Recently more than ten hybrid strains have been produced by means of cell fusion technique using two different strains IFO 6200 and 4692, and many interesting metabolites have been obtained from the mycelia of the hybrid strains ME 0005, KO 0011, KO 0031, and KO 0052. We wish to report the isolation and structure determination of ten new curvlarin-type compounds, six new sesterterpene-type compounds, two new pyrones with long side chains and a new indol-type alkaloid. These structures have been elucidated by means of spectroscopic analyses, some chemical evidence, X-ray cystallographic analyses and/or molecular mechanics calculation. ^<13>C-NMR analysis of the curvlarin-type metabolites obtained by feeding experiments with sodium [1,2-^<13>C_2] acetate showed that the curvlarin-type metabolites are produced from eight molecules of acetic acid as same as curvlarin and dehydrocurvularin. In these metabolites, furthermore, the carbon atom (C_<12>)bearing the oxygen function is originally derived from the methyl group of acetate molecule, clealy indicating that they are not formed in such a β-oxidation manner as seen in dehydrocurvularin, but directly formed by enzymatic oxygenation from such a less oxidized precursor as curvularin. Especially, compound 27 has been found to have the high potent antifeedant activity against Plutella xylostella.
