Cheng-Xiong Liu

Five new furostanol saponins from the rhizomes of Tupistra chinensis

Five new furostanol saponins (1-5), together with three known compounds (6-8) were obtained from the n-butanol soluble fraction of ethanol extract from Tupistra chinensis. Their structures were determined on the basis of chemical methods and spectral data. The isolated compounds were tested in vitro for their cytotoxic activities against the A549, HepG 2 and Caski cancer cell lines. Among them, compounds 6, 7, and 8 showed cytotoxicity against A549 cancer cell lines with IC(50) values of 6.6, 6.7 and 29.1 μM, respectively.

Tupisteroide A–C, three new polyhydroxylated steroidal constituents from the roots of Tupistra chinensis

Three new steroidal compounds with polyhydroxy groups, tupisteroide A–C (1–3), were obtained from the roots of Tupistra chinensis, together with one known compound (4) that was isolated from this plant for the first time. The structures of tupisteroide A–C were determined on the basis of one‐ and two‐dimensional NMR spectroscopy, including 1H–1H Correlation Spectroscopy, Heteronuclear Multiple Bond Correlation, and Heteronuclear Single Quantum Coherence experiments. The isolated compounds were evaluated for their cytotoxic activities against A549, HepG2, and CaSki cancer cell lines in vitro. Among them, compounds 1, 2, and 4 did not show significant inhibitory activity, but compound 3 showed cytotoxicity against A549 cancer cell lines with IC50 values of 25.0 μM. Copyright

Two new steroidal glycosides with unique structural feature of 14α-hydroxy-5β-steroids from Reineckia carnea

Two new steroidal glycosides (1-2) were isolated from the roots of Reineckia carnea, together with three known compounds (3-5). Their structures were determined on the basis of chemical methods and spectral data. Compounds 1-2 were the unique steroidal glycosides possessing structural feature of 14α-hydroxy-5β-steroids, and compounds 4-5 were isolated from R. carnea for the first time. The isolated compounds (1-5) were tested in vitro for their cytotoxic activities against the A549, HepG 2 and Caski cancer cell lines. Among them, the compounds 2 and 3 showed cytotoxicity against Caski cancer cell line with IC50 values of 34.4 and 3.7μM, respectively.

Germacrane-Type Sesquiterpenoids with Antiproliferative Activities from Eupatorium chinense

Ten new germacrane-type sesquiterpenoids (1-10) were isolated from a whole plant extract of Eupatorium chinense. The structures were elucidated by analysis of their NMR and MS data as well as by comparison with literature values. The absolute configuration of eupachinsin A (1) was determined by single-crystal X-ray diffraction analysis. Compounds 3 and 4 exhibited cytotoxicity against a human breast cancer cell line (MDA-MB-231), with IC50 values of 0.8 and 3.4 μM, respectively. In addition, compounds 3-5 showed cytotoxicity against the human hepatocellular carcinoma cell line (HepG2), with IC50 values ranging from 3.6 to 7.6 μM.

Caroguaianolide A–E, five new cytotoxic sesquiterpene lactones from Carpesium abrotanoides L.

Five new guaiane-type sesquiterpene lactones, caroguaianolide A-E (1-5), along with nine known sesquiterpene lactones (6-14) were isolated from the whole plant of Carpesium abrotanoides L. Their structures were elucidated on the basis of spectroscopic date, HRESIMS analysis, and comparison of experimental and calculated ECD data. All isolated compounds (1-14) were tested in vitro for their cytotoxic activities against the MDA-MB-231, HGC-27 cancer cell lines, of which compounds 1-3, 6, 7, 11 and 12 showed significant cytotoxic activities with IC50 values ranging from 2.67 to 12.34 μM.

