Prenylated indole diketopiperazine alkaloids as phosphatase inhibitors from the marine-derived fungus Talaromyces purpureogenus.

Six previously undescribed prenylated indole diketopiperazine alkaloids, talaromyines A-F (1 − 6), were isolated from the marine-derived fungus Talaromyces purpureogenus SCSIO 41517. Their structures including absolute configurations were elucidated on the basis of comprehensive spectroscopic data including NMR, HR-ESI-MS, and electronic circular dichroism calculations, together with chemical analysis of hydrolysates. Compounds 1 − 5 represent the first example of spirocyclic indole diketopiperazines biosynthesized from the condensation of L-tryptophan and L-alanine. Compounds 2 and 4 − 5 showed selective inhibitory activities against phosphatases TCPTP and MEG2 with IC 50 value of 17.9–29.7 μM, respectively. Compounds 4 − 5 exhibited mild cytotoxic activities against two human cancer cell lines H1975 and HepG-2. Six undescribed prenylated indole diketopiperazine alkaloids, talaromyines A-F, were isolated from the marine-derived fungus Talaromyces purpureogenus. Their cytotoxicities and inhibitory activities against seven different protein tyrosine phosphatases were evaluated. [Display omitted] • Six undescribed prenylated indole diketopiperazine alkaloids were isolated from the marine-derived fungus Talaromyces purpureogenus. • Talaromyines A-E represent the first example of spirocyclic IDAs biosynthesized from the condensation of L-tryptophan and L-alanine. • The cytotoxicity and phosphatase inhibitory activity were evaluated. [ABSTRACT FROM AUTHOR]