ATS shares structural and functional properties with digoxin.

Molecular mass of ATS (A) or digoxin (B) identified by APCI method. Molecular masses shown are sodium adducts of ATS or digoxin (both, m/z 780). Insets depict the predominant peaks of ATS or digoxin with their respective retention times. (C) and (D) Tandem mass spectra of ATS and digoxin, respectively. The ionization products characteristic of the steroidal nucleus (m/z 390), mono- and bi-sugar (m/z 520 and 650, respectively) molecules are highlighted. (E) Wild-type S. pombe cells were treated with residual solvent, ATS, or digoxin for 6 h and stained with CFW. Arrowheads show aberrant septal/cell wall biogenesis. Bars = 5 µm. (F) Conidia from wild-type M. oryzae were germinated on agarose in the presence of residual solvent, ATS, or digoxin and stained with CFW after 4 h. Excess cell wall deposits are indicated with arrowheads. Bar = 10 µm.