Anti-HBV Activities of Cembranoids from the South China Sea Soft Coral Sinularia pedunculata and Their Structure Activity Relationship.

Hepatitis B Virus (HBV) infection is a global public health challenge that seriously endangers human health. Soft coral, as a major source of terpenoids, contains many structurally novel and highly bioactive compounds. Sixteen cembranoids (1-16), including a new one named sinupedunol B (16), were isolated from the South China Sea Soft coral Sinularia pedunculata. The structure of the sinupedunol B (16) was determined through a combination of spectroscopic analysis and X-ray single-crystal diffraction. In this study, cembranoids isolated from Sinularia pedunculata were found of anti-HBV activity for the first time. Among them, flexilarin D (6) showed significant anti-HBV activity with an IC50 value of 5.57 µM without cytotoxicity. We then analyzed the structure-activity relationship (SAR). Furthermore, it is demonstrated that flexilarin D (6) can accelerate the formation of capsid, inhibit HBeAg, HBV core particle DNA, HBV total RNA and pregenomic RNA in a dose dependent manner. We also confirmed the anti-HBV activity of 6 in HepG2-NTCP infection system. Finally, we demonstrated the anti-HBV mechanism of these compounds by inhibiting the ENI/Xp enhancer/promoter.

Design and Synthesis of (3-Phenylisoxazol-5-yl)methanimine Derivatives as Hepatitis B Virus Inhibitors.

Series of (3-phenylisoxazol-5-yl)methanimine derivatives were synthesized, and evaluated for anti-hepatitis B virus (HBV) activity in vitro. Half of them more effectively inhibited HBsAg than 3TC, and more favor to inhibit secretion of HBeAg than to HBsAg. Part of the compounds with significant inhibition on HBeAg were also effectively inhibit replication of HBV DNA. Compound (E)-3-(4-fluorophenyl)-5-((2-phenylhydrazineylidene)methyl)isoxazole inhibited excellently HBeAg with IC50 in 0.65 µM (3TC(Lamivudine) in 189.90 µM), inhibited HBV DNA in 20.52 µM (3TC in 26.23 µM). Structures of compounds were determined by NMR and HRMS methods, and chlorination on phenyl ring of phenylisoxazol-5-yl was confirmed by X-ray diffraction analysis, and the structure-activity relationships (SARs) of the derivatives was discussed. This work provided a new class of potent non-nucleoside anti-HBV agents.

Structure-Based Molecular Networking for the Discovery of Anti-HBV Compounds from Saussurea lappa (Decne.) C.B Clarke.

It is a crucial to find target compounds in natural product research. This study presents a concept of structure-guided isolation to find candidate active molecules from herbs. We establish a process of anti-viral sesquiterpene networking. An analysis of the networking suggested that new anti-HBV sesquiterpene may be attributable to eudesmane-, guaiane-, cadinane-, germacane- and bisabolane-type sesquiterpenes. In order to evaluate the efficiency of the structure-based molecular networking, ethanol extract of Saussurea lappa (Decne.) C.B Clarke was investigated, which led to the isolation of two guaiane-type (1 and 14), ten eudesmane-type (2-5 and 8-13), two chain (6 and 7) and one germacrane-type (15) sesquiterpenes, including seven new ones, lappaterpenes A-G (1-7), which are reported on herein. The absolute configurations of the new compounds were established by coupling constants, calculated ECD and ROESY correlations, as well as comparisons of optical rotation values with those of known compounds. The absolute configuration of compound 2 was further confirmed by X-ray diffraction. Compounds 1-15 were evaluated for their potency against hepatitis B virus. Compounds 4, 6, 7 and 9 showed effect on HBsAg with inhibition ratios of more than 40% at 30 µM concentrations. Compounds 14 and 15 inhibited HBsAg secretion with the values of IC50 0.73 ± 0.18 and 1.43 ± 0.54 µM, respectively. Structure-based molecular networking inspired the discovery of target compounds.

Immunomodulatory Efficacy-Mediated Anti-HCV and Anti-HBV Potential of Kefir Grains; Unveiling the In Vitro Antibacterial, Antifungal, and Wound Healing Activities.

