In the course of screening toxic mold metabolites, three metabolites named chaetoglobosin A (I), B (II), and C (III) were isolated from the mycelial extract of Chaetomium globosum. High-resolution mass spectrometry showed they share the same molecular formula C₃₂H₃₆O₅N₂ (observed m/e: 528.263 for I, 528.265 for II, 528.264 for III; calculated 528.262). This work focuses on the structures of I and II. IR spectra indicated functional groups including -NH, -OH, C=O, aromatic rings, and trans-CH=CH-. UV spectra, positive Ehrlich reaction, mass spectral peak at m/e 130, and NMR data confirmed an indole chromophore (tryptophan moiety). IR and NMR also suggested a γ-lactam group. Acetylation experiments revealed one secondary alcohol in I and two in II. Isomerization of I (via triethylamine or chloroform) yielded II and III; NMR comparison showed structural differences arising from epoxide cleavage at C-12-C-13 in I. Precise decoupling experiments and fragment analysis led to the proposed structures of I and II. These structures are analogous to cytotoxic metabolites (phomins, sygosporins, cytochalasins) but replace phenylalanine with tryptophan. Biosynthetic evidence (from one tryptophan, nine acetate-malonate units, and three C₁ units) supports the structures. Further confirmation, including stereochemistry, is ongoing.