Eight indole-containing metabolites (tentatively named FTA-H) have been isolated from Aspergillus fumigatus and the structures of two among them, fumitremorgins A and B(FTA and B) being strongly tremorgenic , have already been elucidated by us. I) The remaining six(FTC-H) have different chemical and spectral properties from that of FTA or-B and no detectable tremorgenic effect to the experimental animals. FTC(I), mp.215-217?,decomp) ,[$~+168?c=O.23, CHC13), C29H30N407(M:m/e 546) exhibits the absorption maxima at 228(39800) ,233(38000),255(21100) ,280(14200),307(4200) and 320 ( 2700) nm(&) in the uv spectrum. From the ir spectrum, the presence of hydroxyl, r-lactone , ester and amide groups in the structure is expected. The pmr spectral data on FTC are summarized in Table together with those of the other metabolites and an acetate. During our study on FTC structure is under way, Clardy et al. have reported the result of X-ray analysis on tryptoquivaline structure, 2) and the properties reported therein on that fungal metabolite suggest the close similarity of that to our FTC although two are not entirely identical. A direct comparison of FTC-acetate (II) with acetate of tryptoquivaline has shown their complete identity as a result. This indicates that FTC is an isomer of tryptoquivaline regarding the position of acetyl group. By treatment with alkali, I receives epimerization possibly at C-12 and the epimer further affords acetate(n) , amorph.#l24, 5 -199*, C 31 32 4 82> H N 0 , with Ac20/pyridine, which seems to be identical with the epimer-acetate from tryptoquivaline. mD(w), mp.224-2250(decomp) &$~+l&c=O.23, CHC13), C28H28N407( MTm/e 532) exhibits quite similar uv and ir spectra to those of I. Very equivalent signals are also observed in the pmr spectrum of IV comparing with those of I, although a doublet methyl( 1.56ppm) appears instead of two singlet methyls( 1.48ppm and 1.5Oppm) in the spectrum of I. Both I and IV are oxidized with Cr03/90% AcOH and afford the same product, compound A, mp. 154.5-157:[6i?D8+228ยฐ, C25H23N306(M:m/e 461.1583). The structure of compound A has been determined by the chemical and spectral studies as V. The fact suggests that I and N may have the similar structures