Triterpenoids and Iridoid Glycosides from Gentiana dahurica

A comprehensive review of phytochemistry, pharmacology and clinical application of Gentianae Macrophyllae Radix

Gentianae Macrophyllae Radix (GMR) is a traditional Chinese herb with the function of dispelling wind and dampness, and removing damp heat. Currently, it is reported in the literature that GMR mainly contains iridoids and secoiridoids, in addition to triterpenoids, flavonoids, lignans, steroids, alkaloids and other chemical components. Among them, iridoids and secoiridoids are the main active ingredients of GMR. Modern pharmacological studies have shown that GMR has pharmacological effects such as anti-inflammatory, anti-tumor, hepatoprotective, immunomodulatory and cardioprotective. In clinical practice, GMR is mainly used to treat rheumatoid arthritis, ulcerative colitis, stroke and other related diseases with good therapeutic effects. Currently, there are few literature reports on the GMR research progress. Therefore, this paper provides a review of the chemical composition, pharmacological activity and clinical applications of GMR to provide some scientific basis for the further development of plant resources.

Automated Composition Assessment of Natural Extracts: Untargeted Mass Spectrometry-Based Metabolite Profiling Integrating Semiquantitative Detection

Recent developments in mass spectrometry-based metabolite profiling allow unprecedented qualitative coverage of complex biological extract composition. However, the electrospray ionization used in metabolite profiling generates multiple artifactual signals for a single analyte. This leads to thousands of signals per analysis without satisfactory means of filtering those corresponding to abundant constituents. Generic approaches are therefore needed for the qualitative and quantitative annotation of a broad range of relevant constituents. For this, we used an analytical platform combining liquid chromatography-mass spectrometry (LC-MS) with Charged Aerosol Detection (CAD). We established a generic metabolite profiling for the concomitant recording of qualitative MS data and semiquantitative CAD profiles. The MS features (recorded in high-resolution tandem MS) are grouped and annotated using state-of-the-art tools. To efficiently attribute features to their corresponding extracted and integrated CAD peaks, a custom signal pretreatment and peak-shape comparison workflow is built. This strategy allows us to automatically contextualize features at both major and minor metabolome levels, together with a detailed reporting of their annotation including relevant orthogonal information (taxonomy, retention time). Signals not attributed to CAD peaks are considered minor metabolites. Results are illustrated on an ethanolic extract of Swertia chirayita (Roxb.) H. Karst., a bitter plant of industrial interest, exhibiting the typical complexity of plant extracts as a proof of concept. This generic qualitative and quantitative approach paves the way to automatically assess the composition of single natural extracts of interest or broader collections, thus facilitating new ingredient registrations or natural-extracts-based drug discovery campaigns.

Integrated Strategy From In Vitro, In Situ, In Vivo to In Silico for Predicting Active Constituents and Exploring Molecular Mechanisms of Tongfengding Capsule for Treating Gout by Inhibiting Inflammatory Responses

The study of screening active constituents from traditional Chinese medicine (TCM) is important for explicating the mechanism of action of TCM and further evaluating the safety and efficacy effectively. However, detecting and identifying the active constituents from complicated biological samples still remain a challenge. Here, a practical, quick, and novel integrated strategy from in vitro, in situ, in vivo to in silico for rapidly screening the active constituents was developed. Firstly, the chemical profile of TCM in vitro was identified using UPLC-Q Exactive-Orbitrap HRMS. Secondly, the in situ intestinal perfusion with venous sampling (IPVS) method was used to investigate the intestinal absorption components. Thirdly, after intragastric administration of the TCM extract, the in vivo absorbed prototype components were detected and identified. Finally, the target network pharmacology approach was applied to explore the potential targets and possible mechanisms of the absorbed components from TCM. The reliability and availability of this approach was demonstrated using Tongfengding capsule (TFDC) as an example of herbal medicine. A total of 141 compounds were detected and identified in TFDC, and among them, 64 components were absorbed into the plasma. Then, a total of 35 absorbed bioactive components and 50 related targets shared commonly by compounds and gout were integrated via target network pharmacology analysis. Ultimately, the effects of the absorbed components on metabolism pathways were verified by experiments. These results demonstrated that this original method may provide a practical tool for screening bioactive compounds from TCM treating particular diseases. Furthermore, it also can clarify the potential mechanism of action of TCM and rationalize the application of TFDC as an effective herbal therapy for gout.

