Metabolomics Combined with Multivariate Statistical Analysis for Screening of Chemical Markers between Gentiana scabra and Gentiana rigescens

Gentianae Radix et Rhizome (Longdan in Chinese, GRR) in Chinese Pharmacopoeia is derived from the dried roots and rhizomes of Gentiana scabra and G. rigescens, that have long been used for heat-clearing and damp-drying in the medicinal history of China. However, the characterization of the chemical components of two species and the screening of chemical markers still remain unsolved. In current research, the identification and characterization of chemical components of two species was performed using ultra-high-performance liquid chromatography (UHPLC) coupled with linear ion trap-Orbitrap (LTQ-Orbitrap) mass spectrometry. Subsequently, the chemical markers of two species were screened based on metabolomics and multivariate statistical analysis. In total, 87 chemical constituents were characterized in G. scabra (65 chemical constituents) and G. rigescens (51 chemical constituents), with 29 common chemical constituents being discovered. Thereafter, 11 differential characteristic components which could differentiate the two species were designated with orthogonal partial least squares discriminant analysis (OPLS-DA) and random forest (RF) iterative modeling. Finally, seven characteristic components identified as (+)-syringaresinol, lutonarin, trifloroside, 4-O-β-d-glu-trifloroside, 4″-O-β-d-glucopyranosy1-6′-O-(4-O-β-d-glucaffeoyl)-linearroside, macrophylloside a and scabraside were selected as the chemical markers for the recognition of two Gentiana species. It was implied that the results could distinguish the GRR derived from different botanical sources, and also be beneficial in the rational clinical use of GRR.

Concurrent Extraction and Purification of Gentiopicroside from Gentiana scabra Bunge Using Microwave-Assisted Ethanol-Salt Aqueous Two-Phase Systems

A potential method called microwave-assisted aqueous two-phase extraction (MA-ATPE) was developed for concurrent extraction and purification of gentiopicroside from Gentiana scabra Bunge. Formation characteristics of aqueous two-phase system (ATPS) composed of ethanol and 25 kinds of salts were investigated; K2HPO4 (w/w, 21.71%) and ethanol (w/w, 40.72%) were determined to be the optimal compositions of ATPS. Response surface methodology based on Box–Behnken design was used to investigate the extraction conditions, the optimal parameters were summarized as follows: 80°C of extraction temperature, 31 s of extraction time, 11:1 (mL/g) of liquid-to-solid ratio, 100 meshes of particle size and 806 W of microwave power. Under these conditions, the extraction yield of gentiopicroside was 65.32 ± 0.24 mg/g with a recovery of 96.51%. Compared with other four methods, the purity of gentiopicroside in the crude extracts reached 17.16 ± 0.25%, which was significantly higher than that of smashing tissue extraction, microwave assisted-extraction, ultrasonic-assisted extraction and heat reflux extraction, respectively. In addition, the phase-forming salt can be recyclable. Therefore, MA-ATPE was an excellent and alternative technique to the conventional extraction approaches of gentiopicroside.

Nitrogen doped carbon materials derived from Gentiana scabra Bunge as high-performance catalysts for the oxygen reduction reaction

Gentiana scabraBunge-derived porous carbon materials as high-performance catalysts for the oxygen reduction reaction in both acidic and alkaline solutions were introduced.