Polyketide Derivatives from the Endophytic Fungus Phaeosphaeria sp. LF5 Isolated from Huperzia serrata and Their Acetylcholinesterase Inhibitory Activities.

The secondary metabolites of Phaeosphaeria sp. LF5, an endophytic fungus with acetylcholinesterase (AChE) inhibitory activity isolated from Huperzia serrata, were investigated. Their structures and absolute configurations were elucidated by means of extensive spectroscopic data, including one- and two-dimensional nuclear magnetic resonance (NMR), high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) analyses, and calculations of electronic circular dichroism (ECD). A chemical study on the solid-cultured fungus LF5 resulted in 11 polyketide derivatives, which included three previously undescribed derivatives: aspilactonol I (4), 2-(1-hydroxyethyl)-6-methylisonicotinic acid (7), and 6,8-dihydroxy-3-(1'R, 2'R-dihydroxypropyl)-isocoumarin (9), and two new natural-source-derived aspilactonols (G, H) (2, 3). Moreover, the absolute configuration of de-O-methyldiaporthin (11) was identified for the first time. Compounds 4 and 11 exhibited inhibitory activity against AChE with half maximal inhibitory concentration (IC50) values of 6.26 and 21.18 µM, respectively. Aspilactonol I (4) is the first reported furanone AChE inhibitor (AChEI). The results indicated that Phaeosphaeria is a good source of polyketide derivatives. This study identified intriguing lead compounds for further research and development of new AChEIs.

New Helvolic Acid Derivatives with Antibacterial Activities from Sarocladium oryzae DX-THL3, an Endophytic Fungus from Dongxiang Wild Rice (Oryza rufipogon Griff.).

Three new helvolic acid derivatives (named sarocladilactone A (1), sarocladilactone B (2) and sarocladic acid A (3a)), together with five known compounds (6,16-diacetoxy-25-hy- droxy-3,7-dioxy-29-nordammara-1,17(20)-dien-21-oic acid (3b), helvolic acid (4), helvolinic acid (5), 6-desacetoxy-helvolic acid (6) and 1,2-dihydrohelvolic acid (7)), were isolated from the endophytic fungus DX-THL3, obtained from the leaf of Dongxiang wild rice (Oryza rufipogon Griff.). The structures of the new compounds were elucidated via HR-MS, extensive 1D and 2D NMR analysis and comparison with reported data. Compounds 1, 2, 4, 5, 6 and 7 exhibited potent antibacterial activities. In particular, sarocladilactone B (2), helvolinic acid (5) and 6-desacetoxy-helvolic acid (6) exhibited strongly Staphylococcus aureus inhibitory activity with minimum inhibitory concentration (MIC) values of 4, 1 and 4 µg/mL, respectively. The structure-activity relationship (SAR) of these compounds was primarily summarized.

Carbazole alkaloids isolated from the branch and leaf extracts of Clausena lansium.

The present study carried out a phytochemical investigation of the methanol extract of the branches and leaves of Clausena lansium and afforded nine carbazole alkaloids (compounds 1-9) including two new carbazole alkaloids, claulansiums A and B (compounds 1 and 2). The new compounds were elucidated on the basis of extensive spectroscopic data (MS, NMR, IR, and UV) and the known compounds were identified by comparing spectroscopic data with those reported in literature. All the isolated compounds were tested for their cytotoxic activity against A549 and Hela cancer cell lines. Our results showed that compounds 2-6 exhibited varying degrees of cytotoxicity to cancer cells, with IC50 values ranging from 8.67 to 98.89 µmol·L-1.

[Flavone C-glycosides from seeds of Ziziphus jujuba var. spinosa].

Five flavone C-glycosides were isolated from the methanol extract of the degrease seeds of Ziziphus jujuba var. spinosa though various column chromatography methods including silica gel, MPLC, and HPLC. The structures were elucidated as 6"-feruloyl- 6'''-vanillylspinosin(1), 6",6'"-diferuloylspinosin(2), spinosin(3), swertisin(4) and isoswertisin(5) based on the NMR and MS spectral data. 1 is a new compound.

