STUDIES OF PHENANTHRENE DERIVATIVES I. A COMPARISON OF PHENANTHRENE AND SOME 2-, 3-, AND 9-MONOSUBSTITUTION PRODUCTS

¹ From the Laboratory of Pharmacology, University of Michigan Medical School, Ann Arbor, Michigan

Phenanthrene and four series of derivatives have been administered orally to cats. Each series comprises three members in which a single chemical group has been attached to the phenanthrene nucleus in the 2-, 3- or 9-position. The groups are acetyl, carboxylic acid, hydroxyl, and amino.

Absorption of these substances appeared to begin promptly in spite of their almost complete insolubility in water for effects could be detected an hour after administration. Absorption probably proceeds slowly, however, for peak effects were observed, as a rule, two to five hours after a substance was given. Recovery also was slow, requiring twelve to twenty-four hours or longer in some cases.

Phenanthrene produced mild general depression, the picture presented being very like that following the administration of a small dose of one of the barbiturates. All of the derivatives had a greater depressant effect than had phenanthrene. In each series the most active member was the one in which the substitution had been made in the 3-position.

Among the 3-derivatives the approximate order of depressant activity is 3-aminophenanthrene, phenanthrene-3-carboxylic acid, 3-hydroxyphenanthrene, and 3-acetylphenanthrene. The first named is the most depressant.

3-Aminophenanthrene, phenanthrene-3-carboxylic acid and 3-hydroxyphenanthrene were definitely analgesic. 2-Aminophenanthrene, when given in approximately fatal dose, was also analgesic, but phenanthrene and the other derivatives were not analgesic in the doses used.

Phenanthrene-9-carboxylic acid produced a peculiar type of muscular disturbance, characterized chiefly by an exaggerated extensor response in the hind legs and by a delayed relaxation of all of the muscles. This is being studied further.