Peniterpenoids A-C, new sesquiterpenoid metabolites from a wheat cyst nematode Penicillium janthinellum.

Three new sesquiterpenoids, peniterpenoids A - C (1-3), together with six known metabolites (4-9) were isolated from an entomogenous fungus Penicillium janthinellum (LB1.20090001) collected from a wheat cyst nematode. The structures of the new compounds were elucidated based on NMR and HRESIMS spectroscopic analyses. The absolute configuration of the C-8 secondary alcohol of peniterpenoid B (2) was determined by [Rh2(OCOCF3)4]-induced ECD experiment. Subsequently, the antimicrobial and DPPH scavenging activities were determined. Compounds 6-8 exhibited moderate antibacterial activities against Staphylococcus aureus (CGMCC1.2465) with MIC values of 25.0, 50.0 and 12.5 µg/mL, respectively.

Cordycepamides A-E and cordyglycoside A, new alkaloidal and glycoside metabolites from the entomopathogenic fungus Cordyceps sp.

Five new alkaloidal metabolites cordycepamides A-E (1-5), and one glycoside metabolite cordyglycoside A (6), together with six known compounds (7-12) were isolated from the entomopathogenic fungus Cordyceps sp. (LB1.18060004) from unidentified insect collected in Baoshan City, Yunnan Province, People's Republic of China. The structures were characterized by NMR and HRESIMS spectroscopic analyses. Cordycepamides A and B (1 and 2) were mixtures of two isomers in 5:4 ratio by integration of 1H NMR spectra. In additional, the structure of cordycepamide A (1) was further confirmed by X-ray crystallography as a pair of enantiomers. Absolute configurations of sugar moiety of cordyglycoside A (6) was confirmed by the acid hydrolysis and subsequent HPLC analysis. The isolated metabolites were evaluated for antimicrobial, cytotoxicity, and the DPPH scavenging assay, only 4 showed modest antioxidant effects in the DPPH scavenging assay (IC50 = 51.42 ± 3.08 µM).

Botryane Sesquiterpenoids, Cyclopentadepsipeptides, Xanthones, and Trichothecenes from Trichoderma oligosporum.

Five new botryane sesquiterpenes (1: -5: ), one new cyclopentadepsipeptide (9: ), and two new xanthones (11:  - 12: ), together with 11 known compounds, were isolated from Trichoderma oligosporum. The structures of the new compounds were identified by comprehensive spectroscopic methods including nuclear magnetic resonance and mass spectrometry. The cytotoxicity of 1: -19: was evaluated against K562, A549, and ASPC cell lines. Compounds 5, 8, 11, 17: , and 18: showed cytotoxicity against the K562 cell line with more than 50% inhibition at 12.5 µM. As to A549 cell line, compound 8: showed the strongest cytotoxicity with approximately 50% inhibition at 25.0 µM. No compounds showed cytotoxicity against the ASPC cell line.

Characterization of a Prenyltransferase for Iso-A82775C Biosynthesis and Generation of New Congeners of Chloropestolides.

Chloropupukeananin and chloropestolides are novel metabolites of the plant endophyte Pestalotiopsis fici, showing antimicrobial, antitumor, and anti-HIV activities. Their highly complex and unique skeletons were generated from the coisolated pestheic acid (1) and iso-A82775C (10) based on our previous studies. Here, we identified the biosynthetic gene cluster iac of 10 and characterized an iacE encoded prenyltransferase. Deletion of iacE abolished iso-A82775C production, accumulated the prenyl group-lacking siccayne (2), and generated four new chloropestolides (3-6). Compounds 5 and 6 showed antibacterial effects against Staphylococcus aureus and Bacillus subtilis, and 5 was also cytotoxic to human tumor cell lines HeLa, MCF-7, and SW480. These results provided the first genetic and biochemical insights into the biosynthesis of natural prenylepoxycyclohexanes and demonstrated the feasibility for generation of diversified congeners by manipulating the biosynthetic genes of 10.

Coniochaetones E-I, new 4H-chromen-4-one derivatives from the Cordyceps-colonizing fungus Fimetariella sp.

Five new 4H-chromen-4-one derivatives coniochaetones E-I (1-5), along with the known compounds coniochaetones B (6) and A (7) have been isolated from solid cultures of the Cordyceps-colonizing fungus Fimetariella sp. Their structures were elucidated primarily by NMR spectroscopy and the absolute configurations of compounds 1-3 were assigned using the modified Mosher's method. Compound 4 showed weak cytotoxic activity against HeLa cells with IC50 values of 72.8 µM. The co-isolated known compound 6 showed modest inhibitory effects against Aspergilus fumigates, Fusarium oxysporum and Fusarium nivale.

Two new imidazolone-containing alkaloids and further metabolites from the ascomycete fungus Tricladium sp.

Tricladins A and B (1 and 2, resp.), new imidazolone-containing alkaloids, together with five known metabolites, bacillamides A, B (3 and 4, resp.), 20-hydroxyaflavinine (5), N-(2-phenylethyl)acetamide (6), and N(b)-acetyltryptamine (7), have been isolated from the crude extract of the ascomycete fungus Tricladium sp. The structures of 1 and 2 were elucidated primarily by NMR and MS methods. Compound 2 showed marginal cytotoxicity against MDA-MB-231 human breast cancer cells, whereas the known metabolite 4 displayed an inhibitory effect on HIV-1 replication in C8166 cells.

Labdane diterpenoid glycosides from Aster veitchianus.

Four new labdane-type rhamnopyranosides derived from 13-epimanool, compounds 1-4, with differently acetylated sugar moieties, were isolated from A. veitchianus. Their structures and absolute configurations were elucidated by chemical transformation, spectroscopic and mass-spectrometric analyses (IR, 1D- and 2D-NMR, HR-ESI-MS), as well as by single-crystal X-ray diffraction (compound 1). The isolates 2-4 were investigated for their cytotoxic properties against cultured human hepatoma (SMMC-7721), ovarian neoplasm (HO-8910), and leukemia (HL-60) cells, and for their antibacterial activities against Escherichia coli, Bacillus subtilis, and Staphylococcus aureus.

New eremophilenolides from Cacalia pilgeriana.

Five new eremophilenolides and a known sesquiterpene were isolated from the methanol extract of the roots of Cacalia pilgeriana. Their structures were identified as 1 beta-hydroxy-2 beta-methyl-senecioyloxyeremophil-7(11)-en-8 beta(12)-olide (1), 1 beta-hydroxy-2 beta-methylsenecioyloxy-8 alpha-methoxyeremophil-7(11)-en- 8 beta(12)-olide, 2 beta-hydroxy-3 beta-methylsenecioyloxyeremophil-7(11)-en-8 alpha(12)-olide ( 3), 2 beta,8 beta-dihydroxy-3 beta-methylsenecioyloxyeremophil-7(11)-en-8 alpha(12)-olide and 1 beta,8 beta-dihydroxy-2 beta,3 alpha-diangeloyloxyeremophil-7(11)-en-8 alpha(12)-olide ( 5) and caryolane-1,9 beta-diol by spectroscopic methods including 2D-NMR techniques ( (1)H- (1)H COSY, HMQC, HMBC) and HR-ESI-MS. The structure and relative stereochemistry of compound 1 were unequivocally established by X-ray diffraction analysis. Bioassays showed compounds 3 and 5 to possess strong cytotoxic activity in vitro against human leukemia cells (HL-60) (IC (50) < 15 microg mL (-1)). The structure-activity relationship is discussed.