The Use of DNA Barcoding on Recently Diverged Species in the Genus Gentiana (Gentianaceae) in China.

DNA barcoding of plants poses particular challenges, especially in differentiating, recently diverged taxa. The genus Gentiana (Gentianaceae) is a species-rich plant group which rapidly radiated in the Himalaya-Hengduan Mountains in China. In this study, we tested the core plant barcode (rbcL + matK) and three promising complementary barcodes (trnH-psbA, ITS and ITS2) in 30 Gentiana species across 6 sections using three methods (the genetic distance-based method, Best Close Match and tree-based method). rbcL had the highest PCR efficiency and sequencing success (100%), while the lowest sequence recoverability was from ITS (68.35%). The presence of indels and inversions in trnH-psbA in Gentiana led to difficulties in sequence alignment. When using a single region for analysis, ITS exhibited the highest discriminatory power (60%-74.42%). Of the combinations, matK + ITS provided the highest discrimination success (71.43%-88.24%) and is recommended as the DNA barcode for the genus Gentiana. DNA barcoding proved effective in assigning most species to sections, though it performed poorly in some closely related species in sect. Cruciata because of hybridization events. Our analysis suggests that the status of G. pseudosquarrosa needs to be studied further. The utility of DNA barcoding was also verified in authenticating 'Qin-Jiao' Gentiana medicinal plants (G. macrophylla, G. crassicaulis, G. straminea, and G. dahurica), which can help ensure safe and correct usage of these well-known Chinese traditional medicinal herbs.

[Study on identification of four kinds of Gentianaceae Mongolian medicine Digeda with spectroscopy techniques].

To study the identification of Gentianaceae Mongolian medicine Digeda with spectroscopy techniques, near infrared spectroscopy and differential scanning calorimetry techniques were applied to study on the identification of 4 kinds of Gentianaceae Mongolian medicine Digeda, and characteristic spectrums obtained were systematically analyzed. In NIR study, the four species of Digeda exist some differences in 4 250-4 400 cm(-1) and 5 650-5 800 cm(-1) of one-dimensional spectra, and show significant differences in 4 100- 4 400 cm(-1), 4 401-4 900 cm(-1) and 5 400-5 800 cm(-1) of the second derivative spectra. DSC curves of them present distinct topological pattern, characteristic peak and peak temperature. Using near infrared spectroscopy and differential scanning calorimetry analysis can realize efficient and accurate identification of four kinds of Mongolian medicine Digeda, and provide scientific basis for the efficient and accurate identification of other Gentianaceae Mongolian medicine Digeda.

[Preliminary comparative study of swertiamarin and swertisin on three kinds of Digeda-species Mongolian medicinal materials].

Lomatogonium rotatum (L.) Fries, Gentianopsis barbata (Froel) Ma, and Gentianella acuta (Michx.) Hulten, the three kinds of Digeda-species Mongolian medicinal materials belonging to the family Gentianaceae, bad been widely used for the treatment of liver diseases. To analyze comparatively the content of swertiamarin and swertisin among these three kinds of Digeda-species Mongolian medicinal materials. HPLC method was applied for qualitative and quantitative analysis of swertiamarin and swertisin. The Phenomenex C18 (4.6 mm x 250 mm, 5 µm) was used, chromatographic methanol and water as mobile phase, the flow rate was 1.5 mL x min(-1) with UV detected at 237 nm, column oven temperature was 25 degrees C. Results showed that the contents of swertiamarin and swertisin were closely related the different species and producing areas. The content range of swertiamarin in L. rotatum from different habitats was 1.73% - 2.72%, 0.43% - 0.96% for the swertisin content; the content of swertiamarin in G. barbata from Alxa Left Banner was 0.38%, and the content of swertiamarin and swertisin in G. barbata from the others habitats and G. Acuta from different habitats were all detected qualitatively. The contents of swertiamarin and swertisin among these medicinal plants showed a significant difference due to the different species and producing areas. As a consequence, these medicinal plants should not be put together for clinical applications.

[Difference of chemical constituents contained in Tibetan herb Jiadiranguo from different habitats by HPLC fingerprint].

OBJECTIVE: To establish the HPLC fingerprint for Halenia elliptica herbs, a traditional Tibetan medicine, in order to study constituents contained in H. elliptica from different habitats and compare their differences. METHOD: HPLC analysis was made on a Welchrom-C18 (4.6 mm x 250 mm, 5 microm) with water and acetonitrile as mobile phase. The wavelength was detected as 265 nm, the flow rate was 1.0 mL x min(-1), and the column temperature was 40 degrees C. The software for chromatographic fingerprint was applied to analyze the similarity. And principal component analysis was conducted. RESULT: Twelve common chromatographic peaks were identified by fingerprint, showing a low similarity in constituent and variety. The significant difference in the proportion between xanthones and aglycones in each batch of herbs indicated no notable correlation between constituent characteristics and geographic locations of habitats. CONCLUSION: The method is so simple, exclusive, stable and highly repeatable that it can provide reference for identification and quality assessment of H. elliptica herbs.

Ultra-performance liquid chromatography/time-of-flight mass spectrometry as a chemotaxonomic tool for the analysis of Gentianaceae species.

INTRODUCTION: The segregation between the genera Gentiana and Gentianella among the Gentianaceae family is poorly defined. In order to clarify the classification of these genera, some researchers have tried to incorporate data about the chemical constitution, but this has not yet been achieved in a comprehensive way. OBJECTIVE: To develop a fast and reproducible analytical method for the observation of characteristic fingerprints of secondary metabolites of each genus. METHODOLOGY: Seven species were investigated, three Gentianella and four Gentiana selected for their close taxonomic links within each genus. Ten xanthones previously isolated from one of these species were used as chemotaxonomic markers. A UPLC/ESI-TOF-MS method was developed to analyse the methanolic extracts. RESULTS: The UPLC/TOF-MS provided clear metabolic fingerprints and elemental composition of the compounds. The profiles of the three Gentianella species were strikingly similar. On the contrary, metabolic profiles of Gentiana species were very different from the Gentianella chromatograms and also from each other. Several compounds were unique to each genus and therefore could be used as biomarkers. CONCLUSION: UPLC/TOF-MS can be applied as a chemotaxonomic tool for the rapid screening of Gentianaceae species and for the distinction between closely related taxa from the Gentianaceae family.

[Study on HPLC fingerprint of Gentiana macrophylla].

OBJECTIVE: To establish HPLC fingerprint of Gentiana macrophylla, which was expected to be standards of quality control and identification of the Chinese crude drug. METHODS: The HPLC method was used, chromatography conditions were Shimadzu C18 (150 mm x 4.6 mm, 5 microm) column with gradient mobile phase of methanol-0.4% Phosphoric acid, UV detection wavelength was at 230 nm and the column temperature was at 25 degrees C with the flow rate of 1.0 ml/min. RESULTS: 5 peaks were identified as the characteristic fingerprints of Gentiana macrophylla and the fingerprints of the 14 samples had high similarities. The similarities of disqualified and fake medicinal materials were low. CONCLUSION: This HPLC fingerprint of Gentiana macrophylla can be used as a standard of quality control and identification of the Chinese crude drug.