Guidongnins I-J: Two New 6,7-seco-7,20-Olide-ent-kaurene Diterpenes with Unusual Structures from Isodon rubescens.

Two undescribed ent-kaurene diterpenes, named guidongnins I (1) and J (2), were isolated from the medicinal plant Isodon rubescens. Compound 1 was determined to contain an unprecedented 23 carbons in the skeleton by bearing an extra isopropyl group at C-17 out of the diterpenoid parent structure, and compound 2 was the first example of 6,7-seco-7,20-olide-ent-kaurenes with two fused-tetrahydrofuran rings formed between C-6 and C-19/C-20 through oxygen bridges. Their structures, including their absolute configurations, were determined using the analyses of the spectroscopic and X-ray diffraction data. Guidongnins I (1) and J (2) were assessed for their anti-cancer activities against the growth of various cancer cell lines, and 2 displayed cytotoxic potency against HepG2 at IC50 27.14 ± 3.43 µM.

Triterpenoid and Coumarin Isolated from Astilbe grandis with Anti-Inflammatory Effects through Inhibiting the NF-κB Pathway in LPS-Induced RAW264.7 Cells.

The roots of Astilbe grandis, known as "Ma sang gou bang", are used as a Miao traditional medicine with anti-inflammatory and analgesic properties. However, the active components and mechanism of action of this plant remain mostly uncharacterized. The aim of this study was to identify its active components and verify their pharmacological activity. The extract of A. grandis root was separated using various chromatographic methods. As a result, we obtained one novel triterpenoid, named astigranlactone (1), which has an unusual lactone moiety formed between C-7 and C-27. Additionally, a known coumarin compound, 11-O-galloyl bergenin (2) was isolated from this plant. The structures of these two compounds were elucidated by extensive NMR experiments in conjunction with HR-ESI-MS data. To the best of our knowledge, both compounds were isolated from this species for the first time. Moreover, we tested the anti-inflammation effect of the two compounds by establishing a cellular inflammation model induced by LPS in RAW264.7 cells. The effect of different concentrations of these compounds on the activity of RAW264.7 cells was assessed using a CCK8 assay. The levels of nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1ß (IL-1ß) in the supernatant of each group were evaluated using the Griess method and an enzyme-linked immunosorbent assay (ELISA). Western blot and quantitative real-time PCR (qRT-RCR) were used to measure the levels of cyclooxygenase 2 (COX-2) and nitric oxide synthase (iNOS) gene expression. Our findings revealed that these two compounds inhibited the high levels of NO, TNF-α, IL-6, IL-1ß, COX-2, and iNOS (induced by LPS). Mechanistic studies demonstrated that these two compounds reduced the activation of the nuclear transcription factor-B (NF-κB) signaling pathway by inhibiting the phosphorylation of p65. Therefore, our study indicates that compounds 1 and 2 can exert a definite anti-inflammatory effect by inhibiting the NF-κB signaling pathway.

Bioactive isopimarane and 3,4-seco isopimarane diterpenoids from Isodon amethystoides.

Isodon amethystoides (Lamiaceae) is a popular plant in folk medicine in the southern provinces of China. Our phytochemical investigation of the twigs and leaves of this plant led to the discovery of five new diterpenoids with isopimarane and 3,4-seco isopimarane scaffolds [isoamethinols A-E (1-5)], along with the known compound 3,4-seco isopimara-4(18),7,15-triene-3-oic acid methylester (6). The chemical structures of these compounds, including the absolute configurations of the new diterpenoids, were determined by comprehensive spectroscopic analyses and single crystal X-ray diffraction measurements. These compounds were evaluated for their biological activities against a panel of human cancer cell lines, gram-positive bacterial strains and HIV. Notably, the 3,4-seco-isopimarane isoamethinol D (4) showed toxicity to the cervical Hela cancer (Hela) cells with an IC50 value of 27.21 µM and the lung (A549) cancer cells with an IC50 value of 21.47 µM. Compound 4 also exhibited mild antimicrobial activity against the oral bacterial strain Streptococcus mutans. These findings suggested that the diterpenoids with a 3,4-seco-isopimarane diterpenoids isolated from I. amethystoides could provide a novel structure scaffold for the discovery of anticancer and antimicrobial compounds.

