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Six new prenylated polyhydroxy-p-terphenyl metabolites, named prenylterphenyllins A-C (1-3) and prenylcandidusins A-C (5-7), and one new polyhydroxy-p-terphenyl with a simple tricyclic C-18 skeleton, named 4''-dehydro-3-hydroxyterphenyllin (4), were obtained together with eight known analogues (8-15) from Aspergillus taichungensis ZHN-7-07, a root soil fungus isolated from the mangrove plant Acrostichum aureum. Their structures were determined by spectroscopic methods, and their cytotoxicity was evaluated using HL-60, A-549, and P-388 cell lines. Compounds 1 and 8 exhibited moderate activities against all three cell lines (IC50 1.53-10.90 μM), whereas compounds 4 and 6 displayed moderate activities only against the P-388 cell line (IC50 of 2.70 and 1.57 μM, respectively).

Four new alkaloids, including two new meleagrin analogs, meleagrin D (1) and E (2), and two new diketopiperazines, roquefortine H (3) and I (4), were isolated from a deep ocean sediment-derived fungus Penicillium sp. Meleagrin D (1) and E (2) possess unprecedented acetate-mevalonate-derived side chains on the imidazole moiety. These new meleagrins showed weak cytotoxicity against the A-549 cell line, whereas meleagrin B (5) and meleagrin (6), which were isolated previously from the same strain, induced HL-60 cell apoptosis or arrested the cell cycle through G 2 /M phase, respectively. The results indicate that the distinct substitutions on the imidazole ring significantly influence the cytotoxicity of the meleagrin alkaloids.

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Three prenylated indole alkaloids with a rare anti bicyclo-[2.2.2]diazaoctane core ring (5-7) were isolated from Aspergillus taichungensis. The structures including absolute configurations were elucidated based on NMR, X-ray, and CD methods. (+)-Versicolamides B and C (8-9) which contain a spiro-center, together with seven analogues (7, 10-15), were isolated as photoinduced conversion products of 6. Biological evaluation indicated that 6 and 7 exhibited significant cytotoxicities with IC50 values in the low micromolar range.