Traceability of Geographical Origin in Gentiana straminea by UPLC-Q Exactive Mass and Multivariate Analyses

The root of Gentiana straminea Maxim. (Gentianaceae), is officially listed as "Qin-Jiao" in the Chinese Pharmacopoeia for the treatment of rheumatic arthritis, icteric hepatitis, constipation, pain, and hypertension. To establish the geographical origin traceability in G. straminea, its chemical profiles were determined by a UPLC-Q exactive mass spectrometer, from which 43 compounds were identified by comparing retention times and mass spectrometry. Meanwhile, a pair of isomers (loganin and secologanol) was identified by mass spectrometry based on their fragmentation pathway. A total of 42 samples from difference habitats were determined by an UPLC-Q exactive mass spectrometer and the data were assayed with multivariate statistical analysis. Eight characteristic compounds were identified to determine the geographical origin of the herb. To estimate the key characteristic markers associated with pharmacological function, the inhibiting activities of nitric oxide (NO) production in lipopolysaccharide (LPS)-induced macrophages were examined. This finding is crucial in realizing the determination of botanical origin and evaluating the quality of G. straminea.

Botany, traditional use, phytochemistry, pharmacology, quality control, and authentication of Radix Gentianae Macrophyllae-A traditional medicine: A review

BACKGROUND

Radix Gentianae Macrophyllae, commonly known as Qinjiao (in Chinese), is dried roots of medicinal plants that belong to Gentianaceae family and Gentiana genus. It has medically been used for the treatment of various diseases such as arthritis, stroke, facial paralysis, and scapulohumeral periarthritis in China since ancient times.

PURPOSE

The aim of this paper is to provide a comprehensive and constructive overview of Qinjiao mainly containing Gentiana macrophylla Pall., Gentiana straminea Maxim., Gentiana crasicaulis Duthie ex Burk., and Gentiana daurica Fisch. in botany, traditional use, phytochemicals, pharmacology (biological activities and pharmacokinetics), quality control, and authentication according to the up-to-date data of available scientific literatures.

MATERIALS AND METHODS

All information regarding these four plants was collected from various academic search engines for example Google, Google Scholar, Web of Science, SciFinder, Pubmed, CNKI, and Wanfang. Additional information was obtained from botanical books, Chinese classic texts, and medical monographs.

RESULTS

So far 166 compounds have been isolated and identified from Qinjiao plants together with Gentiana tibetica King ex Hook. f., Gentiana siphonantha Maxim., Gentiana officinalis H. Smith, and Gentiana waltonii Burk. Their constituents are mainly classified into iridoid glycosides, triterpenes, flavones, sterols, benzene derivatives, etc. The pharmacological studies demonstrate that Qinjiao plants display a wide range of bioactivities e.g. anti-inflammatory, anti-oxidant, hepato-protective, cardio- and neuro-protective, insecticidal, and anti-influenza effects. The conventional quality control is performed by determination of the concentration of some compounds, e.g., gentiopicroside, or establishment of the fingerprint. In addition to seed propagation, tissue culture technology has been used to address the limited supplies and guarantee the sustainable development of Qinjiao in the experimental scale.

CONCLUSIONS

Although the identification of compounds from Qinjiao and demonstration of medicinal uses in vitro and in vivo have been carried out, various other studies on these plants should deserve our more attention. More efforts should be concentrated on the underlying mechanisms of their beneficial bioactivities. The proper toxic evaluation is indispensable to guarantee the safety, efficacy, and eligibility for medical use. To sum up, the summarized achievements could highlight the importance of Qinjiao and provide a solid foundation for scientists not only to further exploit the therapeutic potentials, but also possibly develop novel drugs in the subsequent research.

