Quinazoline-Containing Indole Alkaloids from the Marine-Derived Fungus Aspergillus sp. HNMF114.

Seven new quinazoline-containing indole alkaloids (1-7) named aspertoryadins A-G, along with nine known ones (8-16), were isolated from the marine-derived fungus Aspergillus sp. HNMF114 from the bivalve mollusk Sanguinolaria chinensis. The structures of the new compounds were elucidated from spectroscopic data, X-ray diffraction analysis, ECD spectra analysis, and ECD calculations. Compound 1 bears an aminosulfonyl group in the structure, which is rarely encountered in natural products. Compounds 6, 7, and 13 exhibited quorum sensing inhibitory activity against Chromobacterium violaceum CV026 with MIC values of 32, 32, and 16 µg/well, respectively.

Indole-Diterpenoids with Protein Tyrosine Phosphatase Inhibitory Activities from the Marine-Derived Fungus Penicillium sp. KFD28.

Five new indole-terpenoids named penerpenes E-I (1-5), along with seven known ones (6-12), were isolated from the marine-derived fungus Penicillium sp. KFD28 from a bivalve mollusk, Meretrix lusoria. The structures of the new compounds were elucidated from spectroscopic data and ECD spectroscopic analyses. Compound 1 was assigned as an indole-diterpenoid with a unique 6/5/5/6/6/5/5 heptacyclic ring system. Compound 2 represents an indole-diterpenoid with a new carbon skeleton derived from paxilline by the loss of three carbons (C-23/24/25). Compound 3 contains an additional oxygen atom between C-21 and C-22 compared to paxilline to form an unusual 6/5/5/6/6/7 hexacyclic ring system bearing a 1,3-dioxepane ring, which is rarely encountered in natural products. Compounds 1, 2, 4, and 6 showed inhibitory activities against protein tyrosine phosphatase 1B (PTP1B) with IC50 values of 14, 27, 23, and 13 µM, respectively.