In a series of 26 species selected from widely differing classes, 1,2-dichloro-4,5-diaminobenzene was toxic to those which did not exhibit a nutritional need for riboflavin plus vitamin B12. It failed to retard the growth of those which needed both of these vitamins. The compound was conceived as an antimetabolite of 1,2-dimethyl-4,5-diaminobenzene. This latter, which is contained within the structures of the two vitamins, was pictured as a metabolic precursor of them. It was found to have very slight activity as either riboflavin or as vitamin B12 for lactic acid bacteria and algae. The growth-inhibiting action of the dichlorodiaminobenzene was overcome competitively by the dimethyidiaminobenzene, and also, to a lesser extent, by o-phenylenediamine. The toxicity was not influenced by additions of riboflavin plus vitamin B12, except in the cases of two species, where the influence was slight. These facts were considered to support the idea that properly constructed analogs of a precursor of two or more essential participants in cell division may be able to circumvent the counteraction which the vitamin has been found to exert on an antimetabolite of its precursor. Alternate explanations of the observed data were likewise considered.
在从不同类群中选择的26种物种中,1,2-二氯-4,5-二氨基苯对那些不表现出核黄素和维生素B12营养需求的物种具有毒性。它未能抑制那些需要这两种维生素的生长。该化合物被认为是1,2-二甲基-4,5-二氨基苯的抗代谢物。这后者被描绘为它们的代谢前体,含在这两种维生素的结构中。发现它对乳酸菌和藻类的核黄素或维生素B12的活性非常微弱。二氯二氨基苯的生长抑制作用被二甲基二氨基苯和少量的邻苯二胺竞争性地克服。除了两种物种的影响轻微外,核黄素加维生素B12的添加并未影响其毒性。这些事实被认为支持这样一个想法,即适当构建的两个或多个细胞分裂中必需参与者的前体的类似物可能能够规避维生素对其前体的抗代谢物所产生的对抗作用。同时,也考虑了观察到的数据的其他解释。