File Name : suppl scheme 1.tiff

Caption : reaction of 6-(3,4-dimethoxyphenyl)-1,4-diaminohexa-2,5-diene with ethyl formimidate and base hydrolysis of acanthoine

File Name : suppl fig 1.tif

Caption : time course of acid promoted conversion of (6<i>s</i>)-5-formiminotetrahydrofolate (<b>2</b>) to 5,10-methenyltetrahydrofolate (<b>7</b>)

File Name : suppl fig 2.tif

Caption : beer’s law dose-response correlation for (6<i>rs</i>)-5,10-methenyltetrahydrofolate (<i>rs</i>-7) hydrochloride

File Name : suppl fig 3.tif

Caption : uv spectra from uplc/uv analysis of ampouled <b>2</b>.(a) representative uv spectrum for (6<i>s</i>)-5-formiminotetrahydrofolate (<b>2</b>); (b) representative uv spectrum for (6<i>rs</i>)-5,10-methenyltetrahydrofolate (<i>rs</i>-7)