Biosynthesis of the allene (-)-marasin in Marasmius ramealis.

[1-14C]-E-dehydromatricaria methyl ester and dimethyl [1-14C]-deca-4,6,8-triyne-1,10-dioate are incorporated into the allene (-)-marasin in Marasmius ramealis without scrambling of the 14C label. This and the levels of the incorporations (0.8% and 4.9% respectively) strongly suggests that the above esters, or close relatives, can be converted directly into (-)-marasin in M. ramealis, and that the diyne-allene moiety in this latter compound arises by the rearrangement, under enzymic control, of an alkyltriyne moiety.