Isolation of some new tryptoquivaline-related metabolites from Aspergillus fumigatus

The structures of tryptoquivaline L, M and N, which were newly isolated from the fungus, Aspergillus fumigatus, have been elucidated as 1, 3 and 11, respectively. Concomitantly, the previously proposed structures of tryptoquivaline C (9) and D (4) have been revised to 10 and 8. The exchange of the hydrogen on C-12 during epimerization of the dextrorotatory tryptoquivalines was demonstrated by means of a deuterium NMR spectral study.