Metabolism of polycyclic compounds. 22. The metabolism of trans-9,10-dihydro-9,10-dihydroxyphenanthrene in rats.

Dihydrodihydroxy compounds are important intermediates in the metabolic pathways of aromatic hydrocarbons, giving rise to many of the metabolites observed in the urine when the parent hydrocarbons are given to animals. Thus, for example, when tran8-1,2-dihydro-1,2-dihydroxynaphthalene is given to rats it is excreted partly unchanged in conjugation with glucuronic acid, partly as 1-naphthol in conjugation with sulphuric acid and glucuronic acid, partly as 2-naphthol and partly as 1,2-dihydroxynaphthalene in conjugation with sulphuric acid (Corner & Young, 1955; Sims, 1959), all of which are also products of naphthalene metabolism. Boyland & Wolf (1950) showed that phenanthrene is converted into trans-9,10-dihydro9,10-dihydroxyphenanthrene by rats and rabbits and into tran8-1,2-dihydro-1,2-dihydroxyphenanthrene by rabbits. The present work has shown that trans-9, 10-dihydro-9,10-dihydroxyphenanthrene is converted by rats into conjugates of the dihydrodihydroxy compound with sulphuric acid and glucuronic acid and into the sulphuric acid conjugate of 9,10-dihydroxyphenanthrene. Conjugates of 9hydroxyphenanthrene were not detected, although a small amount of the free phenol was present.