obsolete 2,3-dihydroxy-2'-carboxybiphenyl 1,2-dioxygenase activity (obsolete GO:0034788)
OBSOLETE. Catalysis of the reaction: 2,3-dihydroxy-2'-carboxybiphenyl + O2 = 2-hydroxy-6-oxo-6-(2-carboxyphenyl)-hexa-2,4-dienoate + H+.