A new assay method for immunosuppressants with a tacrolimus (FK506)-like mode of action

Clavariopsins C-I, Antifungal Cyclic Depsipeptides from the Aquatic Hyphomycete Clavariopsis aquatica

Seven new cyclic depsipeptides, clavariopsins C-I (3-9), together with two known congeners, clavariopsins A and B (1 and 2), were isolated from the aquatic hyphomycete Clavariopsis aquatica. Their planar structures, which consist of nine amino acids and one α-hydroxy acid, were elucidated by NMR spectroscopy and HRESIMS. The absolute configurations were established by the advanced Marfey's method and chiral-phase HPLC analysis. Their antifungal and cytotoxic activities were evaluated against six plant pathogenic fungi (Botrytis cinerea, Magnaporthe oryzae, Colletotrichum orbiculare, Fusarium oxysporum, Alternaria alternata, and Aspergillus niger) and a cancer cell line (HeLa-S3), respectively. The majority of the compounds exhibited potent antifungal activity against the fungi tested (minimum inhibition dose = 0.01-10 μg/disk) and induced hyphal swelling in A. niger (minimum effective dose = 0.3-3 μg/disk), whereas the compounds exhibited no cytotoxicity toward the cancer cell line. The results suggest that the clavariopsins could be a promising class of antifungal agents.

Antifungal activity of crude extracts and fat-soluble constituents of Holotrichia diomphalia larvae

In this study, chemical compositions of fatty oils and bioactivity of crude extracts from Holotrichia diomphalia larvae as Chinese materia medica were investigated for the first time. The chemical compositions of the fatty oils were obtained by two different methods and determined by GC/MS. In total, the petroleum ether extract produced 21 compounds (96.3%) while the supercritical fluid extract produced six compounds (99.53%) for identification. The effect of petroleum ether and other crude extracts on Pyricularia oryzae was also examined. Results indicated that ethanol and petroleum ether extracts had excellent antifungal activities. These findings demonstrated that fatty oils from H. diomphalia larvae had great potential to be used as a source for natural health products.

Anti-tumor effects of Rubratoxin B on cell toxicity, inhibition of cell proliferation, cytotoxic activity and matrix metalloproteinase-2,9

Terrestrial fungi are a prolific source of metabolites with significant biological activities. Many important anticancer, antifungal and antibacterial chemotherapeutics are either microbial metabolites or semisynthetic derivatives. Investigating the metabolites of fungi may increase the chance of finding novel compounds. A bioassay-guided fractionation of soil fungus Penicillium purpurogenum fermentation, yielded the metabolite Rubratoxin B using morphological deformation of Pyricularia oryzae mycelia. Analysis by flow cytometry showed that Rubratoxin B inhibited the cell cycle progression of tsFT210 cells in the G2/M phase at the concentration of 24 microM. Cytotoxic activity analysis showed that Rubratoxin B has a cytotoxic activity and IC50 was 67.3 +/- 1.4 microM on human fibrosarcoma cell (HT1080), and Rubratoxin B exhibited inhibitory activities against matrix metalloproteinase (MMP)-2 and 9 on HT 1080 cells with an inhibitory rate of 61.5% and 74.7% at 30 microM, respectively.