Two New Indolyl Diketopiperazines, Trypostatins C and D from Aspergillus penicilliodes Speg.

Twelve indolyl diketopiperazines 1–12 were isolated from the mycelia culture of Aspergillus penicilliodes Speg., a dominant microorganism from the post fermentation process of ripe Pu-er tea. Their structures were elucidated by extensive spectroscopic methods. Among them, trypostatins C (1) and D (2) featuring with a rare methyl vinyl ketone side chain at C-2 are new compounds, while 3 and 4 were obtained for the first time from nature source. The isolates 3–12 did not show obvious cytotoxicities against five human cancer cell lines at a concentration of 40 μM. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13659-018-0156-z) contains supplementary material, which is available to authorized users.