3,4-Seco-Isopimarane Diterpenes from the Twigs and Leaves of Isodon Flavidus.

Three isopimarane diterpenes [fladins B (1), C (2), and D (3)] were isolated from the twigs and leaves of Chinese folk medicine, Isodon flavidus. The chemical structures were determined by the analysis of the comprehensive spectroscopic data, and the absolute configuration was confirmed by X-ray crystallographic analysis. The structures of 1-3 were formed from isopimaranes through the rearrangement of ring A by the bond break at C-3 and C-4 to form a new δ-lactone ring system between C-3 and C-9. This structure type represents the first discovery of a natural isopimarane diterpene with an unusual lactone moiety at C-9 and C-10. In the crystal of 1, molecules are linked to each other by intermolecular O-H···O bonds, forming chains along the b axis. Compounds 1-3 were evaluated for their bioactivities against different diseases. None of these compounds displayed cytotoxic activities against HCT116 and A549 cancer cell lines, antifungal activities against Trichophyton rubrum and T. mentagrophytes, or antiviral activities against HIV entry at 20 µg/mL (62.9-66.7) µM. Compounds 1 and 3 did not show antiviral activities against Ebola entry at 20 µg/mL either; only 2 was found to show an 81% inhibitory effect against Ebola entry activity at 20 µg/mL (66.7 µM). The bioactivity evidence suggested that this type of compound could be a valuable antiviral lead for further structure modification to improve the antiviral potential.

Curcumin, novel application in reversing myocardial fibrosis in the treatment for atrial fibrillation from the perspective of transcriptomics in rat model.

In order to explore the possible mechanism of curcumin in the treatment of AF, we focused on the myocardial fibrosis in the pathogenesis of atrial fibrillation to explore whether curcumin could play a role in the treatment of AF by reducing myocardial fibrosis.Rats were given daily gavage of saline (control and AF groups) or curcumin (4 mL/kg, concentration: 50 mg/mL, curcumin groups) during days 4-28. The rat model of AF was induced by Ach - CaCl2, and evaluate the therapeutic effect of curcumin on the duration of AF rhythm, the degree of myocardial fibrosis and the secretion of inflammatory factors in serum. RNA-seq to explore the possible mechanism of curcumin alleviating myocardial fibrosis of AF. curcumin significantly inhibits the duration of AF and reduces the degree of left atrial fibrosis. ELISA results showed curcumin could significantly reduce the secretion of IL-17A, IL-1ß, IL -6 and TGF-ß1. Bioinformatics analyses revealed that the IL-17 signaling pathway are involved in the therapeutic mechanism of curcumin. Furthermore, The genes encoding Col1a1, Fasn, Pck1, Bmp10, IL33 and Figf were pivotal and possible key genes for the therapeutic mechanisms of curcumin.Curcumin can reduce the degree of left atrial fibrosis of AF and the secretion of inflammatory factors. The therapeutic effect of curcumin on AF was attributed to its effect on the IL-17 signaling pathway. Besides, COL1A1, FASN, PCK1, BMP10, IL33 and FIGF were the pivotal genes associated with mechanisms of action of curcumin on AF.

Rubesanolides F and G: Two Novel Lactone-Type Norditerpenoids from Isodon rubescens.

A phytochemical investigation of the leaves of the medicinal plant Isodon rubescens led to the isolation of the two new degraded abietane lactone diterpenoids rubesanolides F (1) and G (2). Their structures were elucidated based on the analyses of the HRESIMS and 1D/2D NMR spectral data, and their absolute configurations were determined by ECD spectrum calculations and X-ray single crystal diffraction methods. Compounds 1 and 2, with a unique γ-lactone subgroup between C-8 and C-20, were found to form a carbonyl carbon at C-13 by removal of the isopropyl group in an abietane diterpene skeleton. Rubesanolide G (2) is a rare case of abietane that possesses a cis-fused configuration between rings B and C. The two isolates were evaluated for their biological activities against two cancer cell lines (A549 and HL60), three fungal strains (Candida alba, Aspergillus niger and Rhizopus nigricans) and three bacterial strains (Escherichia coli, Staphylococcus aureus and Bacillus subtilis).

