Iminolactones from <i>Schizophyllum commune</i>

Schizines A (<b>1</b>) and B (<b>2</b>), the first naturally occurring iminolactones (3,6-dihydro-2<i>H</i>-1,4-oxazin-2-one derivatives) to be reported, have been isolated from the fruiting bodies of <i>Schizophyllym commune</i>. In principle the 2-oxazinone moiety might have been formed by a reaction between the amino acid phenylalanine or tryptophan and an 2α-hydroxy-1-ketomarasmone. The alkaloids are unusual in that the carboxyl group of the amino acid precursor is preserved during the biosynthesis. The compounds showed some inhibition of the growth of cancer cells.