Alternatones A and B, two polyketides possessing novel skeletons from entophyte Alternaria alternate L-10.

On our ongoing searching for bioactive natural products derived from entophytes, two polyketides possessing novel skeletons, alternatones A-B (1-2), were identified from the culture of Alternaria alternate L-10. Their structures were established by a combination of spectroscopic and single-crystal X-ray diffraction with Cu Ka radiation. Alternatone A (1) exhibited cytotoxic activity against human hepatoma carcinoma HepG-2 cell line. The putative biosynthetic pathways for compounds 1-2 were also proposed.

Proposing of fungal endophyte secondary metabolites as a potential inhibitors of 2019-novel coronavirus main protease using docking and molecular dynamics.

In this study, the inhibitory potential of 99 fungal derived secondary metabolites was predicted against SARS-CoV-2 main protease by using of computational approaches. This protein plays an important role in replication and is one of the important targets to inhibit viral reproduction. Among the 99 reported compounds, the 9 of them with the highest binding energy to Mpro obtained from the molecular docking method were selected for the molecular dynamic simulations. The compounds were then investigated by using the SwissADME serve to evaluate the compounds in terms of pharmacokinetic and druglikness properties. The overall results of different analysis show that the compound RKS-1778 is potentially more effective than others and form strong complexes with viral protease. It also had better pharmacokinetic properties than other metabolites, so predicted to be a suitable candidate as anti SARS-CoV-2 bioactive.Communicated by Ramaswamy H. Sarma.