lignans and nirtetralin

Phyllanthus species exhibit a wide range of in vitro and in vivo pharmacological activities; however, little is known about the compounds present in the extracts that are responsible for such actions.. Development and validation of a simple reversed phase HPLC-PDA method for profiling of phyllanthin, hypophyllanthin, nirtetralin, and niranthin in extracts of Phyllanthus species was carried out.. Separation was achieved using an XBridge column® (150 × 4.6 mm, 5.0 µm id) in an isocratic elution mode with mobile phase comprising of a mixture of acetonitrile and water with TFA (0.05%, v/v, pH = 2.15) at ambient temperature with a flow rate of 1 mL/min.. Phyllanthin, hypophyllanthin, nirtetralin, and niranthin were eluted at mean retention times of 10.47, 11.10, 13.67, and 14.53 min, respectively. LOD and LOQ for all four analytes were 0.75 and 3.00 μg/mL, respectively. RSDr values for intraday and interday precision for phyllanthin, hypophyllanthin, nirtetralin, and niranthin were 0.38-1.32 and 0.45-1.77%; 0.22-3.69 and 0.24-3.04%, 0.73-2.37 and 0.09-0.31%, and 1.56-2.77 and 0.12-0.68%, respectively.. The developed and validated HPLC-PDA method was applied for identification and quantification of phyllanthin, hypophyllanthin, nirtetralin, and niranthin in extracts of different plant parts of selected Phyllanthus species. The outcome of the present investigation could be useful for selection of best species to promote its commercial cultivation and suitable extraction solvent for preparation of lignan-enriched fractions. This HPLC-PDA method could be useful for quality control of herbal formulations containing plants from Phyllanthus species.

Topics: Anisoles; Chromatography, High Pressure Liquid; Dioxoles; India; Lignans; Phyllanthus; Plant Extracts

The present study investigated the abundance, richness, diversity, and community composition of denitrifiers (based on nirS and nosZ genes) in the stratified water columns and sediments in eutrophic Dianchi Lake and mesotrophic Erhai Lake using quantitative PCR assay and high-throughput sequencing analysis. Both nirS- and nosZ denitrifiers were detected in waters of these two lakes. Surface water showed higher nosZ gene density than bottom water, and Dianchi Lake waters had larger nirS gene abundance than Erhai Lake waters. The abundance of sediment nirS- and nosZ denitrifiers in Dianchi Lake was larger than that in Erhai Lake. nirS richness and diversity and nosZ richness tended to increase with increasing sediment layer depth in both lakes. The distinct structure difference of sediment nirS- and nosZ denitrifier communities was found between in Dianchi Lake and Erhai Lake. These two lakes also differed greatly in water denitrifier community structure. Moreover, phylogenetic analysis indicated the presence of several different groups of nirS- or nosZ denitrifiers in both lakes. The novel nirS denitrifiers were abundant in both Dianchi Lake and Erhai Lake, while most of the obtained nosZ sequences could be affiliated with known genera.

Topics: Anisoles; Bacteria; Bacterial Proteins; Biodiversity; Denitrification; Dioxoles; Fresh Water; Geologic Sediments; High-Throughput Nucleotide Sequencing; Lakes; Lignans; Microbial Consortia; Nitrite Reductases; Phylogeny; Polymerase Chain Reaction

Nirtetralin B, a new lignan first reported by our team, is isolated from Phyllanthus niruri L. This plant has long been used in folk medicine for liver protection and antihepatitis B in many Asian countries. This study was designed to evaluate the anti-hepatitis B virus activity of nirtetralin B using HepG2.2.15 cells and duck hepatitis B virus (DHBV) infected ducks as in vitro and in vivo models.. Nirtetralin B was isolated from Phyllanthus niruri L. (Euphorbiaceae) by extraction and chromatographic procedures and the anti-hepatitis B virus activity was evaluated both in vitro and in vivo. The human HBV-transfected liver cell line HepG2.2.15 was used in vitro assay. And the in vivo anti-hepatitis B virus activity was evaluated on the expression of HBV replication, HBsAg, HBeAg, ALT and AST on day 0, 7, 14, 17 after nirtetralin B was dosed intragastricly (i.g.) once a day for 14 days at the dosages of 25, 50 and 100mg/kg/day in the duck hepatitis B virus (DHBV) infected ducks.. In the human HBV-transfected liver cell line HepG2.2.15, nirtetralin B effectively suppressed the secretion of the HBV antigens in a dose-dependent manner with IC50 values for HBsAg of 17.4μM, IC50 values for HBeAg of 63.9μM. In DHBV-infected ducklings, nirtetralin B significantly reduced the serum DHBV DNA, HBsAg, HBeAg, ALT and AST. And analysis of the liver pathological changes confirmed the hepatoprotective effect of nirtetralin B.. The experimental data demonstrated that nirtetralin B exhibits anti-hepatitis B virus activity both in vitro and in vivo.

Topics: Animals; Anisoles; Antiviral Agents; Dioxoles; Dose-Response Relationship, Drug; Ducks; Female; Hep G2 Cells; Hepatitis B; Hepatitis B e Antigens; Hepatitis B Surface Antigens; Hepatitis B virus; Hepatitis B Virus, Duck; Humans; Inhibitory Concentration 50; Lignans; Male; Medicine, Traditional; Phyllanthus; Virus Replication

One new lignan, nirtetralin B, along with its two known stereoisomers were isolated from Phyllanthus niruri L. The structure of the new compound was determined by spectroscopy experiments and x-ray diffraction analysis. These lignans were assayed for anti-hepatitis B virus activities in vitro. Nirtetralin and nirtetralin A, B effectively suppressed the secretion of the HBV antigens in a dose-dependent manner with IC₅₀ values for HBsAg of 9.5 µM (nirtetralin A), 16.7 µM (nirtetralin B) and 97.2 µM (nirtetralin), IC₅₀ values for HBeAg of 17.4 µM (nirtetralin A), 69.3 µM (nirtetralin B) and 232.0 µM (nirtetralin), respectively.