Ethyl acetate fraction from Nymphaea hybrida Peck modulates inflammatory responses in LPS-stimulated RAW 264.7 cells and acute inflammation murine models.

ETHNOPHARMACOLOGICAL RELEVANCE: Nymphaea hybrida Peck is used as a traditional medicinal herb for treating pain and inflammatory diseases, and known for its ornamental value and as a hot drink. However, the effects of N. hybrida polar fractions on lipopolysaccharide (LPS)-induced in vitro inflammation model and acute inflammation murine models have yet to be evaluated. AIM OF THE STUDY: The aim of this study was to elucidate the anti-inflammatory effects of N. hybrida ethanol extract (NHE) and its polar fractions: petroleum ether (PE), methylene chloride (MC), ethyl acetate (EA), methanol (ME), and water (WA). The underlying molecular mechanisms of active fraction in LPS-stimulated RAW 264.7 murine macrophages were further investigated. MATERIAL AND METHODS: Fractions with potential anti-inflammatory effects were screened using direct nitric oxide (NO) radical scavenging and cyclooxygenase (COX)-2 inhibition assays in vitro. The anti-inflammatory properties of potential fraction were evaluated in LPS-stimulated RAW264.7 cells, xylene-induced ear edema, carrageenan-induced paw edema and xylene-induced Evans blue exudation of acute inflammation murine models. The regulation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways were investigated using western blotting and immunofluorescence. RESULTS: Compared to other polar fractions, NHE-EA displayed higher phenol and flavonoid content, and exerted greater activity in direct NO radical scavenging and COX-2 inhibition assay in vitro. NHE-EA markedly decreased the levels of inflammatory mediators, NO and prostaglandin E2 (PGE2), by suppressing the over-expression of inducible nitric oxide synthase (iNOS) and COX-2 in LPS-stimulated RAW264.7 cells. The NHE-EA fraction dose-dependently alleviated over-elevation of LPS-associated intracellular calcium and decreased the abnormal secretion of pro-inflammatory cytokines, tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), IL-6, and interferon-γ (IFN-γ). The combination with NHE-EA effectively attenuated the activation and nuclear translocation of NF-κB p65, and the phosphorylation of extracellular signal-regulated kinases (ERK), c-Jun N-terminal kinases (JNK), and p38 kinases of MAPK pathways. NHE-EA could significantly ameliorate the degree of swelling of the mice ear and paw, the skin exudation of Evans blue and the excessive secretion of inflammatory cytokines. CONCLUSION: Our results demonstrated that NHE-EA was the most active polar fraction of N. hybrida extracts. It inhibited the LPS-associated inflammatory response by blocking the activation of NF-κB and MAPKs pathways in RAW264.7 cells. It also effectively alleviated the inflammatory response of acute inflammation. These results indicated the role of NHE-EA as adjuvants and their potential role in alternative strategy for the treatment of inflammatory diseases.

Comparison of larval performance and oviposition preference of Spodoptera frugiperda among three host plants: Potential risks to potato and tobacco crops.

Fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), is a major polyphagous pest with the potential to seriously damage various crops. A better understanding of FAW's performance on different hosts may help to predict which plants will be attacked when the preferred host is absent, and facilitate the development of effective pest management practices. We compared the larval performance of FAW fed on maize with that of FAW fed on potato and tobacco, which are important crops in China, using an age-stage two-sex life table and adult female oviposition preference experiments. In cage experiments with potato, tobacco, or maize as the host, FAW reared on maize exhibited the strongest performance with shorter developmental time in the larval stage, longer longevity, and a higher reproductive rate in adults. Females oviposited on maize in preference to potato or tobacco. Compared with larvae fed on maize, those fed on potato and tobacco exhibited significantly lower survival, with only 31.61% and 8.13% developing to the adult stage, respectively. Several life table parameters, including the mean generation time (T), net reproductive rate (R0 ), finite rate of increase (λ), and intrinsic rate of natural increase (r) were negatively affected in FAW fed on potato and tobacco. Our results support the preference-performance hypothesis, that is, that herbivore females maximize fitness by choosing host plants associated with strong larval performance. Although larvae and adults performed poorly on potato and tobacco, their offspring will be capable of establishing populations on them, posing a potential threat to these crops in China.

