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Two new diketopiperazine metabolites, novoamauromine (1) and ent-cycloechinulin (2) have been isolated from Aspergillus novofumigatus CBS117520. The structures of 1 and 2 were established on the basis of spectroscopic and chemical investigation, including a detailed comparison of the spectroscopic and physico-chemical data of amauromine (3) and cycloechinulin (4).

In the course of searching for bioactive substances, two new dioxopiperazine derivatives, arestrictins A (1) and B (2), were isolated along with the known dioxopiperazine, cristatin A (3), and the known peptide, asperglucide (4), from the organic extract of the xerophilic fungi, Aspergillus restrictus and Aspergillus penicilloides. The absolute structures of 1 and 2, except for the configuration of the secondary alcohol in 1, were established by spectroscopic and chemical investigation. The absolute configuration of cristatin A (3) was also determined.

Three new type indoloditerpenes, emindoles PA (1), PB (2), and PC (3), were isolated from the mycelium of Emericella purpurea along with the sesterterpenes variecolol and variecolactone, and the dicyanide derivatives epurpurins A to C. The structures of 1-3 were confirmed by the spectroscopic investigation. The structure of emindoles PA (1) was revised from our preliminary report. Emindoles PA (1), PB (2), and PC (3) are the indoloditerpenes having a new type of carbon skeleton.

In the course of our research for new antifungal agents, two new meroterpenoids, penisimplicin A (1) and B (2), were isolated from Penicillium simplicissimum. The absolute structures of 1 and 2 were established by spectroscopic and chemical investigation. Penisimplicin A (1) and B (2) are rare examples of D-ring seco-meroterpenoids. Since compounds 1 and 2 showed no antifungal activities, the isolation of the compounds with antifungal activity will be attempted.

In the course of searching for new antifungal agents, a new pentanorlanostane derivative, cladosporide A (1), was isolated along with ergosterol, ergosterol peroxide and 23,24,25,26,27-pentanorlanost-8-ene-3beta,22-diol (2) from Cladosporium sp. as a characteristic antifungal agent against the human pathogenic filamentous fungus Aspergillus fumigatus. The structure of 1 was established as 3beta,22-dihydroxy-23,24,25,26,27-pentanorlanostane-29-al by spectroscopic and chemical investigation and X-ray crystallographic analysis. Inhibitory activity against A. fumigatus (IC80 0.5-4.0 microg/ml) was observed for cladosporide A (1), but no activity was observed against pathogenic yeasts, Candida albicans and Cryptococcus neoformans, and other pathogenic filamentous fungi, Aspergillus niger and A. flavus. The 4beta-aldehyde residue in 1 might be essential for the antifungal activity, since 23,24,25,26,27-pentanorlanost-8-ene-3beta,22-diol (2) showed no inhibition against the above four fungi.