Coumarins from roots of Clausena excavata.

Two new coumarins, clauexcavatins A (1) and B (2), along with seven known ones (3-9), were isolated from the roots of Clausena excavata Burm. f. (Rutaceae). Their structures were elucidated on the basis of spectral data.

Anti-angiogenesis and immunomodulatory activities of an anti-tumor sesquiterpene bigelovin isolated from Inula helianthus-aquatica.

Bigelovin is a sesquiterpene lactone isolated from the plant Inula helianthus-aquatica which was traditionally used in cancer treatment in Yunnan, China. The potent apoptotic activities of bigelovin in human leukemia U937 cells were shown in our previous study. The present study investigated the anti-angiogenic and immunomodulatory effects of bigelovin using transgenic zebrafish Tg(fli1a:EGFP)y1 with fluorescent blood vessels and human peripheral blood mononuclear cells (PBMCs), respectively. Furthermore, the inhibitory activities of bigelovin on the human endothelial cell adhesion molecules (CAMs) were also examined. Our results showed that the growth of subintestinal vessels of the bigelovin-treated zebrafish embryos was significantly inhibited and the gene expressions in angiogenesis signaling pathways (e.g. Ang2 and Tie2) of the zebrafish were down-regulated after bigelovin treatment. Besides, the proliferation and Th1 cytokines productions (e.g. IFN-γ, IL-2 and IL-12) were suppressed in bigelovin-treated PBMCs. On the other hand, bigelovin was shown to significantly inhibit the human monocyte adhesion to human endothelial cells and the gene expressions of inflammation-related CAMs (e.g. ICAM-1, VCAM-1 and E-selectin) were significantly down-regulated in bigelovin-treated human endothelial cells. In summary, our data provide the first evidence that bigelovin possesses anti-angiogenic and immunomodulatory activities, suggesting bigelovin may exert multi-target functions against cancer in animal models.

[Chemical constituents contained in ethanol extracts from Acorus tatarinowii and their anti-fatigue activity].

Chemical constituents in ethyl acetate and butanol fractions of ethanol extracts from Acorus tatarinowii were separated by column chromatography. Bufo skeletal muscle fatigue model was established to study the anti-fatigue activity of separated compounds. Five compounds were separated and identified by spectroscopic analysis as acoramone(1),cycloartenone(2),2,4,5-trimethoxyl-2'-butoxy-1,2-phenyl propandiol(3),5-hydroxymethyl furfural(4), and 5-butoxymethyl furfural(5). Compound 3 was a new compound, and compounds 2 and 5 were separated from this plant for the first time. Compound 4 exhibited a notable anti-fatigue activity.

Terpene and lignan glycosides from the twigs and leaves of an endangered conifer, Cathaya argyrophylla.

Labdane diterpene glycosides cathargyroside A and cathargyroside B, monoterpene glycosides vervenone-10-O-ß-D-glucopyranoside and vervenone-10-O-ß-D-apiofuranosyl-(1″→6')-ß-D-glucopyranoside, as well as lignan glycosides cedrusinin-4-O-α-L-rhamnopyranoside and (+)-cyclo-olivil-9'-O-ß-D-xylopyranoside, along with 39 known compounds, were obtained from the methanol extract of the twigs and leaves of Cathaya argyrophylla. These compounds were identified mainly by analyzing their NMR and MS data. Almost all of these compounds were hitherto unknown in this genus. The isolated compounds were screened against Candida albicans and Staphylococcus aureus for antimicrobial assay, and against K562, HT-29, BEL-7402, SGC-7901, B16, BGC-823, U251 and A549 cancer cell lines for cytotoxic activities. One compound showed antimicrobial activity against C. albicans, and four of them displayed cytotoxicity. Similarity analysis on the chemical constituents of the genera Cathaya, Picea and Pinus supported their close phylogenetic relationships.

Zizimauritic acids A-C, three novel nortriterpenes from Ziziphus mauritiana.

