preferred_name: pteridine-2,4,6,7-tetrol <=> xanthine-8-carboxylate + H(+)
preferred_name_lc: pteridine-2,4,6,7-tetrol <=> xanthine-8-carboxylate + h(+)
label: pteridine-2,4,6,7-tetrol <=> xanthine-8-carboxylate + H(+)
label_lc: pteridine-2,4,6,7-tetrol <=> xanthine-8-carboxylate + h(+)