Dibenzanthracene 1:2:5:6 as a Carcinogenic Agent

Abstract

<b>Introduction</b> In 1931, an editorial in the London <i>Lancet</i> (1) furnished the following admirably brief and succinct summary of the early phase of the work done with dibenzanthracene: “In February, 1929, a method for the synthesis of 1:2:5:6 dibenzanthracene was published in a German chemical journal, having no connexion with cancer research [Clar, 2]. This is only one of a great number of new compounds constantly being produced by organic chemists, and there would have been nothing to draw attention to its possibilities as a carcinogenetic agent, had not Mr. I. Hieger, working at the Cancer Hospital under the general direction of Prof. E. L. Kennaway, been on the lookout for new compounds closely related to benzanthracene. For he had previously noticed the resemblance between the fluorescence spectrum of benzanthracene and that of a cancer-producing coal tar, and the association had led him to seek a pure chemical substance which would replace coal tar as a carcinogenetic agent. Benzanthracene itself, which consists of four benzene rings fused together, has only feeble cancer-producing power; in a series of 70 mice painted with it, only one papilloma appeared. But the addition of one more benzene ring in a certain position (dibenzanthracene) has given 58 cancers and 9 papillomas in 190 mice, of which 104 lived more than six months…. The two compounds which, up to the present, have been found most active differ from the almost inactive parent substance, benzanthracene, in that the molecule, as shown in the conventional graphic formula, is extended at the lower left-hand corner, in one case by the <i>iso</i>propyl group CH—in the other by a fifth benzene ring. The question whether this type of molecular structure has any general significance in cancer production must be decided by much further work….