The utilization of fermented foods with health-promoting properties is becoming more popular around the world. Consequently, kefir, a fermented milk beverage made from kefir grains, was shown in numerous studies to be a probiotic product providing significant health benefits. Herein, we assessed the antibacterial and antifungal potential of kefir against a variety of pathogenic bacteria and fungi. This study also showed the effectiveness of kefir in healing wounds in human gastric epithelial cells (GES-1) by (80.78%) compared with control (55.75%) within 48 h. The quantitative polymerase chain reaction (qPCR) results of kefir-treated HCV- or HBV- infected cells found that 200 µg/mL of kefir can eliminate 92.36% of HCV and 75.71% of HBV relative to the untreated infected cells, whereas 800 µg/mL (the highest concentration) completely eradicated HCV and HBV. Moreover, the estimated IC50 values of kefir, at which HCV and HBV were eradicated by 50%, were 63.84 ± 5.81 µg/mL and 224.02 ± 14.36 µg/mL, correspondingly. Kefir can significantly suppress the elevation of TNF-α and upregulate IL-10 and INF-γ in both treated HCV- and HBV-infected cells. High-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS) analysis of kefir revealed the presence of numerous active metabolites which mainly contribute to the antimicrobial, antiviral, and immunomodulatory activities. This study demonstrated, for the first time, the anti-HBV efficacy of kefir while also illustrating the immunomodulatory impact in the treated HBV-infected cells. Accordingly, kefir represents a potent antiviral agent against both viral hepatitis C and B, as well as having antimicrobial and wound healing potential.

Design, synthesis and anti-HBV activity of NVR3-778 derivatives.

NVR3-778, one of the most advanced capsid assembly modulators (CAMs), is currently in phase II clinical trial for the treatment of HBV infection. In this study, we reported the first structure optimization of NVR3-778. Compound 2d was found to exhibit more potent anti-HBV activity (IC50: 0.25 µM), lower cytotoxicity (CC50: 10.68 µM) and higher selectivity index (SI: 40.72) than NVR3-778 (IC50: 0.33 µM; CC50: 5.14 µM; SI: 18.36) in vitro, and also display similar inhibitory effect on the assembly of HBV capsids as NVR3-778. Molecular docking further suggested that compound 2d might form a stronger interaction with core protein. Moreover, compound 2d also showed acceptable pharmacokinetic profiles. Currently compound 2d was selected as a new lead for further modifications, and studies to determine the in vivo anti-HBV studies of 2d will begin soon.

Design, synthesis, and biological evaluation of novel 2'-deoxy-2'-fluoro-2'-C-methyl 8-azanebularine derivatives as potent anti-HBV agents.

Hepatitis B virus (HBV) is a global health problem requiring more efficient and better tolerated anti-HBV agent. In this paper, a series of novel 2'-deoxy-2'-fluoro-2'-C-methyl-ß-d-arabinofuranosyl 8-azanebularine analogues (1 and 2a) and N4-substituted 8-azaadenosine derivatives (2b-g) were designed, synthesized and screened for in vitro anti-HBV activity. Two concise and practical synthetic routes were developed toward the structural motif construction of 2'-deoxy-2'-fluoro-2'-C-methyl-ß-d-arabinofuranosyl 8-azainosine from the ribonolactone 3 under mild conditions. The in vitro anti-HBV screening results showed that these 8-azanebularine analogues had a significant inhibitory effect on the expression of HBV antigens and HBV DNA at a concentration of 20 µM. Among them, halogen-substituted 8-azaadenosine derivative 2g displayed activities comparable to that of 3TC. In particular, 2g retained excellent activity against lamivudine-resistant HBV mutants.

Chemical constituents from Lonicera japonica flower buds and their anti-hepatoma and anti-HBV activities.

