Emeheterone, a novel pyrazinone derivative, has been isolated from the culture filtrate of the fungus Emericella heterothallica, along with stellatin. Its molecular structure has been investigated by spectroscopic means. Natural abundance 13C NMR spectra were recorded of four naturally occurring 4-keto steroidal alkaloids, their acetylated derivatives, and of dihydrosolaphyllidine. The assignments were made with the help of APT spectra, based on chemical shifts arguments, and by comparison with the values reported for other steroidal alkaloids.