Chang-u Ji

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.

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 IC50 value of 0.47 µM. 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 µM bigelovin treatment, and cells treated with bigelovin at this concentration apparently arrested at G0/G1 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 G0/G1 phase. Copyright

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.

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.

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.

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 11β-hydroxysteroid dehydrogenase (11β-HSD) inhibition in vitro. Only mauritine A (7) showed inhibitory activity on 11β-HSD1, with IC₅₀ values of 52.0 (human) and 31.2 μg/mL (mouse).

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.

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.