Comparative pharmacokinetic study on three formulations of Astragali Radix by an LC-MS/MS method for determination of formononetin in human plasma.

Astragali Radix (AR) is a widely used traditional Chinese medicine for healing the cardiovascular, liver and immune systems. Recently, superfine pulverizing technology has been applied to developing novel formulations to improve bioavailability of the active constituents in herbs, such as ultrafine granular powder of AR. In this study, a universal and sensitive quantitative method based on LC-MS/MS was employed for determining formononetin, the main flavonoid in AR, in human plasma for comparative pharmacokinetics of three oral formulations of AR. Formononetin and IS (quercetin) were extracted by ethyl acetate from human plasma and were separated on a C18 column with a mobile phase consisting of acetonitrile and 0.1% formic acid. Positive-ion electrospray-ionization mode was applied in mass spectrometric detection. The quantitative method was validated with regards to selectivity, linearity, accuracy and precision, matrix effect, extraction recovery and stability, and was applied to comparing the pharmacokinetics of ultrafine granular powder (UGP), ultrafine powder (UP) and traditional decoction pieces (TDP) of AR after oral administration. The peak concentration and areas under the concentration-time curve of formononetin in UGP and UP were significantly higher than those of TDP. UGP and UP could significantly improve the bioavailability of AR in human compared with TDP after oral administration.

A new xanthone glycoside from Pyrrosia sheareri.

A new xanthone glycoside, 3,5,7,8-tetramethoxyxanthone-1-O-ß-D-glucopyranoside (1), along with five known compounds, mangiferin (2), kaempferol (3), quercetin (4), chlorogenic acid (5) and diploptene (6), was isolated from the whole plants of Pyrrosia sheareri (Bak.) Ching. The structure of compound 1 was established on the basis of extensive spectroscopic analyses and chemical methods.

Three New Cytotoxic Steroidal Alkaloids from Sarcococca hookeriana.

Three new steroidal alkaloids with an unusual 3α tigloylamide group, named sarchookloides A⁻C (1⁻3), were isolated along with four known compounds (4⁻7) from the roots of Sarcococca hookeriana. Their structures and relative configuration were elucidated on the basis of spectroscopic methods including MS, UV, IR, 1D, and 2D NMR data. The isolated compounds were evaluated for their cytotoxicity against five human cancer cell lines: Hela, A549, MCF-7, SW480, and CEM in vitro. All three amide substituted steroidal alkaloids exhibited significant cytotoxic activities with IC50 values of 1.05⁻31.83 µM.

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

Fifteen known compounds were isolated from Swertia delavayi by silica gel, Sephadex LH-20 and Rp-18 column chromatographies. Based on extensive spectroscopic analysis (MS, 1H, 13C-NMR), their structures were identified aserythrocentaurin (1), erythrocentaurindimethylacetal (2), sweroside (3), swertiamarin (4), gentiopicroside (5), swertiakoside A (6), 2'-O-acetylswertiamarin (7), 4'-O-[(Z) -coumaroyl] swertiamarin (8), 1,5,8-trihydroxy-3-methoxyxanthone (9), 8-O-ß-D-glucopyranosyl-1-hydroxy-2,3, 5-trimethoxyxanthone (10), 8-O-[ß-D-xyl- opyranosyl-(1 --> 6)-ß-D-glucopyranosyl]-7,8-dihydroxy-3-methoxyxanthone (11), isovitexin (12), ß-sitosterol (13), daucosterol (14), and oleanolic acid (15). Among them, ten ones (14, 7-11, 13) were obtained from S. delavayi for the first time. The isolates were evaluated for their anti-HBV activities in HepG 2. 2. 15 cell line in vitro. The results showed that compound 1, 2, 6, 7, 9 and 12 exhibited significant inhibitory activity on HBV DNA replication with IC50 values from 0.05 to 1.46 mmol x L(-1).

