一系列环戊二醚衍生物对低氧和富氧 EMT6 肿瘤细胞的杀伤能力进行了测试，包括米托霉素-C（MC）和卟吩霉素（POR）。在 MC 和 POR 的 C-7 处进行氨甲基环戊二醚和硫醚环戊二醚取代，可明显提高化合物对低氧 EMT6 肿瘤细胞的细胞毒性，但对富氧毒性的影响不大。相反地，N1a 处的甲基取代显著降低了化合物的富氧细胞毒性，但未改变低氧细胞毒性。POR 环戊二醚 BMY-42355 在 MC 类似物中观察到低氧和富氧细胞毒性之间的最大差异。小鼠的初步研究表明，BMY-42355 单独或与放射线联用对抗癌活性良好，毒性低于 POR；该化合物在这些初步研究中的治疗比为 MC 或 POR 的任何一个都更高。

A series of cyclic acetal derivatives of mitomycin C (MC) and porfiromycin (POR) were tested for their ability to kill hypoxic and oxygenated EMT6 tumor cells. Amino methyl acetal and thioacetal substitutions at C-7 of MC and POR dramatically increased the cytotoxicity of the compounds to hypoxic EMT6 tumor cells in vitro but had little effect on the aerobic toxicities. In contrast, a methyl substitution at N1a markedly decreased the aerobic cytotoxicities of the compounds but did not alter the hypoxic cytotoxicities. The POR acetal, BMY-42355, had the largest differential between hypoxic and aerobic cytotoxicities yet observed among MC analogs. Preliminary studies in mice showed that BMY-42355 had good antineoplastic activity when used alone or in combination with radiation and was less toxic than POR; the therapeutic ratio of this compound in these initial studies was higher than those of either MC or POR.