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