Zizimauritic acids A-C (1-3), three novel nortriterpenes with a unique A-nor-E-seco spiro-lactone ceanothane-type triterpene skeleton, together with 3 known triterpenes ceanothenic acid (4), betulinic acid (5), and ceanothic acid (6), were isolated from the roots of Ziziphus mauritiana. Compounds 1-4 showed cytotoxicities with the IC(50) values ranging from 5.05 to 11.94 µg/ml, and compounds 1 and 3 showed an inhibitory effect on the growth of Staphylococcus aureus with the IC(50) values 2.17 and 12.79 µg/ml. A plausible biosynthetic pathway of compounds 1-3 was proposed.

Inhibitory activity of eudesmane sesquiterpenes from Alpinia oxyphylla on production of nitric oxide.

Sixteen eudesmane-type sesquiterpenes including seven new compounds oxyphyllanene A-G (1-2 and 5-9) were isolated from the fruits of Alpinia oxyphylla. Among them, compounds 1-2 are novel trinoreudesmane sesquiterpenes, and 5 is a noreudesmane one. Their structures were established by spectroscopic analysis, including 2D-NMR techniques. Inhibitory activity of compounds 3-8 and 10-16 were tested against nitric oxide production in LPS and IFN-γ-induced RAW 264.7 murine macrophages, and their IC(50) values ranged from 9.85 to 13.95 µg/ml.

Cyclopeptide Alkaloids from Ziziphus apetala.

Six novel Ia3-type cyclopeptide alkaloids (1-6) were isolated from stems of Ziziphus apetala. Compound 5 and the known compounds mauritine A (7) and mauritine F (8) were isolated from the roots. Their structures were determined by spectroscopic analyses and chemical methods. The total alkaloids from the roots and the isolated cyclopeptide alkaloids were tested for antidepressant behavior on mice, cytotoxicity, and 11ß-hydroxysteroid dehydrogenase (11ß-HSD) inhibition in vitro. Only mauritine A (7) showed inhibitory activity on 11ß-HSD1, with IC50 values of 52.0 (human) and 31.2 µg/mL (mouse).

Biologically active arborinane-type triterpenoids and anthraquinones from Rubia yunnanensis.

Twelve new arborinane-type triterpenoids (1-12) and four new anthraquinones (13-16), together with 50 known compounds, were isolated from the roots of Rubia yunnanensis. The structures of 1-16 were elucidated by spectroscopic data analysis and chemical methods. All compounds were evaluated for their cytotoxic, antibacterial, and antifungal activities. Rubiyunnanol C (5) is the first example of an arborinane-type triterpenoid with a double bond at C-8-C-9.

[Flavonoids and nor-sesquiterpenes of Pedicularis densispica].

OBJECTIVE: To study the chemical constituents of the whole plants of Pedicularis densispica. METHOD: The chemical constituents were isolated by various chromatographic methods and their structures were determined by chemical evidences and spectral data. RESULT: Ten compounds were isolated and identified as acacetin (1), apigenin-7-0-beta-glucopyranoside (2), kaempferol-3,7-O-alpha-dirhamnopyranoside (3), scutellarein-7-0-beta-glucopyranoside (4), chrysoeriol-7-O-beta-glucopyranoside (5), pedicutricone A (6), dearabinosyl pneumonanthoside (7), salidroside (8), darendoside B (9), and maltol-beta-D-glucopyranoside (10). CONCLUSION: These compounds were isolated from the titled plant for the first time. Except compounds 6 and 8, the others were obtained for the first time from the genus Pedicularis.

[Chemical constituents from petroleum ether fraction of ethanol extract of Acorus tatarinowii].

The petroleum ether fraction of ethanol extract of Acorus tatarinowii were separated by column chromatography and recrystallization to afford seven compounds. On the spectroscopic analysis, they were identified as 1-hydroxy-7(11),9-guaiadien-8-one (1), calamenone(2), cis-asarone(3), chrysophanol (4), physcion (5), emodin (6), (+)-galbacin (7). Compound 1 is a new compound. Compounds 4-7 were isolated from this plant for the first time.