Isolation, synthesis and anti-hepatitis B virus evaluation of p-hydroxyacetophenone derivatives from Artemisia capillaris.

p-Hydroxyacetophenone (p-HAP), as a main hepatoprotective and choleretic constituent of Artemisia capillaris, was revealed with anti-hepatitis B virus (HBV) effects in recent investigation. In addition to p-HAP, four derivatives of p-HAP were also isolated from A. capillaris by various chromatographic methods. Subsequent structural modification on p-HAP and its glycoside led to the synthesis of 28 additional derivatives, of which 13 compounds showed activity inhibiting hepatitis B surface antigen (HBsAg) secretion; and 18 compounds possessed inhibition on HBV DNA replication. The primary structure-activity relationships (SARs) suggested that the conjugated derivatives of p-HAP glycoside and substituted cinnamic acids (2a-2i) obviously enhanced the activity against HBV DNA replication with IC50 values ranged from 5.8 to 74.4 µM.

[Chemical constituents of Swertia patens].

Chemical constituents of Swertia patens. The whole plant of air-dried Swertia patens was extracted with 90% EtOH. The water extract was suspended in H2O and extracted with petroleum ether, EtOAc and n-BuOH, successively. The compounds were isola- ted and purified by column chromatography from the EtOAc fraction, and identified based on spectral analyses (MS, ¹H-NMR, ¹³C- NMR). Eighteen compounds were isolated and elucidated as 3, 4-dihydro-1H,6H,8H-naptho [1,2-c:4,5-c', d'dipyrano-1, 8-dione (1), angelone (2), gentiogenal (3), erythricin (4), erythrocentaurin (5), gentianine (6), swertiakoside B (7), swertiamarin (8), 2'-O-actylswertiamarin (9), amarogentin (10), 1, 3, 5-trihydroxyxanthone (11), 1, 3-dihydroxy-5-methoxyxanthone (12), 1-hydroxy- 2, 3, 5-trimethoxyxanthone (13), gentiocrucine (14), 3-hydroxyphenylketone (15), n-hexacosyl ester 4-hydroxy-trans-cinnamate (16), n-hexacosyl ester 4-hydroxy-cis-cinnamate (17), and cholest-4-en-3-one (18). Compounds 1-7, 9-18 were obtained from S. patens for the first time.

[Chemical constituents of Swertia kouitchensis Franch].

This study is to investigate the chemical constituents of Swertia kouitchensis. The whole plants of air-dried Swertia kouitchensis was extracted with 90% EtOH. The water extract was suspended in H2O and extracted with petroleum ether, EtOAc and n-BuOH, successively. The compounds were isolated and purified by column chromatography from the EtOAc fraction, and their structures were identified based on spectral analyses (MS, 1H-NMR, 13C-NMR). Twenty-eight compounds were obtained, and characterized as erythrocentaurin (1), erythrocentaurin dimethylacetal (2), swertiamarin (3), vogeloside (4), 2'-O- actylswertiamarin (5), swertianoside D (6), gentiocrucines A-B (7-8), gentiocrucine (9), 1-hydroxy-3, 7, 8-trimethoxyxanthone (10), 1-hydroxy-3, 5, 6-trimethoxyxanthone (11), 3-epitaraxerol (12), erythrodiol 3-O-palmitate (13), (+) -syringaresinol (14), caffeic acid (15), trans-coniferyl aldehyde (16), trans-coniferyl alcohol (17), 3, 4-dihydroxybenzoic acid (18), 4-hydroxy-3-methoxybenzoic acid (19), 3, 4-dihydroxybenzoic aldehyde (20), 2, 3-dihydroxybenzoic acid (21), 4-hydroxybenzoic acid (22), 3-acetoxybenzoic acid (23), 3-hydroxybenzoic acid (24), 3-hydroxybenzoic alcohol (25), nicotinic acid (26), 2-furoic acid (27), and uracil (28). Compounds 1-4, 6-28 were obtained from S. kouitchensis for the first time.

[Chemical constituents of Swertia angustifolia].