Three new naturally occurring monoterpenoids, japopenoid A (1), japopenoid B (23) japopenoid C (24), and one new caffeoylquinic acid derivative (28), together with thirty-one known compounds (2-22, 25-27, 29-35), were isolated and identified from the flower buds of Lonicera japonica Thunb. Their structures were determined by extensive 1D and 2D NMR spectroscopic methods, high-resolution mass spectrometry, and the absolute configurations of 1, 23, 24 were determined by comparison of their electronic circular dichroism (ECD) spectrum with literature and theoretical calculation. Structurally, compound 1 is a monoterpenoid featured with an unusual tricyclic skeleton. All compounds (1-35) were evaluated for their cytotoxicities against human liver cancer cell lines (HepG 2 and SMMC-7721). Compound 12 exhibited the most potent activity with IC50 values of 26.54 ±â€¯1.95 and 8.72 ±â€¯1.57 µg/ml against HepG 2 and SMMC-7721, and the IC50 values of compound 13 were 26.54 ±â€¯1.95 and 12.35 ±â€¯1.43 µg/ml, respectively. Western blot results further proved that compound 13 induces hepatoma cell apoptosis via the intrinsic apoptosis pathway. In addition, most terpenoids showed inhibitory activity against HBsAg and HBeAg secretion, and HBV DNA replication. In particular, 25 µg/mlof compound 11 inhibits HBsAg and HBeAg secretion, and HBV DNA replication by 39.39 ±â€¯5.25, 15.64 ±â€¯1.25, and 16.13 ±â€¯4.10% compared to the control (p < 0.05). These results indicated that L. japonica flower buds could be served as functional food for anti-hepatoma and anti-HBV activities.

Design, Synthesis, and Bioactive Screen In Vitro of Cyclohexyl (E)-4-(Hydroxyimino)-4-Phenylbutanoates and Their Ethers for Anti-Hepatitis B Virus Agents.

A series of oxime Cyclohexyl (E)-4-(hydroxyimino)-4-phenylbutanoates and their ethers were designed, synthesized, and evaluated for anti-hepatitis B virus (HBV) activities with HepG 2.2.15 cell line in vitro. Most of these compounds possessed anti-HBV activities, and among them, compound 4B-2 showed significant inhibiting effects on the secretion of HBsAg (IC50 = 63.85 ± 6.26 µM, SI = 13.41) and HBeAg (IC50 = 49.39 ± 4.17 µM, SI = 17.34) comparing to lamivudine (3TC) in HBsAg (IC50 = 234.2 ± 17.17 µM, SI = 2.2) and HBeAg (IC50 = 249.9 ± 21.51 µM, SI = 2.07). Docking study of these compounds binding to a protein residue (PDB ID: 3OX8) from HLA-A2 that with the immunodominant HBcAg18-27 epitope (HLA-A2.1- restricted CTL epitope) active site was carried out by using molecular operation environment (MOE) software. Docking results showed that behaviors of these compounds binding to the active site in HLA-A protein residue partly coincided with their behaviors in vitro anti-HBV active screening.

Discovery of Oxime Ethers as Hepatitis B Virus (HBV) Inhibitors by Docking, Screening and In Vitro Investigation.

A series of oxime ethers with C6-C4 fragment was designed and virtually bioactively screened by docking with a target, then provided by a Friedel-Crafts reaction, esterification (or amidation), and oximation from p-substituted phenyl derivatives (Methylbenzene, Methoxybenzene, Chlorobenzene). Anti-hepatitis B virus (HBV) activities of all synthesized compounds were evaluated with HepG2.2.15 cells in vitro. Results showed that most of compounds exhibited low cytotoxicity on HepG2.2.15 cells and significant inhibition on the secretion of HBsAg and HBeAg. Among them, compound 5c-1 showed the most potent activity on inhibiting HBsAg secretion (IC50 = 39.93 µM, SI = 28.51). Results of the bioactive screening showed that stronger the compounds bound to target human leukocyte antigen A protein in docking, the more active they were in anti-HBV activities in vitro.

Hyperoside nanocrystals for HBV treatment: process optimization, in vitro and in vivo evaluation.

The aim of this study was to develop hyperoside (Hyp) nanocrystals to enhance its dissolution rate, oral bioavailability and anti-HBV activity. Hyp nanocrystals were prepared using high pressure homogenization technique followed by lyophilization. A Box-Behnken design approach was employed for process optimization. The physicochemical properties, pharmacokinetics and anti-HBV activity in vivo of Hyp nanocrystal prepared with the optimized formulation were systematically investigated. Hyp nanocrystals prepared with the optimized formulation was found to be rod shaped with particle size of 384 ± 21 nm and PDI of 0.172 ± 0.027. XRPD studies suggested slight crystalline change in drug. Dissolution rate obtained from Hyp nanocrystals were markedly higher than pure Hyp. The nanocrystals exhibited enhanced Cmax (7.42 ± 0.73 versus 3.80 ± 0.66 mg/L) and AUC0 - t (193.61 ± 16.30 versus 91.92 ± 17.95 mg·h/L) with a 210.63% increase in relative bioavailability. Hyp nanocrystals exhibited significantly greater anti-HBV activity than Hyp. These results suggested that the developed nanocrystals formulation had a great potential as a viable approach to enhance the bioavailability of Hyp.

