Cycasin

Cycasin is a phytotoxin found in cycads such as Cycas revoluta and Zamia pumila. Both plants are used to produce sago. The butterfly Eumaeus atala, whose larvae feed on Z. pumila, also contains the compound. The seeds of C. revoluta contain the highest level of the toxin.

It induces hepatotoxicity and Zamia staggers, a fatal nervous disease affecting cattle where they browse on the leaves or fruit of cycads.

The enzyme methyl-ONN-azoxymethanol beta-D-glucosyltransferase uses the two substrates UDP-glucose and methyl-ONN-azoxymethanol to produce UDP and cycasin.