This present work is to study the chemical constituents of Swertia angustifolia. The whole plants of air-dried Swertia angustifolia was extracted with 90% EtOH. The water extract was suspended in H2O and extracted with petroleum ether, EtOAc and nBuOH, successively. The compounds were isolated and purified by column chromatography from the EtOAc fraction, and identified based on spectral analyses (MS, 1H-NMR, 13C-NMR). Fourteen compounds were isolated and characterized as 1, 8-dihydroxy-3, 7-dimethoxyxanthone (1), 1, 8-dihydroxy-3, 5, 7-trimethoxyxanthone (2), 7-hydroxy-3, 8-dimethoxyxanthone-1-O-ß-D-glucopyranoside (3), 8-0-[ß-D-xylopyranosyl-(1-6) -ß-D-glucopyranosyl] -1, 7-dihydroxy-3-methoxyxanthone (4), (+) -syringaresinol (5), ferulic acid (6), trans-coniferyl aldehyde (7), sinapaldehyde (8), trans-coniferyl alcohol (9), 3, 4-dihydroxybenzoic acid (10), 2-hydroxybenzoic acid (11), isophthalic acid (12), 2-furoic acid (13), and 2-methyl-4(3H)-quinazolinone(14). Compounds 2-14 were obtained from this plant for the first time.

UFLC/MS-IT-TOF guided isolation of anti-HBV active chlorogenic acid analogues from Artemisia capillaris as a traditional Chinese herb for the treatment of hepatitis.

ETHNOPHARMACOLOGICAL RELEVANCE: Hepatitis B induced by HBV is a serious health problem. Artemisia capillaris (Yin-Chen) has long been used to treat hepatitis in traditional Chinese medicine. Coumarins, flavonoids and organic acids were revealed as its hepatoprotective and choleretic components, but its anti-HBV active components remain unknown. This current study focused on its anti-HBV active constituents by various chromatographic methods. MATERIAL AND METHODS: LC/MS and bioassay-guided fractionation on the active extract of Artemisia capillaris led to the isolation of nine chlorogenic acid analogues. Structures of the isolates were elucidated by MS/MS and NMR techniques. Anti-HBV assay was performed on HepG 2.2.15 cell line in vitro: reduction of HBsAg and HBeAg secretions was measured by an ELISA method; inhibition of HBV DNA replication was monitored by real-time quantitative PCR and cellular toxicity was assessed by a MTT method. RESULTS: The 90% ethanol extract of Artemisia capillaris (Fr. AC) showed significantly inhibitory activity on HBV DNA replication with an IC50 value of 76.1 ± 3.9 µg/mL and low cytotoxic effects (SI>20.1). To clarify its active constituents, the extract was further separated into 3 sub-fractions (AC-1, AC-2 and AC-3), of which Fr. AC-2 was the most active fraction against HBeAg secretion and HBV DNA replication with IC50 values of 44.2 ± 2.8 and 23.2 ± 1.9 µg/mL. Nine chlorogenic acid analogues were detected from the active part (Fr. AC-2) by a LC/MS technique and further separated by a HPLC method. The isolates were determined as chlorogenic acid (1), cryptochlorogenic acid (2), neochlorogenic acid (3), 3,5-dicaffeoylquinic acid (4), 4,5-dicaffeoylquinic acid (5), 3,4-dicaffeoylquinic acid (6), chlorogenic acid methyl ester (7), cryptochlorogenic acid methyl ester (8), neochlorogenic acid methyl ester (9). Compounds 1-6 possessed potent activity against HBV DNA replication with IC50 values in the range of 5.5 ± 0.9-13.7 ± 1.3 µM. Di-caffeoyl analogues (4-6) also exhibited activity against the secretions of HBsAg and HBeAg. Esterified analogues (7-9) showed dramatically decreased anti-HBV activity, indicating that carboxyl group is closely associated to the anti-HBV activity. CONCLUSIONS: This investigation was focused on the active fractions of Artemisia capillaris and their active compositions, which showed that Fr. AC-2 was the main active section of Artemisia capillaris and chlorogenic acid analogues were the main constituents contributing to its anti-HBV activity. These results support the ethnopharmacological use of Artemisia capillaris as anti-HBV agents.