Two new secoiridoids and other anti-hepatitis B virus active constituents from Swertia patens.

Two new secoiridoids, swerpatic acid (1) with an unusual C8 skeleton and swerpalactone (2), were isolated along with ten known compounds (3-12) from the whole plants of Swertia patens. Their structures were elucidated by comprehensive spectroscopic analyses. Eight compounds were evaluated for their anti-hepatitis B virus (HBV) activities on Hep G 2.2.15 cell line in vitro. Compounds 4 and 10 showed moderate inhibitory activities on the secretion of HBsAg with IC50 values of 1.96 and 0.50 mM.

New Anti-HBV C-Boivinopyranosyl Flavones from Alternanthera philoxeroides.

C-boivinopyranosyl flavones have rarely been isolated from nature. In the search for anti-HBV (hepatitis b virus) constituents of Alternanthera philoxeroides, two new compounds, luteolin-6-C-ß-D-boivinopyranosyl-3'-O-ß-D-glucopyranoside (1) and chrysoeriol-6-C-ß-D-boivinopyranosyl-4'-O-ß-D-glucopyranoside (2), along with three known C-boivinopyranosyl flavones (compounds 3-5) were isolated. Their structures were determined by spectroscopic analyses including 1D and 2D NMR, HR-ESI-MS, IR spectra. Compounds 1, 2 and 3 showed significant anti-HBV activities through specifically inhibiting the secretion of HBsAg in HepG2.2.15.

Synthesis of erythrocentaurin derivatives as a new class of hepatitis B virus inhibitors.

Twenty-four derivatives of erythrocentaurin (ET) were synthesized and evaluated for their anti-HBV activities on HepG 2.2.15 cell line in vitro. Eight compounds 1, 2, 5, 8, 9, 1e, 1k, and 1m increased activity against HBV DNA replication with the SI values higher than 11. In particular, derivatives 1e and 1k exhibited the most potent inhibition on HBV DNA replication with the IC50 values of 0.026 mM (SI>70.8) and 0.045 mM (SI>36.0), respectively. The primary structure-activity relationships (SARs) of ET derivatives were summarized for exploring potent anti-HBV agents.

A coumarin lignanoid from the stems of Kadsura heteroclita.

Coumarinlignan (1), possessing a unique coumarin-containing lignan skeleton, was isolated from the stems of Kadsura heteroclita. Its structure and absolute configuration were determined by spectroscopic techniques, especially 2D NMR and X-ray crystallographic data analyses. The proposed biosynthetic pathway is discussed. This new compound showed good anti-HBV activity against HBeAg and HBsAg, and moderate anti-fibrotic and neuroprotective activities.

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.

Synthesis, structure-activity relationships and biological evaluation of dehydroandrographolide and andrographolide derivatives as novel anti-hepatitis B virus agents.

Dehydroandrographolide and andrographolide, two natural diterpenoids isolated from Andrographis paniculata possessed activity against HBV DNA replication with IC50 values of 22.58 and 54.07µM and low SI values of 8.7 and 3.7 in our random assay. Consequently, 48 derivatives of dehydroandrographolide and andrographolide were synthesized and evaluated for their anti-HBV properties to yield a series of active derivatives with lower cytotoxicity, including 14 derivatives against HBsAg secretion, 19 derivatives against HBeAg secretion and 38 derivatives against HBV DNA replication. Interestingly, compound 4e could inhibit not only HBsAg and HBeAg secretions but also HBV DNA replication with SI values of 20.3, 125.0 and 104.9. Furthermore, the most active compound 2c with SI value higher than 165.1 inhibiting HBV DNA replication was revealed with the optimal logP value of 1.78 and logD values. Structure-activity relationships (SARs) of the derivatives were disclosed for guiding the future research toward the discovery of new anti-HBV drugs.

Solamargine acts as an antiviral by interacting to MZF1 and targeting the core promoter of the hepatitis B virus gene.

