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Bioassay-guided fractionation of a fungus Neocosmospora sp. (UM-031509) resulted in the isolation of three new resorcylic acid lactones, neocosmosin A (2), neocosmosin B (3), and neocosmosin C (4). Three known resorcylic acid lactones, monocillin IV (1), monocillin II (5), and radicicol (6), were also isolated and identified. The structures of these compounds were established on the basis of extensive 1D and 2D NMR spectroscopic analysis, mass spectrometric (ESIMS) data, and X-ray crystallography. Compounds 4-6 show good binding affinity for the human opioid receptors. These findings have important implications for evaluating the potential psychoactive effects with this class of compounds.

Bioassay-guided fractionation of the fungus Eurotium repens resulted in the isolation of two new benzyl derivatives, (E)-2-(hept-1-enyl)-3-(hydroxymethyl)-5-(3-methylbut-2-enyl)benzene-1,4-diol (1) and (E)-4-(hept-1-enyl)-7-(3-methylbut-2-enyl)-2,3-dihydrobenzofuran-2,5-diol (2), along with seven known compounds (3-9) including five benzaldehyde compounds, flavoglaucin (3), tetrahydroauroglaucin (4), dihydroauroglaucin (5), auroglaucin (6), and 2-(2',3-epoxy-1',3'- heptadienyl)-6-hydroxy-5-(3-methyl-2-butenyl)benzaldehyde (7), one diketopiperazine alkaloid, echinulin (8), and 5,7-dihydroxy-4-methylphthalide (9). The chemical structures of these compounds were established on the basis of extensive 1D and 2D NMR and HRMS data. Compounds 1-4 and 6 showed good binding affinity for human opioid or cannabinoid receptors. These findings have important implications for psychoactive studies with this class of compounds.

A new compound, euparvic acid (1, C(14)H(16)O(6)), and the known compounds 5,7-dihydroxy-4-methylphthalide (2), 6-(3-carboxybutyl)-7-hydroxy-5-methoxy-4-methylphthalan-1-one (3), 6-(5-carboxy-3-methylpent-2-enyl)-7-hydroxy-5-methoxy-4-methylphthalan-1-one (4), and 6-(5-carboxy-4-hydroxy-3-methylpent-2-enyl)-7-hydroxy-5-methoxy-4-methylphthalan-1-one (5) were isolated from the EtOAc extract of Eupenicillium parvum. The structure of 1 was determined by interpretation of MS and homo- and heteronuclear 2D NMR spectroscopic data and confirmed by X-ray crystallography. The absolute configuration of 5 was determined via MPA ester derivatization.

Botcinins E and F were isolated together with the known botcinolide. The structures of botcinins E and F were determined to be 3-O-deacetylbotcinin A (5) and 3-O-deacetyl-2-epi-botcinin A (6), respectively, by spectroscopic methods and chemical conversion. The structure of botcinolide was revised on the basis of spectroscopic data and chemical conversion. Botcinolide was originally reported as a nine-membered lactone (7), but the revised structure is the seco acid of botcinin E (13). Thus botcinolide is renamed botcinic acid, and homobotcinolide is renamed botcineric acid. Reinvestigation of the spectroscopic data reported for all botcinolide analogues indicates that 4-O-methylbotcinolide and 3-O-acetyl-2-epibotcinolide are the same as a methyl ester of botcinic acid (13a) and botcinin A (1), respectively, and that 2-epibotcinolide may be the same as botcinin E (5). Compounds 5, 6, and 13 showed weak antifungal activity against Magnaporthe grisea, a pathogen of rice blast disease.

Four new metabolites with carotane skeletons, trichocaranes A (1), B (2), C (3), and D (4), were isolated from Trichoderma virens and their structures established by the interpretation of NMR and mass spectroscopic data. The trichocaranes significantly inhibited the growth of etiolated wheat coleoptiles: 40% at 10(-4) M with 1 and 2 and 86% at 10(-3) M with 3.

A new metabolite, koninginin G (1), was isolated from a strain of Trichoderma aureoviride and its structure established by the interpretation of spectroscopic data. The metabolite significantly inhibited the growth of etiolated wheat coleoptiles by 56% at 10(-3) M.

Extraction of the fungus Cladosporium cladosporioides yielded the known isocoumarin, cladosporin [1], and a new compound. This metabolite, which inhibited the growth of etiolated wheat coleoptiles slightly more than did cladosporin, was characterized as a diastereoisomer of cladosporin at C-14 and was named isocladosporin [2].

An isolate of Fusarium heterosporum Nees ex Fr. that parasitizes the honeydew and immature sclerotia of Claviceps paspali was shown to be highly toxigenic to day-old chickens. The major toxicity of culture extracts of the fungus was due to the presence of several trichothecene mycotoxins. Six trichothecenes were isolated and chemically identified by spectroscopic methods as T-2 toxin (1), HT-2 toxin (2), T-2 tetraol (6), 3alpha,4beta,dihydroxy-15-acetoxy-8alpha-(3-hydroxy-3-methylbutyryloxy)-12,13-epoxytrichothec-9-ene (3), 3alpha,4beta,15-trihydroxy-8alpha-(3-hydroxy-3-methylbutyryloxy)-12,13-epoxytri chothec-9-ene (5), and 3alpha,4beta,8alpha-trihydroxy-15-acetoxy-12,13-epoxytrichothec-9-ene (4). The acute toxicities of the trichothecenes were compared to the effects of T-2 toxin in day-old chickens and on the back skins of rabbits. The comparative inhibitory effects of the trichothecene mycotoxins in the Triticum coleoptile bioassays were also determined.