[Studies on chemical constituents in fruit of Alpinia oxyphylla].

OBJECTIVE: To study the chemical constituents in fruit of Alpinia oxyphylla and their cytotoxicities on cancer cell lines. METHOD: Compounds were isolated and purified by various column chromatographic methods. Their structures were determined by physico-chemical properties and spectral analyses. Compound cytotoxicity was assessed by the sulforhodamine B (SRB) assay. RESULT: Eight compounds were obtained from Me2CO-H2O (70%) extract of the fruit of A. oxyphylla and their structures were identified as: (9E)-humulene-2, 3; 6, 7-diepoxide (1), 3(12), 7(13), 9(E)-humulatriene-2, 6-diol (2), (-)-oplopanone (3), yakuchinone A (4), yakuchinone B (5), tectochrysin (6), isovanillin (7), (2E, 4E)-6-hydroxy-2, 6-dimethylhepta-2, 4-dienal (8), and the cytotoxicities of compounds 1, 3-5 on cancer cell lines, A549, HT-29 and SGC-7901, were also investigated. CONCLUSION: Compounds 1-3, 7, 8 were isolated for the first time from this genus and compounds 1, 3-5 exhibited no cytotoxicity against three cancer cell lines at a concentration of 10 mg x L(-1).

Apoptosis inducement of bigelovin from Inula helianthus-aquatica on human Leukemia U937 cells.

Inula helianthus-aquatica C. Y. Wu is a traditional medicinal plant used to treat some cancers in folk herbal medicine of Yunnan, China. Bigelovin, a sesquiterpene lactone isolated from this herb, potently inhibits the growth of a panel of eight cancer cell lines, especially in human monoblastic leukemia U937 cells with an IC(50) value of 0.47 microM. Characteristic morphological features of apoptosis were observed in U937 cells treated with bigelovin. Annexin V and nuclear DNA content distribution assays showed that the percentage of Annexin V positive cells increased to 8.86% (24 h) with 1 microM bigelovin treatment, and cells treated with bigelovin at this concentration apparently arrested at G(0)/G(1) phase compared with the control. These data suggested that cytotoxic effect of bigelovin on U937 cells involves induction of apoptosis, and the cell cycle is arrested at G(0)/G(1) phase.

Natural inhibitors of DNA topoisomerase I with cytotoxicities.

DNA Topoisomerase I can cause DNA breaks and play a key role during cell proliferation and differentiation. It is an important target for anticancer agents. While screening for anticancer compounds, seven natural compounds, 1-7, showed potent cytotoxicities against a panel of ten cancer cell lines. Moreover, an inhibition assay demonstrated that they are also DNA topoisomerase I inhibitors, in which inhibitors 1-5 are new ones.

3D-QSAR study of sulfonamide inhibitors of human carbonic anhydrase II.

3D-QSAR models of Comparative of Molecular Field Analysis (CoMFA) and Comparative of Molecular Similarity Indices Analysis (CoMSIA) of 61 potent carbonic anhydrase II (CAII) sulfonamide inhibitors were performed using two methods. The conventional ligand-based 3D-QSAR studies were performed based on the lower energy conformations employing database alignment rule. The receptor-based 3D-QSAR models were also derived using bioactive conformations obtained by docking compounds to the active sites of CAII. The receptor-based model gave q(2) values of 0.623 and 0.562, r(2) values of 0.986 and 0.987 for CoMFA and CoMSIA, respectively, which were much better than those of ligand-based model (q(2) values of 0.532 and 0.466). The predictive ability of the models was validated using the test set of 10 compounds that were not included in the training set of 51 compounds. Results of CoMFA and CoMSIA suggested that heterocyclic sulfonamides are more active than aromatic sulfonamides, in the latter 1,3,5-triazole group substituting one hydrogen atom of the amido is favored and moderate groups in its 4- and 6-position are required. These results provided further understanding of the relationship between the structural features of CAII and its activities, which should be applicable to design and find new potential CAII inhibitors.