Penicitroamide, an Antimicrobial Metabolite with High Carbonylization from the Endophytic Fungus Penicillium sp. (NO. 24)

Penicitroamide (1), a new metabolite with a new framework, was isolated from the ethyl acetate extract of the PDB (Potato Dextrose Broth) medium of Penicillium sp. (NO. 24). The endophytic fungus Penicillium sp. (NO. 24) was obtained from the healthy leaves of Tapiscia sinensis Oliv. The structure of penicitroamide (1) features a bicyclo[3.2.1]octane core unit with a high degree of carbonylization (four carbonyl groups and one enol group). The chemical structure of penicitroamide (1) was elucidated by analysis of 1D-, 2D-NMR and MS data. In bioassays, penicitroamide (1) displayed antibacterial potency against two plant pathogens, Erwinia carotovora subsp. Carotovora (Jones) Bersey, et al. and Sclerotium rolfsii Sacc. with MIC50 at 45 and 50 μg/mL. Compound 1 also showed 60% lethality against brine shrimp at 10 μg/mL. Penicitroamide (1) exhibited no significant activity against A549, Caski, HepG2 and MCF-7 cells with IC50 > 50 μg/mL. Finally, the possible biosynthetic pathway of penicitroamide (1) was discussed.

Aspergoterpenins A–D: Four New Antimicrobial Bisabolane Sesquiterpenoid Derivatives from an Endophytic Fungus Aspergillus versicolor

Aspergoterpenins A–D (1–4), four new bisabolane sesquiterpenoid derivatives, were obtained from the endophytic fungus, Aspergillus versicolor, together with eight known compounds (5–12), and their structures were elucidated by a comprehensive analysis of their NMR (Nuclear Magnetic Resonance), MS (Mass Spectrum) and CD (Circular Dichroism) spectra. Aspergoterpenin A (1) was the first example with a characteristic ketal bridged-ring part in the degraded natural bisabolane-type sesquiterpene structures. The compounds 1–12 displayed no significant activities against four cancer cell lines (A549, Caski, HepG2 and MCF-7). Further, the antimicrobial activities to Erwinia carotovora sub sp. Carotovora were evaluated, and the results showed that compounds 1–12 displayed antimicrobial activities with MIC values ranging from 15.2 to 85.2 μg/mL.

Structural elucidation and NMR spectral assignments of paraconfuranones I-M from the insect-associated fungus Paraconiothyrium brasiliense.

Furanones consisted of natural oxygenated heterocycles have been reported from various natural sources. Fungus-derived furanone metabolites include aspertetronins A-B and gregatins A-E isolated from Cephalosporium gregatum, graminin A from Cephalosporium gramineum, 704-I-704-IV from Aspergillus panamensis, penicilliols A-B from penicillium daleae K. M. Zalessky, huaspenones A-B from Aspergillus sp. XW-12, and graminin B from Paraconiothyrium sp. Microorganisms living within the insect inner gut system without causing diseases have proven to be potential sources of diverse chemical structures. In the course of our systematic researches on the utilization of Chinese herbs and fungal sources in Shennongjia Forest District, a National Natural Protection Region of China, a rare fungus Paraconiothyrium brasiliense was isolated from the gut of healthy Acrida cinerea collected from the aforementioned district. It should be noted that the genus Paraconiothyrium have rarely been chemically explored, some terpenoids and furanones had been reported to date. In the previous paper, we reported the isolation and structural elucidation of paraconfuranones A–H from the insectassociated fungus P. brasiliense. During the continual screening for bioactive furanone analogs, another five new furanones, paraconfuranones I–M (3–7), together with two known furanones (1–2) were obtained from the genus under different fermentation conditions. Furthermore, the neuroprotective activities of the isolated compounds 1–3 and 5–6 were evaluated by PC12 cell apoptosis induced by hydrogen peroxide, and the compound 3 exhibited significant neuroprotective activities. In this paper, we reported the isolation and complete assignments of H and C-NMR spectral data of compounds 1–7 by MS, 1D-NMR and 2D-NMR spectral analyses, and the neuroprotective activity evaluation of these compounds against hydrogen peroxideinduced PC12 cell damage.