Anti-hepatitis B virus active secoiridoids from Swertia kouitchensis

Three new secoiridoids, swertiakoulactone (1) and swertiakosides A and B (2 and 3), were isolated from Swertia kouitchensis. Their structures were elucidated by comprehensive spectroscopic analyses including MS, IR, 1D and 2D NMR data. By the anti-hepatitis B virus (HBV) assay on Hep G 2.2.15 cells line in vitro, compound 1 showed moderate activities inhibiting the HBsAg secretion (IC50 = 1.10 mM, SI = 4.39) and HBV DNA replication (IC50 = 1.16 mM, SI = 4.12).

Study on the effect and mechanism of Swertia mussotii Franch. in the treatment of primary biliary cholangitis based on bioinformatics and in vitro experiments

Background:Primary biliary cholangitis(PBC)is a chronic biliary autoimmune liver disease characterized by intrahepatic cholestasis.Swertia mussotii Franch.(SMF)is a Tibetan medicine with hepatoprotective and anti-inflammatory activities.In this study,the therapeutic effect and potential mechanisms of SMF on PBC were investigated by bioinformatics analysis and in vitro experimental validation,with the aim of promoting the progress of SMF and PBC research.Methods:We first explored the therapeutic effects and key targets of SMF on PBC using a network pharmacology approach,further screened the core targets using the GSE79850 dataset,and finally validated the results using molecular docking techniques and in vitro experiments.Results:By bioinformatics analysis,we identified core targets of SMF for PBC treatment(STAT3,JAK2,TNF-α,and IL-1β)and important signaling pathways:JAK-STAT,TNF,and PI3K-AKT.The molecular docking results showed that the significant components of SMF had good binding properties to the core targets.In vitro experiments showed that SMF extracts improved the extent of epithelial-mesenchymal transition in human intrahepatic biliary epithelial cells and had a significant reversal effect on epithelial-mesenchymal transition process markers and potential targets in PBC.Conclusion:SMF may exert its therapeutic effects on PBC by acting on important targets such as STAT3,JAK2,TNF-α,IL-1β,Vimentin,and E-cadherin and the pathways in which they are involved.

New Xanthones from Swertia decora

From the CHCl3 part of Swertia decora Franch., a traditional medicinal herb of China, two new xanthones, swertiadecoraxanthone-I and swertiadecoraxanthone-II along with four known compounds have been isolated and identified on the basis of spectral analysis and chemical evidence.

Two Bisxanthone C-glycosides from Swertia calycina Franch

首次从抱萼獐牙菜全草中分得两个双酮碳式化合物。经理化常数和光谱分析鉴定为紫药双酮甙；3－O－去甲禁药双酮甙。

Isolation and Crystal Structure of Xanthones from Swertia Chirayita

In order to study the relationship between biological and pharmacological activities with their structures, a series of tri- and tetra-oxygenated xanthones including 1-hydroxyl-2,3,4,7- tetramethoxy xanthone 1, 1-hydroxyl-2,3,4,5-tetramethoxyl xanthone 2, 1-hydroxyl-3,5-dimethoxy- xanthone 3, 1,8-dihydroxyl-3,5-dimethoxyl xanthone 4 and 1,5,8-trihydroxyl-3-methoxy xanthone 5 have been isolated from Swertia chirayita. Their structures were established on the basis of spectral and chemical evidences. The crystal structure of 5 was also investigated by single-crystal X-ray diffraction analysis. It crystallizes in the triclinic system, space group P?with a = 7.1540(10), b = 7.520(2), c = 10.671(2) , V = 562.7(2) 3 , α = 86.50(3), β = 80.06(3) , γ = 85.00(3), Z = 2, Dc = 1.618 g/m3, R = 0.0405, wR = 0.1028 and F(000) = 284. The molecular structure of 5 is nearly planar and four substituents are much closer to the plane. Compound 5 contains three intermolecular hydro- gen bonds. A recent study shows that phenolic hydroxyls in xanthones are the main active groups capable of scavenging OH and O2.

