Trimeric Hemibastadin Congener from the Marine Sponge Ianthella basta
The first naturally occurring trimeric hemibastadin congener, sesquibastadin 1 (1), and the previously reported bastadins 3, 6, 7, 11, and 16 (2-6) were isolated from the marine sponge Ianthella basta, collected in Indonesia. The structure of 1 was elucidated on the basis of 1D and 2D NMR measurements and by HRMS. Among all the isolated compounds, the linear sesquibastadin 1 (1) and bastadin 3 (2) showed the strongest inhibition rates for at least 22 protein kinases (IC(50) = 0.1-6.5 μM), while the macrocyclic bastadins (3-6) demonstrated a strong cytotoxic potential against the murine lymphoma cell line L5178Y (IC(50) = 1.5-5.3 μM).
Aaptamine Derivatives from the Indonesian Sponge Aaptos suberitoides
Four new aaptamine derivatives (1-4) along with aaptamine (5) and three related compounds (6-8) were isolated from the ethanol extract of the sponge Aaptos suberitoides collected in Indonesia. The structures of the new compounds were unambiguously determined by one- and two-dimensional NMR and by HRESIMS measurements. Compounds 3, 5, and 6 showed cytotoxic activity against the murine lymphoma L5178Y cell line, with IC(50) values ranging from 0.9 to 8.3 μM.
Farinomalein derivatives from an unidentified endophytic fungus isolated from the mangrove plant Avicennia marina
Five farinomalein derivatives including three new compounds, farinomaleins C–E (3–5), and one new isoindoline congener (6) were isolated from an unidentified endophytic fungus obtained from the inner tissues of healthy leaves of the mangrove plant Avicennia marina from Oman. The structures of the new compounds were unambiguously elucidated on the basis of their mass, as well as one and two dimensional NMR spectroscopic data.
Bioactive polyketides and alkaloids from Penicillium citrinum , a fungal endophyte isolated from Ocimum tenuiflorum
Chemical investigation of the endophytic fungus Penicillium citrinum cultured on white beans or on rice led to the isolation of two new alkaloids (1 and 2), along with fourteen known polyketides (6-12, 14-20) and four known alkaloids (3-5, and 13). The structures of the isolated compounds were determined by extensive analysis of the 1D, 2D NMR, and MS data, and by comparison with the literature. Compound 13, which had been previously obtained only by chemical synthesis, was isolated as a natural product for the first time, while compound 6 was firstly reported as a fungal metabolite. A re-isolation of sclerotinin A (14) revealed it to be a diastereoisomeric mixture (14a and 14b), whose ster…