Analytical Methods of Phytochemicals from the Genus Gentiana

The genus Gentiana comprises approximately 400 species. Many species have a wide range of pharmacological activities and have been used therapeutically for thousands of years. To provide comprehensive guidance, utilization and quality control of Gentiana species, this review presents updated information concerning the recent application and progress of chemical analysis including phytochemical analysis, sample preparation and chemometrics. Detailed and comprehensive data including number of analytes, extraction/separation methods, analytical techniques and chemometrics are shown as corresponding tables. These data illustrate that the development of newly discovered compounds and therapeutic uses, understanding of the structure-activity relationship and establishment of harmonious and effective medicinal herb standards are the direction of advancement in future research.

Iridoid glycosides from the Genus Gentiana (Gentianaceae) and their Chemotaxonomic Sense

The genus Gentiana is one of the largest genera in the Gentianaceae family. Many Gentiana species have been scientifically investigated for their chemical constituents and chemotaxonomic sense. To date, more than 500 chemical compounds were isolated from Gentiana plant. Several researchers have reviewed the secondary metabolites and their bioactivities of Gentiana plants. However, a survey on iridoid glycosides and their chemotaxonomic sense of the genus Gentiana are unavailable. Iridoid glycosides are the major chemicals isolated from Gentiana spp., which serve as potential chemotaxonomic markers to differentiate Gentiana species. Herein, the review systematically summarizes the scaffolds of the iridoids reported according to the biosynthetic pathway of natural iridoid glycosides. Furthermore, the taxonomy of Gentiana and chemotaxonomic sense of iridoid glycosides in the genus Gentiana were surveyed.

Chemical constituents of Swertia mussotii and their anti-hepatitis B virus activity

Three new secoiridoid aglycones of (-)-swermusic acid A (1) and B (3), and (-)-swerimuslatone A (2), and four new secoiridoid glycosides of 6'-O-formylsweroside (4), 6'-O-formylgentiopicroside (5), 6'-O-acetylamarogentin (6) and 6'-O-acetylamaronitidin (7), along with 40 known compounds (8-47) were isolated from Swertia mussotii. Their structures were elucidated on the basis of extensive spectroscopic analyses including MS, IR, UV, 1D- and 2D-NMR. Forty-five compounds from S. mussotii were evaluated for their anti-HBV activity on the HepG 2.2.15 cell line in vitro inhibiting the secretions of HBsAg and HBeAg, as well as HBV DNA replication. Six of the nine phenols 26-29, 31 and 32 exhibited activities inhibiting HBsAg and HBeAg secretion with IC50 values from 0.23 to 5.18mM, and HBV DNA replication with IC50 values from <0.06 to 2.62mM. Moreover, isooriention (45) displayed significant anti-HBV activities against secretions of HBsAg and HBeAg with IC50 value of 0.79 and 1.12mM, as well as HBV DNA replication with IC50 value of 0.02mM.

Anti-inflammatory compounds of "Qin-Jiao", the roots of Gentiana dahurica (Gentianaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

"Qin-Jiao" is a well-known traditional Chinese medicinal (TCM) herb having been used generally for fighting rheumatoid arthritis (RA) since ancient times. The root of Gentiana dahurica Fisch (Gentianaceae) is one of the four officially validated "Qin-Jiao" as listed in the Chinese Pharmacopoeia. In addition, it is a common Tibetan medicinal herb used for the treatment of tonsillitis, urticaria, and RA, while the flowers have been used as a Mongolian herb for curing cough sore throat and eliminating the phlegm due to its anti-inflammatory effect.

AIM OF THE STUDY

The aim of the study was to characterize the anti-inflammatory compounds in "Qin-Jiao", on the basis of detailed investigation on not only the phytochemical study of Gentiana dahurica, but also the bioactive evaluation on compounds obtained presently and previously from different "Qin-Jiao" origins and Gentiana species.

MATERIALS AND METHODS

The ethanol extract of air-dried roots of Gentiana dahurica was suspended into H2O and extracted with EtOAc and n-BuOH, successively. Repeated column chromatography (CC) and semi-preparative HPLC were carried out on each of the fractions. The isolated compounds were determined by detailed spectroscopic analysis and acidic hydrolysis. Anti-inflammatory activities of 18 isolates, together with 12 typical compounds obtained previously by our group from the other "Qin-Jiao" origins (Gentiana crassicaulis, Gentiana straminea) and Gentiana rigescens, were tested by inhibitory effects on LPS-induced NO production in macrophage RAW264.7 cells and TPA-induced cyclooxygenases-2 and -1 (COXs-2/1) production on zebrafish model.

