Identification of Gentiana rigescens from Different Geographical Origins based on HPLC and FTIR Fingerprints

Gentiana rigescens is a traditional Chinese medicine with the efficacy in liver protection, cholagogic, hyperglycemia, anti-hypertension, relieving spasm and pain. The geographical environment of each place is very complicated with different soil, climate, and sunshine and so on, which has a remarkable effect on the quality of medicinal herbs. To identify different geographic origins of G. rigescens, we analyzed high-performance liquid chromatography (HPLC) and Fourier transform infrared spectroscopy (FTIR) fingerprints of G. rigescens with the help of chemometrics. Five variable selection methods including competitive adaptive reweighted sampling (CARS), random frog (RF), subwindow permutation analysis (SPA), Monte Carlo uninformative variable elimination (MC-UVE) and genetic algorithm (GA) were used to screen the characteristic variables for both HPLC and FTIR fingerprints. Then, the corresponding partial least squares discriminant analysis（PLS-DA）models were built. The results showed that for both HPLC and FTIR, GA-PLS-DA models were the most robust models for identification of the geographical origins of G. rigescens, which indicated the recognition results of HPLC and FTIR are consist. Through HPLC-FTIR two-dimensional (2D) hetero-correlation analysis, the results showed a substantial correlation between HPLC and FTIR, which suggested spectral correlative chromatography for multicomponent comparison could be possible and conducted. In terms of G. rigescens, it is more convenient, fast, environment-friendly and low cost for qualitatively identification using FTIR than HPLC.