Chinese)is commonly used for eliminating damp-heat and quenching the fire of liver and gall bladder in traditional Chinese medicine.In this study,a novel and reliable method using high-performance liquid chromatography(HPLC)was developed both for quantitative analysis of four bioactive compounds(loganic acid,swertiamarin,gentiopicroside and sweroside)and chemical fingerprint analysis of "Longdan".In quantitative analysis,four compounds showed good regressions(R^(2)>40.9987)within the test ranges and the recovery of the method was in the range 97.61-102.49%.In fingerprint analysis,ten characteristic peaks were selected to evaluate the similarities of the crude drugs,and the HPLC chromatograms of twenty samples from different regions of China showed similar patterns.The results demonstrated that the combination of the quantitative and chromatographic fingerprint analyses offered an efficient way to evaluate the quality consistency of Gentianae Radix et Rhizoma.