RESULTS

A new lignan glycoside (1) was identified, together with 20 known compounds, including 10 iridoid glycosides (2-11), three steroids (12-14), four lignans (15-18), one phenylpropanoid (19) and two triterpenes (20-21). Anti-inflammatory bioassay showed that only compound 21 displayed potential inhibitory effect on NO production (IC50=16.85 μM), while 20 tested compounds had inhibitory activities on COXs-2/1. Among them, the triterpenoid 21 was the most active compound with an inhibitory value of 78% at a concentration of 30 μM. All the tested compounds showed no cytotoxicity on five human cancer cell lines (40μM) and zebrafish (30 μM), except for 21 displaying weak cytotoxicity on human myeloid leukemia HL-60 (IC50=16.43 μM).

CONCLUSION

Most of compounds particularly iridoid glycosides from "Qin-Jiao" display potential inhibitory effect on COXs-2/1. The results support the historical importance of the well-known TCM herb, "Qin-Jiao", having been commonly used for fighting RA. As major components, the bioactive iridoid glycosides should play important role in the anti-inflammatory effect of "Qin-Jiao". Although further research will be required to evaluate the selective activities of the COXs-2/1 inhibitors, this work validates the medicinal use of "Qin-Jiao" and provides information for different "Qin-Jiao" origins having different treating effects on RA.

Chemical Profile, Radical Scavenging and Cytotoxic Activity of Yellow Gentian Leaves (Genitaneae Luteae Folium) Grown in Northern Regions of Montenegro

LC-ESI-MS and HPLC were used for the identification of the constituents from G. lutea leaves collected at different localities, as well as for quantification of the main compounds. Seven secoiridoids, five C-glucoflavones and three xanthones, were identified. Swertiamarin derivatives, namely eustomorusside (2), eustomoside (3) and septemfidoside (5), were detected in G. lutea for the first time. Concentrations of five constituents (swertiamarin, gentiopicrin, isovitexin, mangiferin and isogentisin) were determined. The relationship between concentrations of γ-pyrones and altitude was observed with statistically significant correlation ( r = 0.94). The extracts were also evaluated for their content of total phenolics, and antiradical and cytotoxic activities. The total phenolics content ranged from 7.7 to 12.7 mg GAE/g, and the IC50 values for DPPH radical scavenging activity varied between 0.45 to 2.02 mg/mL. The leaf extract exhibited moderate cytotoxic effects toward HeLa cells with an IC50 value of 41.1 μg/mL, while gentiopicrin, mangiferin and isogentisin exerted strong activity against HeLa cells, with IC50 values ranging from 5.7 to 8.8 μg/mL. The results confirm the traditional usage of G. lutea leaves and also suggest their possible utilization as hepatoprotective, hypoglycemic and anti-inflammatory agents.

Triterpenoids

This review covers the isolation and structure determination of triterpenoids, including squalene derivatives, protostanes, lanostanes, holostanes, cycloartanes, dammaranes, euphanes, tirucallanes, tetranortriterpenoids, quassinoids, lupanes, oleananes, friedelanes, ursanes, hopanes, serratanes and saponins; 305 references are cited.

Triterpenoids and steroids from the fruits of Melia toosendan and their cytotoxic effects on two human cancer cell lines

Ten new triterpenoids, named meliasenins I-R (1-10), one new steroid (11), and 11 related known compounds (12-22) were isolated from fruits of Melia toosendan. The structures of the new compounds were established on the basis of spectroscopic methods, including 2D NMR techniques and mass spectrometry. The relative configuration of 1, (20R*,23E)-25-hydroperoxyeupha-7,23-diene-3β,16β-diol (meliasenin I), was confirmed by single-crystal X-ray diffraction analysis. All isolated triterpenoids (1-10, 12-15) and two steroids (11, 20) were tested for their cytotoxicity against U20S human osteosarcoma and MCF-7 human breast cancer cells using the MTT assay, and some of them were significantly cytotoxic (IC(50) <10 μg/mL). The insecticidal properties of compounds 1-15 and 20 were also briefly evaluated.