Zygosporin D

Fungal endophytes are sources of novel bioactive compounds but relatively few agriculturally important fruiting plants harboring endophytes have been carefully studied. Previously, we identified a griseofulvin-producing Xylaria species isolated from Vaccinium angustifolium, V. corymbosum, and Pinus strobus. Morphological and genomic analysis determined that it was a new species, described here as Xylaria ellisii. Untargeted high-resolution LC-MS metabolomic analysis of the extracted filtrates and mycelium from 15 blueberry isolates of this endophyte revealed differences in their metabolite profiles. Toxicity screening of the extracts showed that bioactivity was not linked to production of griseofulvin, indicating this species was making additional bioactive compounds. Multivariate statistical analysis of LC-MS data was used to identify key outlier features in the spectra. This allowed potentially new compounds to be targeted for isolation and characterization. This approach resulted in the discovery of eight new proline-containing cyclic nonribosomal peptides, which we have given the trivial names ellisiiamides A-H. Three of these peptides were purified and their structures elucidated by one and two-dimensional nuclear magnetic resonance spectroscopy (1D and 2D NMR) and high-resolution tandem mass spectrometry (HRMS/MS) analysis. The remaining five new compounds were identified and annotated by high-resolution mass spectrometry. Ellisiiamide A demonstrated Gram-negative activity against Escherichia coli BW25113, which is the first reported for this scaffold. Additionally, several known natural products including griseofulvin, dechlorogriseofulvin, epoxy/cytochalasin D, zygosporin E, hirsutatin A, cyclic pentapeptides #1-2 and xylariotide A were also characterized from this species.

Five new cytochalasans (1-5) were isolated from the rice fermentation of fungus Xylaria longipes, along with seven known compounds cytochalasin P (6), cytochalasin D (7), zygosporin D (8), 7-O-acetylcytochalasin D (9), cytochalasin C (10), 6,7-dihydro-7-oxo-cytochalasin C (11), and 6,7-dihydro-7-oxo-deacetylcytochalasin C (12). Their structures and absolute configurations were determined by extensive experimental spectroscopic methods as well as ECD calculation and GIAO 13C NMR calculation. The cytotoxicity of obtained compounds (1-12) was evaluated against human cancer cell lines HL-60, A549, SMMC-7721, MCF-7, and SW480. Compounds 6-8, 11, and 12 showed cytotoxicity with IC50 value ranging from 4.17-37.18 μM.

Objective: To seperate and identify the chemicals from the antitumor fraction of Cordyceps taii mycelia powder. Methods: The mycelia of Cordyceps taii were prepared by the submerged fermentation technique. Chemical entities in the antitumor fraction of Cordyceps taii were isolated and purified by using different column chromatographies (silica gel, Sephadex LH-20 and MCI), and semi-preparative HPLC method. Theirs chemical structures were then identified by different spectrum techniques such as EI, ESI and 1D/2D-NMR, etc. The cytotoxic activity was investigated by the Sulforhodamine B (SRB) assay. Results: Six compounds, such as 5α,8α-epidioxyergosta-6,22-dien-3β-ol (1), ergosterol (2), adenine nucleoside (3), helvolic acid (4), deacetylcytochalasin C (5) and zygosporin D (6), were identified. The IC50 value of compound 2 against human gastric cancer cell line SGC-7901 was 5.99 μmol/L, which was less than the half value of cisplatin, and had lower cytotoxicity to normal cells in comparison with cisplatin. Conclusion: Six compounds have been isolated from the antitumor fraction of Cordyceps taii mycelia powder,of which compounds 1, 5 and 6 are isolated from Cordyceps taii for the first time. Compounds 1, 2 and 4 have cytotoxic activities against cancer cells, and should be the main antitumor compounds of Cordyceps taii.