**1. Introduction**

The geographical origin and the authenticity of herbal material are often related to the safe application of their preparations, since the authenticity and quality parameters are often associated with a particular geographical origin and/or production area [1]. However, some herbal products available for purchase do not come from a fixed origin, and could fall short of quality requirements. Thus, the successful traceability of geographical origin attributes is necessary for ensuring efficacy and biosafety [2]. Metabolites are the end product of the majority of cellular processes, and, as such, are representative of the phenotype of an organism. The secondary metabolites of herbs with different geographical origins exhibit certain differences, therefore, it has been speculated that different

geographical origins of medicinal herbs may be identified according to their chemical characteristics by a data mining method based on their chemical profiles [3].

The root of *Gentiana straminea* (*G. straminea*) Maxim. (Gentianaceae) is officially listed as "Qin-Jiao" in the Chinese Pharmacopoeia [4] for the treatment of rheumatic arthritis, icteric hepatitis, constipation, pain, and hypertension [5]. Phytochemical investigations have characterized the plant by the presence of a wide range of compounds, such as iridoids, secoiridoids, flavonoids, triterpenoids, alkaloids, and other types of secondary metabolites [6–8]. Some published methods have focused on the qualitative and quantitative determination of iridoids and secoiridoids in the plant by liquid chromatography or liquid chromatography-mass spectrometry [9,10]. Nevertheless, few of these methods have been aimed at determining the geographical origin of *G. straminea* by characteristic marker components.

In recent years, the authors of this paper successfully identified the characteristic components in different geographical origins of *Lamiophlomis rotata* by ultra-high performance liquid chromatography coupled with time-of-flight mass spectrometry (UPLC-Q/TOF/MS) [11–13]. Here, a comprehensive chemical composition analysis of 42 samples is proposed to evaluate the variability of *G. straminea* from different geographical origins, with sensitive, selective, and accurate UPLC-Q exactive mass spectrometer analysis. The UPLC-Q exactive mass spectrometer data was assayed to identify the characteristic components in *G. straminea* from different geographical regions. Partial least-squares discriminant analysis (PLS-DA) and orthogonal partial least-squares discriminant analysis (OPLS-DA) were employed with a metabolomic approach. To estimate the key characteristic marker associated with pharmacological function, the inhibiting activities of nitric oxide (NO) production in lipopolysaccharide (LPS)-induced macrophages were examined. In summary, the findings of this study imply that the origin of the material should be considered when it is used in traditional prescriptions and medicinal preparations.
