An EtOH extract of Cenchrus echinatus (sandbur grass) infected with Balansia obtecta, a fungal endophyte of the Clavicipitaceae, has yielded ergobalansine [1], a new ergot-type alkaloid. Ergobalansine is a peptide derivative of lysergic acid, but differs from other known ergopeptine alkaloids in that the characteristic proline residue has been replaced by an alanine residue. The structure of ergobalansine was determined by analysis of1Hnmr,13C nmr, and mass spectra of the parent compound and of the C-8 epimer (ergobalansinine [2]) and by comparison of these to spectra of the common ergopeptine alkaloids. © 1990, American Chemical Society. All rights reserved.