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Six new dibenzo[b,e]oxepinone metabolites, chaetones A-F (1-6), as well as three known compounds, 1-hydroxy-6-methyl-8-hydroxymethylxanthone (7), citreorosein (8), and emodin (9), were obtained from a freshwater-derived fungal strain Chaetomium sp. YMF 1.02105. Their structures were established on the basis of extensive spectroscopic data analysis and comparison with spectroscopic data reported. Compounds 1-6 are further additions to the small group of dibenzo[b,e]oxepinones represented by arugosins A-H. Compounds 1-7 were tested for their cytotoxic activities against A549, Raji, HepG2, MCF-7, and HL-60 cell lines. The results showed that compound 3 had significant cytotoxicity with IC50 values of 1.2, 1.8, 1.9, 2.3, and 1.6 µg/mL, respectively, against the five cancer cell lines. All compounds showed modest antimicrobial activity against Staphylococcus aureus (ATCC 6538) in standard disk assays., (Georg Thieme Verlag KG Stuttgart · New York.)

Two novel diastereoisomeric bicyclic ketals, colomitides A and B (1 and 2, resp.), together with the known (4RS)-3,4-dihydro-4,8-dihydroxynaphthalen-1(2H)-one (3) and preussomerin E (4), were isolated from liquid cultures of an unidentified freshwater fungus YMF 1.01029. Colomitides possess an unusual 2,7-dioxabicyclo[3.2.1]octane skeleton. The chemical structures and relative configurations of compounds 1 and 2 were elucidated by spectroscopic means, including 2D-NMR (HMBC, HMQC, TOCSY, ROESY, and (1)H,(1)H-COSY). Compounds 1, 2, and 4 showed noticeable antifungal and antibacterial activities.

Two novel naphthalene-containing compounds, colelomycerones A and B (1 and 2, resp.), and three known metabolites, including preussomerin D (3), (2RS,2'SR,3'E,3SR,4E,8E)-1-O-(beta-D-glucopyranosyl)-3-hydroxy-2-[(2-hydroxyoctadec-3-enoyl)amino]-9-methyloctadeca-4,8-diene (4), and 3beta-hydroxy-5alpha,8alpha-epidioxyergosta-6,22-diene (5), were isolated from the culture broth of an unidentified freshwater water fungus YMF 1.01029. This fungus was collected from a decaying branch of an unidentified tree near Lake Fuxian in Yunnan Province, China. The structures of these five compounds were determined on the basis of their spectroscopic and mass-spectrometric data. Colelomycerones A and B (1 and 2, resp.) represent unprecendented examples of naphthalene-1,2-diones with novel cyclic acetals. Compounds 1-3 showed noticeable antifungal and antibacterial activities.