Minor secoiridoid aglycones from the low-polarity part of the traditional Chinese herb: Swertia mileensis

Eleven new secoiridoid aglycones involving unusual C9-skeleton:swerimilegenins A-F(1-6);bis-C9-skeleton:swerimilegenin G(7);and C_(10)-skeleton:swerimilegenins H−K(8−11),as well as six known ones,were isolated from the low-polarity part of the traditional Chinese herb medicine Swertia mileensis.Their structures were determined by extensive spectroscopic data and X-ray diffraction.Biogenetically,swerimilegenin A(1)belonged to 10-nor-secoiridoid,and swerimilegenins B-F(2-6)were 1-nor-secoiridoids.Erythrocentaurin(12)and gentiogenal(15)showed moderate anti-HBV activity on HepG 2.2.15 cell line in vitro.

A New Monoterpene Glycoside from Swertia punicea

A new monoterpene glycoside, 2,6-dimethyl-2E,6E-octadienoic acid 1,6'-lactone 8-beta-D-glucopyranoside, was isolated from Swertia punicea, accompanying with six known compounds 1-O-primeverosyl-3,7-dimethoxy-8-hydroxyxanthone, 1-O-primeverosyl-3,7,8-tri-methoxyxan-thone, epi-eustomoside, 1-hydroxy-3,7,8-trimethoxyxanthone, 1,8-dihydroxy-3,7-dimethoxy xanthone and isovitexine. Their structures were elucidated based on spectral evidence.

丽江獐牙菜(Swertia delavayi)化学成分研究

目的:研究民族药丽江獐牙菜(Swertiadelavayi)的化学成分,寻找活性物质。方法:用系统溶剂提取,常规的硅胶柱层析和薄层色谱进行分离纯化,根据化合物的物理、化学性质和波谱特征鉴定其结构。结果:从丽江獐牙菜的脂溶性部分分离得到6个化合物,其中3个分别鉴定为齐墩果酸、1,8-二羟基-3,7-二甲氧基酮和1,7,8-三羟基-3-甲氧基酮,另3个结构正在鉴定中。结论:所有化合物均为首次从该植物中得到。

Two New Xanthone Glycosides from Swertia Tetraptera

Two new xanthone glycosides, tetraswerosides A and B, were isolated from the whole plant of Swertia tertraptera. Their structures were determined as 3-O-beta -D-glucopyranosyl-1-hydroxy-4,7-dimethoxyxanthone and 3-O-[beta -D-xylopyranosyl-(1-->6)-beta -D-glucopyranosyl]-1- hydroxy-4,7-dimethoxyxanthone by spectroscopic methods.

An Efficient Method for Plant Regeneration from Calli of <i>Swertia mussotii</i>, an Endangered Medicinal Herb

Swertia mussotii Franch is an endangered medicinal plant in the Qinghai-Tibet Plateau. Its regeneration from callus culture is very difficult. In this study, an efficient method for plant regeneration was developed from its calli. The calli derived from young stem explants of S. mussotii were cultured at two types of temperature treatments to test their efficiency of shoot regeneration. When the calli were cultured at variable temperature (VT, 20℃ during the day and 10℃ at night) treatment, the adventitious shoots were formed at each combination tested. However, that did not occur when the calli were cultured at constant temperature (CT, 25℃) treatment. The best response (53.7%) of plantlet regeneration was obtained on Murashige and Skoog (MS) medium containing 3 mg·l-1 6-benzylaminopurine with 0.5 mg·l-1 α-naphthaleneacetic acid in the VT treatment. The regenerated plantlets were rooted on half-strength MS medium without growth regulators. They flowered in the following subculture. The results indicate that the treatment of day-night temperature difference is a critical factor to callus differentiation in S. mussotii. This protocol can be used for conservation as well as mass propagation of this medicinal plant.

Utilization of Swertia chirayita Plant Extracts for Management of Diabetes and Associated Disorders: Present Status, Future Prospects and Limitations

Diabetes mellitus is referred as common metabolic abnormalities characterized as hyperglycemia,mainly caused due to insufficient production of insulin at cellular level or/and defects in insulin action.Such an endocrine disorder is responsible for serious health problems and its worldwide prevalence is rapidly increasing.Common management of diabetes by oral administration of drugs without creating any side effects is still considered a challenging task and increasing cost of con-ventional medicine in developing countries is another matter of concern.To address these issues,traditional preparations of herbal plant extracts in the form of medicines already gained immense attention.Swertia chirayita is one among such plants which is known for its hypoglycemic potential.Numerous chemical constituents with promising pharmacological properties have been identified from such plant extracts but still,such compounds have not been well characterized,specifically against human application.Hence,more research efforts are necessitated to understand exact mechanism of such compounds and to develop overall safety of such plant formulations.Present review clearly represents antidiabetic properties of Swertia chirayita extract,strategies to be taken to strengthen its safety application on humans and biotechnological interventions that ensure conservation of such endangered species to promote its future application in modern medicine.

