N 5-(4-hydroxybenzyl) glutamine has been isolated from Sin& alba L. and S. aruensis L. The identification is based on data obtained by HPLC, paper chromatography, high voltage electrophoresis, UV and NMR spectroscopy of the amide and its degradation products. The amide occurs together with 4-hydroxybenzylamine and sinalbin in both seeds and seedlings of the Sinapis species. This co-occurrence is briefly discussed in relation to chemotaxonomy, glucosinolate catabolism and amine metabolism.