Secondary metabolites from the Cordyceps-colonizing fungus Aspergillus versicolor ZJUTE2.

Two new polyketides versicolorones A-B (1-2), one new diketopiperazine derivative aspergiamide B methyl ester (3), along with twenty known compounds 4-23, were obtained from the EtOAc extract of the Cordyceps-colonizing fungus Aspergillus versicolor ZJUTE2. The structures of 1-3 were established by detailed interpretation of the spectroscopic data and their absolute configurations were established by comparative analyses of the calculated and experimental ECD spectra. In the in-vitro bioassay, compounds 8 and 21 exhibited significant inhibitory activity against the Escherichia coli ß-glucuronidase (EcGUS) with IC50 values of 54.73 ± 2.69 and 56.59 ± 1.77 µM, respectively.

Induced production of a new polyketide in Penicillium sp. HS-11 by chemical epigenetic manipulation.

Chemical investigation into the culture broth of the plant endophyte Penicillium sp. HS-11 in the modified Martin's medium supplemented with subemylanilide hydroxamic acid (SAHA), a well-known histone deacetylase (HDACs) inhibitor, led to the isolation and identification of two induced products 4-epipenicillone B (1) and (R)-(+)-chrysogine (2). 4-epipenicillone B (1) was obtained as a new compound whose structure was elucidated by comprehensive spectroscopic methods including 1 D/2D NMR, HRESMS, and quantum chemistry calculations including DFT GIAO 13C NMR and ECD calculation. Acquisition of 4-epipenicillone B (1) enriched the chemical diversities of fungal natural products possessing a tricyclo [5.3.1.03,8] undecane skeleton. The cytotoxic activity of 1 was also evaluated.

Spiroinonotsuoxotriols A and B, Two Highly Rearranged Triterpenoids from Inonotus obliquus.

Spiroinonotsuoxotriols A (1) and B (2), two highly rearranged pentacyclic triterpenoids featuring a novel 7(8 → 9)abeo-21,24-cyclo-lanostane skeleton, together with their proposed precursors 3-5, were isolated from the sclerotia of the white-rot fungus Inonotus obliquus. Their structures including the absolute configurations were elucidated by extensive spectroscopic analyses and single-crystal X-ray diffraction. The biogenetic pathway of 1 and 2 was proposed. Compounds 1 and 2 exhibited potent α-glucosidase inhibitory activity as compared with the positive control acarbose.

Biotransformation of Huperzine A by Irpex lacteus-A fungal endophyte of Huperzia serrata.

The biotransformation of huperzine A (hupA), one of the characteristic bioactive constituents of the medicinal plant Huperzia serrata, by a fungal endophyte of the host plant was studied. Two previously undescribed compounds 1-2, along with a known analog 8α,15α-epoxyhuperzine A (3), were isolated and identified. The structures of all the isolates were established by spectroscopic methods including NMR, MS, IR, and UV spectra. In particular, the absolute configurations of 1 and 2 were elucidated by CD spectra comparison and theoretic NOE strength calculation. In the LPS-induced neuro-inflammation injury assay, 1-3 exhibited moderate neuroprotective activity by increasing the viability of U251 cell lines with EC50 values of 35.3 ±â€¯0.9, 32.1 ±â€¯0.9, and 50.3 ±â€¯0.8 nM, respectively.