Topics: Anisoles; Antiviral Agents; Dioxoles; Hep G2 Cells; Hepatitis B virus; Humans; Lignans; Molecular Structure; Phyllanthus; Plant Extracts

From the aerial parts of Scoparia dulcis L. (Scrophulariaceae) grown in Vietnam, four scopadulane-type diterpenoids (4-7), of which 7 is new and was given the trivial name scopadulcic acid C, together with nine known compounds were isolated. Their structures were elucidated by spectroscopic analyses. The absolute configurations of 4-7 were ascertained by applying the modified Mosher's method to iso-dulcinol (6). The isolation of the lignans nirtetralin and niranthin for the first time from S. dulcis is also of chemotaxonomic interest. The cytotoxic activity in KB cells, inhibitory effect on LPS/IFNgamma-induced NO production, inhibition of multidrug resistance (MDR), and antibacterial and antifungal activities of the scopadulane-type diterpenoids 4-7 were examined in this study.

Topics: Anisoles; Antifungal Agents; Antineoplastic Agents, Phytogenic; Dioxoles; Diterpenes; Drug Resistance, Multiple; Humans; Inhibitory Concentration 50; Interferon-gamma; Lignans; Lipopolysaccharides; Nitric Oxide; Scoparia; Scrophulariaceae; Staphylococcus aureus; Tumor Cells, Cultured; Vietnam

Previous studies have shown that the extracts obtained from Phyllanthus amarus, and some of the lignans isolated from it, exhibit pronounced antiinflammatory properties. In the present study, we have assessed whether the antiinflammatory actions of these lignans can be mediated by interaction with platelet activating factor (PAF) receptor or interference with the action of this lipid. The local administration of nirtetralin, phyltetralin or niranthin (30 nmol/paw), similar to WEB2170 (a PAF receptor antagonist, 30 nmol/paw), significantly inhibited PAF-induced paw oedema formation in mice. The extracts of P. amarus (100 microg/ml) and niranthin (30 microM), but not nirtetralin or phyltetralin (30 microM), decreased the specific binding of [(3)H]-PAF in mouse cerebral cortex membranes. Furthermore, both niranthin and WEB2170 displaced, in a concentration-dependent manner, the [(3)H]-PAF binding sites. The mean IC(50) values from these effects were 6.5 microM and 0.3 microM, respectively. Additionally, both niranthin and WEB2170 (30 nmol/paw) inhibited the increase of myeloperoxidase activity induced by PAF injection in the mouse paw. When assessed the mouse model of pleurisy induced by PAF, pretreatment with niranthin (100 micromol/kg, p.o.) or WEB2170 (1.7 micromol/kg, i.p.) significantly inhibited PAF-induced protein extravasations. Moreover, in the rat model of PAF-induced allodynia, both niranthin (30 nmol/paw) and WEB2170 (30 nmol/paw) treatment significantly inhibited PAF-induced allodynia. In addition, niranthin had a rapid onset and long-lasting antiallodynic action when compared with WEB2170. Collectively, the present findings suggest that niranthin exhibits antiinflammatory and antiallodynic actions which are probably mediated through its direct antagonistic action on the PAF receptor binding sites.

Topics: Analgesics; Animals; Anisoles; Anti-Inflammatory Agents; Azepines; Binding, Competitive; Carrageenan; Cerebral Cortex; Dioxoles; Inflammation; Lignans; Male; Mice; Pain Measurement; Pain Threshold; Peroxidase; Phyllanthus; Plant Extracts; Platelet Activating Factor; Platelet Aggregation Inhibitors; Platelet Membrane Glycoproteins; Pleurisy; Rats; Rats, Wistar; Receptors, G-Protein-Coupled; Tetrahydronaphthalenes; Time Factors; Triazoles

Using an HBV-producing cell line and inhibition of the expression of the HBsAg and HBeAg as antiviral indicators, a study was conducted on 25 compounds isolated from four Phyllanthus (Euphorbiaceae) plants, including P. amarus Schum. & Thonn., P. multi florus Willd., P. tenellus Roxb. and P. virgatus Forst. f. It was found that niranthin (1), nirtetralin (3), hinokinin (5) and geraniin (13) at the non-cytotoxic concentration of 50 micro m, suppressed effectively both HBsAg and HBeAg expression, with the highest inhibition at 74.3%, 45.3%; 69.6%, 33.9%; 68.1%, 52.3%; 32.1%, 46.6%, respectively. Of these, niranthin (1) showed the best anti-HBsAg activity, while the most potent anti-HBeAg activity was observed with hinokinin (5).

Topics: 4-Butyrolactone; Anisoles; Benzodioxoles; Culture Techniques; Dioxoles; Enzyme-Linked Immunosorbent Assay; Glucosides; Hepatitis B e Antigens; Hepatitis B Surface Antigens; Hepatitis B virus; Humans; Hydrolyzable Tannins; Lignans; Molecular Structure; Phyllanthus; Phytotherapy; Plant Extracts; Tannins