Absolute stereostructures of cytotoxic metabolites, chaetomugilins A–C, produced by a Chaetomium species separated from a marine fish

Two phytotoxic azaphilone derivatives fromChaetomium globosum, a fungal endophyte isolated fromAmaranthus viridisleaves

“…Chaetomium globosum is a popular fungus found on damp building materials (McMullin et al 2013) and was previously isolated as an endophytic fungus from Ginkgo biloba (Ginkgoaceae) (Qin et al 2009), Viguiera robusta (Asteraceae) (Borges et al 2011) and the marine fish Mugil cephalus (Yamada et al 2008). The isolation of chaetomugilin D ( 1 ) from the fungal endophyte C. globosum was reported previously (Muroga et al 2008; Qin et al 2009).…”

Absolute stereostructures of chaetomugilins G and H produced by a marine-fish-derived Chaetomium species

“…This fermentation was carried out on twice the volume than that used in previous reports 6,7 to obtain minor metabolites. After incubation, the AcOEt extract of the culture filtrate was purified by bioassay-directed fractionation (cytotoxicities against the P388 cell line) using a stepwise combination of Sephadex LH-20, silica gel column chromatography and reversed-phase HPLC to afford chaetomugilins G (3), H (4) and chaetoviridin C (5), together with chaetomugilins A-F.…”

“…Treatment with p-TsOH of chaetomugilin A (1) in MeOH gave chaetomugilins B and C, as reported previously. 6,7 This time, the above reaction was carried out on the condition that more p-TsOH was used, which then resulted in 3 together with chaetomugilins B and C (Scheme 1). Product 3 was confirmed to be identical to natural 3 on the basis of IR, UV and NMR spectra and optical rotations.…”

“…Chaetomugilin H (4), which contained one oxygen atom less than 3, was assigned the molecular formula, C 24 H 29 ClO 6 . The general features of its UV, IR and NMR spectra (Table 3) (Table 3).…”

“…[1][2][3][4][5] As part of this endeavor, we conducted a search for antitumor compounds from a strain of Chaetomium globosum OUPS-T106B-6 that was originally isolated from the marine fish, Mugil cephalus, and reported six new cytotoxic metabolites designated as chaetomugilins A (1), B, C, D (2), E and F from the culture broth of this fungal strain. 6,7 These compounds are azaphilones and they have various bioactivities, including antimicrobial, nitric oxide inhibitory, gp120-CD4-binding inhibitory, monoamine oxidase inhibitory and platelet-derived growth factor-binding inhibitory activities. 7 An examination of a diseaseoriented panel of 39 human cancer cell lines (HCC panel) 8,9 suggested the possibility that the mode of action of chaetomugilins A (1), C and F might be different from that shown by any other anticancer drugs developed to date.…”