Polyacetylenes and anti-hepatitis B virus active constituents from Artemisia capillaris.

Three new polyacetylenes, 8-(Z)-decene-4, 6-diyne-1, 3, 10-triol (1), 1, 3S, 8S-trihydroxydec-9-en-4, 6-yne (2), 3S, 8S-dihydroxydec-9-en-4, 6-yne 1-O-ß-D-glucopyranoside (3), and one new glucosyl caffeoate, 1-O-ethyl-6-O-caffeoyl-ß-D-glucopyranose (4), together with 34 known compounds were isolated from Artemisia capillaris. The structures of the new compounds were determined by extensive spectroscopic analyses including 1D and 2D NMR, HRESIMS, [α]D and CD experiments. Among them, 19 compounds showed activity inhibiting HBsAg secretion; 20 compounds showed activity inhibiting HBeAg secretion; and 25 compounds possessed inhibitory activity against HBV DNA replication according to our anti-HBV assay on HepG 2.2.15 cell line in vitro. The most active compound 12 could inhibit not only the secretions of HBsAg and HBeAg, but also HBV DNA replication with IC50 values of 15.02 µM (SI=111.3), 9.00 µM (SI=185.9) and 12.01 µM (SI=139.2).

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

Four new triterpenoids, sweriyunnangenin A (1), sweriyunnanosides A (2), B (3) and C (4), along with nineteen known compounds (5-23) were isolated from Swertia yunnanensis. Based on extensive spectroscopic analyses (1D- and 2D-NMR, HRESIMS, UV, IR, [α]D), the structures of sweriyunnangenin A (1), sweriyunnanosides A (2), B (3) and C (4) were elucidated as taraxer-14-ene-3α,6ß-diol, oleanolic acid 28-O-ß-D-glucopyranosyl-(1→2)-O-ß-D-glucopyranoside, 2α,3ß-di-hydroxyolean-12-en-28-oic acid 28-O-ß-D-glucopyranosyl(1→6)-ß-D-glucopyranosyl (1→6)-ß-D-glucopyranosyl(1→2)-ß-D-glucopyranoside and hederagenin 28-O-ß-D-glucopyranosyl(1→6)-ß-D-glucopyranosyl(1→6)-ß-D-glucopyranosyl(1→2)-ß-D-glucopyranoside, respectively. Twenty-two compounds were evaluated for their anti-HBV activities on the HepG 2.2.15 cell line in vitro, of which nine compounds showed potent anti-HBV activities. Compounds 1, 5-6, 14-16 and 19 showed activities against the secretion of HBsAg (IC50 values from 0.10 to 1.76 mM) and HBeAg (IC50 values from 0.04 to 1.41 mM), and compounds 11 and 13-16 exhibited significant inhibition on HBV DNA replication (IC50 values from 0.01 to 0.09 mM).

Xanthones with anti-hepatitis B virus activity from Swertia mussotii.

Two new xanthones, 8-O-ß-D-glucopyranosyl-1-hydroxy-2,3,5-trimethoxyxanthone (1) and 8-O-[ß-D-xylopyranosyl-(1 → 6)-ß-D-glucopyranosyl]-1-hydroxy-2,3,5-trimethoxyxanthone (2), along with eighteen known xanthones (3-20) were isolated from Swertia mussotii. Their structures were elucidated on the basis of extensive spectroscopic analyses (1D- and 2D-NMR, HRESIMS, UV, IR, [α]D). All compounds were evaluated for their anti-hepatitis B virus activities on HepG 2.2.15 cells line in vitro, and compounds 3-10 exhibited significant activity inhibiting hepatitis B virus DNA replication with IC50 values from 0.01 mM to 0.13 mM. Compounds 3-5 showed remarkable activity with IC50 values of 0.77, > 0.98, and 0.21 mM for HBsAg, and < 0.62, 0.35, and 0.04 mM for HBeAg, respectively. Meanwhile, the effects of different substitutions on the anti-hepatitis B virus activity of xanthones from S. mussotii were discussed.