A Novel Monoterpene Glycoside from Swertia mileensis

A novel monoterpene glycoside, mileenside, was isolated from Swertia mileensis by repeated normal and reverse phase silica gel chromatography and its structure was elucidated mainly based on spectral evidence.

A new monosaccharide from Swertia punicea Hemsl

A new compound named 1-hydrate, 3-deoxy-α-D-tagatofuranose was isolated from Swertia punicea Hemsl. The structure of compound was determined by 1D and 2D NMR, HRESIMS techniques.

Antioxidants, anti-proliferative, anti-inflammatory, anti-diabetic and anti-microbial effects of isolated compounds from Swertia corymbosa (Grieb.) Wight ex C.B. Clark – An in vitro approach

The present study,antioxidant,enzyme inhibitory,anti-inflammatory and antimicrobial activity of isolated compounds such as Decussatin(1),Gentiacaulein(2),Swertianin(3),1,8-dihydroxy-2,6-dimethoxy xanthone(methylswertianin)(4)8-hydroxy-1,2,4,6-tetramethoxyxanthone(5)and 1,2-dihydroxy-6-methoxyxanthone-8-O--d-xylopyranosyl(6)were investigated using an in vitro model.Results of antioxidant studies revealed that the compound 6 possessed an efficient 2,2-diphenyl-1-picryl-hydrazyl(DPPH•)(IC5007.19±4.56μmol/mL),2,2-azinobis(3-ethylbenzothiozoline-6-sulfonic acid)(ABTS•^+)(42.62±0.25 mmol/L TE/g),superoxide(57.89±3.45μmol/mL),nitric oxide(18.45±1.23μmol/mL)and hydroxyl(12.13±2.76μmol/mL)radical scavenging activities,ferric reducing antioxidant power(14.76±0.10 molar Fe(II)/g),metal chelating(213.85±27.18 mg EDTA/g)ability.Compounds 6 and 3 exhibited significant anti-proliferative activity.Compound 6 displayed strongest antibacterial activity against Streptococcus pneumoniae and Escherichia coli with MIC value of 3.90μg/mL and 21.21±0.25 and 20.27±0.11 mm zone of inhibition at 25μg/mL concentration respectively.In the membrane stabilization and protein denaturation test 3 was the most potent with an IC50 value of 12.57,18.75μmol/mL respectively.

Chemical constituents isolated from the aerial parts of Swertia pseudochinensis and their potential neuroprotective effects

Objective:Swertia pseudochinensis,an annual herb of the genus Swertia in the family Gentianaceae.Some constituents and extracts from the Swertia genus have been recently reported to possess neuroprotective effects,suggesting their potential utility in the prevention and treatment of Parkinson disease(PD).The aim of this work is to identify the chemical constituents and evaluate the potential biological activists of Swertia pseudochinensis.Methods:The phytochemicals from the aerial parts of S.pseudochinensis were isolated and purified by silica gel,Sephadex LH-20 gel,semi-preparative high-performance liquid chromatography,and identified by the spectroscopic methods.All compounds were evaluated for their potential neuroprotective effects against 1-methyl-4-phenylpyridinium-induced apoptosis in the SH-SY5Y human neuroblastoma cell line using the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay.Then,we performed an enrichment analysis using the Database for Annotation,Visualization,and Integrated Discovery and investigated the mechanisms by which bellidifolin regulates neurodegenerative disease.Results:Two new anthraquinone,1,5,6-trimethoxy-2-hydroxy-3-methy-anthraquinone(1)and 1,5,6,8-tetramethoxy-2-hydroxy-3-methyanthraquinone(2),together with nine known including 7-O-b-d-glucopyranosyl-1,8-dihydroxy-3-methoxyxanthone(3),gentisin(4),swertianolin(5),bellidifolin(6),gentiacaulein(7),norswertianolin(8),5-O-b-d-glucopyranosyl-1,3,8-trihydroxyapatone(9),1-hydroxy-3,5,8-trimethoxyxanthone(10),and aurantio-obtusin(11),were isolated and compounds 6–8 and 10 exhibited neuroprotective effects at a concentration of 50mmol/L.Among them,bellidifolin showed significant protective activity,and might have potential as a neuroprotective agent for the treatment of PD,possibly by acting on oxidative damage and reactive oxygen species.Conclusions:These findings indicate that further research on the genus Swertia and its bioactive constituents toward neurodegenerative disorders could be extremely rewarding.

