Mitoguazone (31959-87-2) is a potent and reversible inhibitor of S-adenosylmethionine decarboxylase (SAMD or AdoMetDC).^1,2 SAMD is a component of the polyamine-biosynthetic pathway, thus inhibition may lead to changes in polyamine metabolism.³ Mitoguazone has also been shown to inhibit diamine oxidase and induce spermidine/spermine N-acetyltransferase.^4,5 Mitoguazone has been looked at as a potential anti-cancer treatment because of it's ability to inhibit polyamine synthesis.⁶

References/Citations
1) Wiliams et al., (1971), Methylglyoxal bis(guanylhydrazone) as a potent inhibitor of mammalian and yeast S-adenosylmethionine decarboxylases; Biochem. Biophys. Res. Commun., 46 288
2) Corti et al., (1974), Specific inhibition of enzymic decarboxylation of S-adenosylmethionine by methylglyoxal bis(guanylhydrazone) and related substances; Biochem. J., 139 351
3) Williams-Ashman and Seidenfeld, (1986), Aspects of the biochemical pharmacology of methylglyoxal bis(guanylhydrazone); Biochem. Pharmacol., 35 1217
4) Janne and Morris, (1984), Inhibition of S-adenosylmethionine decarboxylase and diamine oxidase activities by analogues of methylglyoxal bis(guanylhydrazone) and their cellular uptake during lymphocyte activation; Biochem. J., 218 947
5) Pegg et al., (1985) Induciton of spermidine/spermine N-acetyltransferase by methylglyoxal bis(guanylhydrazone); Biochim. Biophys. Acta, 842 111
6) Porter and Janne (2012) Modulation of Antineoplastic Drug Action by Inhibitors of Polyamine Biosynthesis. In Inhibition of polyamine metabolism: Biological Significance and Basis for new Therapies; McCann, Ed.; Elsevier; pp.203-248