<jats:p>The structure 2 is established for 5-deoxybostrycoidin, a new metabolite isolated from cultures of the fungus Nectria haematococca (Berk. and Br.) Wr., on the basis of physico-chemical data (MS, <jats:sup>1</jats:sup>H and <jats:sup> 13</jats:sup>C NMR, acetylation) and by reference to the known bostrycoidin 1.