Establishment and application of a new HPLC qualitative and quantitative assay for Gentiana Macrophyllae Radix based on characteristic constituents of anofinic acid and its derivatives.

Gentiana Macrophylla Radix (GMR) is officially used as traditional Chinese medicine, but easily confused with Gentianae Radix et Rhizoma (GRR) and adulterants. This study aimed to establish an HPLC method for qualitative and quantitative analysis of GMR based on characteristic components, anofinic acid and its derivatives. HPLC analysis was performed on a C18 column with gradient elution using acetonitrile and 0.1% phosphoric acid as mobile phase, and detected at 240 nm by conventional methodology validation. For fingerprint analysis, RSDs of relative retention times and relative peak areas of the characteristic peaks were within 0-1.10 and 0-4.08%, respectively. For determination of 2-methoxyanofinic acid, the calibration curve showed good linearity (R2  > 0.9999) within the test range. The RSDs of precision, repeatability and stability test did not exceed 2.46, 0.83 and 1.11%, respectively. The average recoveries were between 95.08 and 103.05% with RSDs ≤2.29%. The results showed that there was no significant difference among the four species of GMR, but there were significant differences among GMR, GRR and spurious breeds by principal component analysis and hierarchical cluster analysis. Anofinic acid and its derivatives, as the characteristic markers, could be used for the identification and quality control of GMR.