BACKGROUND: Hepatitis B virus (HBV) infection is still a serious threat to global health and can lead to a variety of liver diseases, including acute and chronic hepatitis, liver cirrhosis, liver failure, hepatocellular carcinoma (HCC), and so on. At present, there are mainly two kinds of drugs for the treatment of hepatitis B at home and abroad: interferon (IFN) and nucleoside/nucleotide analogs (NAs). In recent years, natural compounds have been considered an important source for the development of new anti-HBV drugs due to their complex structure, diverse components, high efficiency, and low toxicity. Many studies have demonstrated that Solamargine has significant anticancer activity, but the antiviral effect is rarely studied. This study aimed to verify the anti-HBV effect of Solamargine and to explore the specific mechanism. METHOD: The relative expression of HBV pregenomic RNA (pgRNA) was detected by reverse transcription real-time fluorescence quantitative PCR (RT-qPCR). Northern blot and western blot were used to detect the relative expression of HBV pgRNA and target protein. PCR was used in the construction of HBV pg-promoter, ENII/BCP, and a series of gene deletion mutant fluorescent reporter vectors. The fluorescence relative expression of each mutant was detected by Renilla luciferase assay. RESULTS: By binding to MZF1 (Myeloid zinc finger protein 1, MZF1), Solamargine inhibits HBV core promoter activity, reduces pregenomic RNA level, and inhibits HBV, achieving antiviral effects.

Lappanolides A-N, fourteen undescribed sesquiterpenoids from Saussurea costus (Syn. Saussurea lappa) and their anti HBV activity.

Lappanolides A-N (1-14), 14 undescribed sesquiterpenoids, along with 23 known ones (15-37), were isolated from the roots of Saussurea costus, which were primarily categorized into eudesmane, guaiane, and germacrane types. Lappanolide A (1) possessed an unprecedented pseudo-disesquiterpenoids. Their structures and absolute configurations were established using physical data analyses (HRESIMS, IR, 1D and 2D NMR) and ECD calculations. All isolated compounds were tested for anti-hepatitis B virus (anti-HBV) activity. Ten compounds (1, 9, 11, 12, 19, 22, 28, 29, 31, and 36) exhibited activities against HBsAg secretions as determined by ELISA assay, with IC50 values ranging from 5.2 to 45.7 µM. In particular, compounds 28 and 29 showed inhibition of HBsAg secretion with IC50 values of 5.28 and 5.30 µM, and CC50 values of 9.85 and 6.37 µM, respectively, though they all exhibited low selectivity. Several compounds displayed cytotoxicity in the MTT assay. Among them, compound 28 was the most notable and was chosen for further study using flow cytometry. The result showed that it significantly induced HepG2 cell arrest in the S phase and induced apoptosis.

Undescribed amino acid-sesquiterpene lactone adducts and sesquiterpene glycosides from the roots of Saussurea lappa and their anti-HBV activity.

Saussurea lappa (Asteraceae family), a traditional Chinese medicine, has been found to possess anti-inflammatory, immune-promoting, antibacterial, antitumor, anti-HBV, cholestatic, and hepatoprotective activities. Herein, two undescribed amino acid-sesquiterpene lactone adducts, saussureamines G and H (1 and 2), and two new sesquiterpene glycosides, saussunosids F and G (3 and 4), along with 26 known sesquiterpenoids (5-30) have been isolated from the roots of S. lappa. Their structures and absolute configurations of these compounds were established by physical data analyses such as HRESIMS, IR, 1D and 2D NMR and ECD calculations. All isolated compounds were tested for anti-hepatitis B virus (anti-HBV) activity. Ten compounds (5, 6, 12, 13, 17, 19, 23, 26, 29, and 30) exhibited activities against the secretions of HBsAg and HBeAg. In particular, compound 6 showed inhibition of HBsAg and HBeAg secretion with IC50 values of 11.24 and 15.12 µM, with SI values of 1.25 and 0.93, respectively. Molecular docking studies were also conducted on the anti-HBV compounds. Overall, this study provides insights into the potential therapeutic uses of the compounds found in the roots of S. lappa, particularly in the treatment of hepatitis B virus infections.

Phenylpropanoids from Brachybotrys paridiformis Maxim. ex Oliv. and their anti-HBV activities.

Using chemical and spectroscopic data, this study on Brachybotrys paridiformis Maxim. ex Oliv. identified four undescribed phenylpropanoids, brachin A-C and brachoside A, together with nine other known compounds. The isolated compounds were tested for anti-hepatitis B virus activities in the HepG2.2.15 cell line. Among them, caffeic anhydride showed the most potent activity.