How to reliably parse the correct gauge metabolite from the abomination format?

[MaybeJustJames]

The correct gauge metabolite can be ambiguous when parsing the metabolites line (when there are multiple metabolites at the end of the list).

e.g.

...,{'CARBON-DIOXIDE':('2(1)__',(('2__',1),),'F'),'UMP':('0(1)_1(1)___________________',(('0_1___________________',1),),'T')}]

It's only from the filename that I happen to know that the correct one is UMP. Is there any other way? Because the server does not see a filename, it only sees the data.

[MaybeJustJames]

'T' in the LAST step is the GAUGE