Cultures of a fungicolous isolate of Sporormiella minimoides afforded two new polyketide metabolites which we have named sporminarins A (1) and B (2). The planar structures of 1 and 2 were elucidated by analysis of NMR and MS data, and by chemical methods. 1 exhibited significant antifungal activity against Aspergillus flavus. Keywords sporminarins, antifungal, Sporormiella minimoides IntroductionOur ongoing studies of mycoparasitic and fungicolous fungi have shown them to be excellent sources of new biologically active natural products [1ϳ4]. In the course of this ongoing project, we examined cultures of a fungicolous isolate of Sporormiella minimoides Ahmed & Cain (Sporormiaceae; NRRL 37629) that was obtained from a basidioma of Trametes hirsutum collected from a dead hardwood branch in a subalpine dry forest in Hawaii. The ethyl acetate extract obtained from solid-state fermentation cultures of S. minimoides exhibited antifungal activity against Aspergillus flavus. The extract was fractionated using silica gel column chromatography, and the resulting fractions were subjected to reversed-phase HPLC to yield two new metabolites, which we have named sporminarins A (1) and B (2). The known compound brocaenol A was also obtained, and was identified by comparison of NMR and MS data with literature values [5]. Details of the isolation, structure elucidation, and bioactivities of 1 and 2 are presented here. Results and DiscussionSporminarin A (1) was assigned a molecular formula of C 36 H 62 O 8 (six degrees of unsaturation) on the basis of NMR (Table 1) and HRESIMS data. 1 H NMR analysis of 1 in CDCl 3 gave poor spectra, with considerable overlap and broad signals, but spectra recorded in CD 3 OD were of much better quality. 1 H, 13 C NMR, and DEPT data for 1 revealed the presence of six olefinic protons, five oxymethines, six non-oxygenated methines, three nonoxygenated methylenes, and 11 methyl groups. These units accounted for 56 protons, indicating that the remaining six protons must be exchangeable. The methyl group 1 H NMR signals consisted of two olefinic methyl resonances lacking vicinal coupling, two aliphatic methyl singlets, six CH 3 -CH doublets, and one CH 3 -CH 2 triplet. The 13 C NMR spectrum of 1 revealed 35 discrete signals, one short of the expected count, suggesting that two of the signals were coincident. Only seven signals were distinguishable in the olefinic region of the 13 C NMR spectrum of 1, and the DEPT spectrum contained six of those signals, indicating that the overlapped signal must correspond to one of two nonprotonated olefinic carbons. also revealed the presence of two oxygenated quaternary sp 3 carbons, and an oxycarbonyl carbon (d C 179.9) that was presumed to be a carboxylic acid group, although chemical shift alone could not definitively rule out an ester unit [6]. Treatment of 1 with trimethylsilyldiazomethane yielded the corresponding methyl ester (COOCH 3 methyl signal at d H 3.69), thereby confirming the presence of the carboxylic acid group. Of the six degrees of uns...

Seven new aroyl uridine derivatives (kipukasins A-G; 1-7) were isolated from solid-substrate fermentation cultures of two different Hawaiian isolates of Aspergillus versicolor. The structures of compounds 1-7 were determined by analysis of NMR and MS data. The nucleoside portion of lead compound 1 was assigned as uracil-1-β-D-ribofuranoside by spectral comparison with an authentic standard. The bioactivity of the original A. versicolor extracts was accounted for mainly by the presence of the known metabolite sterigmatocystin, but kipukasins A and B showed modest activity in assays against gram-positive bacteria.Our continuing interest in mycoparasitic and fungicolous fungi as sources of new bioactive secondary metabolites 1-3 prompted us to investigate the chemistry of an isolate of Aspergillus versicolor (Vuill.) Tiraboschi (MYC-2236 = NRRL 35600). Although A. versicolor is known as a producer of mycotoxins and other compounds, 4,5 isolation of A. versicolor as a colonist of other fungi has not been previously reported to our knowledge. This isolate was obtained from a basidioma of Gandoderma australe found growing on a tree in a montane mesic forest in Hawaii, and was cultured by solid-substrate fermentation on rice. The crude extract of the resulting cultures showed significant antiinsectan activity. Sterigmatocystin 5 was encountered as a major component, and was responsible for the antiinsectan activity of the original crude extract. However, initial analyses indicated the presence of a set of major constituents unrelated to sterigmatocystin. Further investigation afforded five new nucleoside derivatives, which we named kipukasins A-E (1-5). At the same time, analysis of extracts from cultures of a different fungicolous isolate of A. versicolor (also from Hawaii, but from a different location) led to recognition of the presence of a similar set of compounds. Studies of this second isolate yielded two additional related compounds (kipukasins F and G; 6 and 7). Details of the isolation, structure elucidation, and stereochemical assignment of these metabolites are described here. Results and DiscussionThe crude EtOAc extract from cultures of A. versicolor NRRL 35600 was subjected to solvent partitioning, chromatography on Sephadex LH-20, and reversed phase HPLC to afford samples of sterigmatocystin and kipukasins A-E (1-5). Sterigmatocystin was identified by comparison of NMR and MS data to those of a previously isolated sample. The molecular formula of kipukasin A (1) was determined as C 21 H 24 N 2 O 10 (11 unsaturations) based on NMR and MS data. The 1 H NMR spectrum revealed the presence of a 1,2,3,5-tetrasubstituted benzene ring, a 1,2-disubstituted olefin (J = 8.1 Hz), four oxymethine protons, one oxymethylene unit, two methoxy groups, two aryl or acetyl methyl groups, and one exchangeable proton (δ H * To whom correspondence should be addressed. Tel: 319-335-1361. Fax: 319-335-1270 8.65). 13 C NMR data were consistent with these observations, and also indicated the presence of four carboxy or am...

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