Determination of Ursolic Acid a Biomarker in Different Swertia Species through High Performance Thin Layer Chromatography

A simple highly precise method has been established for the determination of ursolic acid in three species of Swertia viz. S. angustifolia, S. paniculata, and S. alata. The assay combines identification and quantification of the analyte on silica gel 60GF254 HPTLC plates with visualization under UV light and scanning at 510 nm.

Neuroprotective effects of xanthone extract from Swertia punicea Hemsl against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-induced mouse model of Parkinson's disease

As a widely used traditional Chinese medicine （TCM）, Swertia punicea Hemsl has exhibited effects on anti-hepatitis B virus （HBV）, liver protection, hypoglycemic activity and cholecystitis. In this study, we confirmed that xanthone extract from Swertia punicea Hemsl （XSPH） improved the motor deficit, increased the levels of striatal dopamine （DA） and homovanilic acid （HVA）, and alleviated the loss of tyrosine hydroxylase （TH）-positive neurons located in substantia nigra pars compacta （SNpc） in MPTP-induced mouse model of Parkinson＇s disease （PD）. In conclusion, the present results indicated that XSPH offered neuroprotective effects against the neurotoxicity of MPTP and it might be a potential treatment for PD.

A New Secoiridoid Glycoside from Swertia cincta

Objective To study the chemical constituents of Swertia cincta. Methods Preparative liquid chromatography was employed. The structures of the compounds were elucidated by spectroscopic analysis. isolated from S. cincta and identified as Results Three secoiridoid glycosides were 8-methoxyl-eustomorusside （1）, secoiridoids eustomorusside （2）, and eustomoside （3）. Conclusion Compound 1 is a new secoiridoid glycoside. Compounds 2 and 3 are isolated from this plant for the first time.

Predictive distribution modeling of Swertia bimaculata in Darjeeling-Sikkim Eastern Himalaya using MaxEnt: current and future scenarios

Background:As global temperatures continue to rise,species distribution modeling is a suitable tool for identifying rare and endangered species most at risk of extinction,along with tracking shifting geographical range.Methods:The present study investigates the potential distribution of Swertia bimaculata in the Darjeeling-Sikkim region of Eastern Himalaya in current and future climate scenarios of GFDL-CM3(Geophysical Fluid Dynamics Laboratory-Climate Model 3)for the year 2050 and year 2070 through MaxEnt presence data modeling.Two sets of variables were used for modeling current scenario.The models were evaluated using AUC(area under the curve)values and TSS(true skill statistic).Results:Habitat assessment of the species shows low and sporadic distribution within the study area.A significant decrease is observed in the possible range of the species in the future climate scenario with the habitat decreasing from 869.48 to 0 km^(2).Resultant maps from the modeling process show significant upward shifting of the species range along the altitudinal gradient.Still,results should be taken with caution given the low number of occurrences used in the modeling.Conclusions:The results thus highlight the vulnerability of the species towards extinction in the near future.

A New Compound from Swertia cincta

Objective To study the chemical constituents from the whole plant of Swertia cincta.Methods The chemical constituents were purified by chromatographic methods such as silica gel column and Sephadex LH-20. The structures of these compounds were elucidated by MS, IR, and NMR analyses. Results Two compounds were isolated from S. cincta. Conclusion Compound 1 is a new compound named swercinctlactone A. Compound 2 is identified as（±）-gentiolactone and its configuration is confirmed by single crystal X-ray diffraction and optical specific rotation.