Toxicity of Singlet Oxygen Generated Thermolytically in Escherichia coli.
作者:Tetsuo NAGANO、Takako TANAKA、Hitomo MIZUKI、Masaaki HIROBE
DOI:10.1248/cpb.42.883
日期:——
Three water-soluble derivatives of naphthalene endoperoxide were prepared to examine the toxicity of singlet oxygen towards Escherichia coli. On incubation without irradiation, these endoperoxides produce singlet oxygen thermolytically in a dose-dependent manner. The amount of singlet oxygen produced per unit time can be controlled by varying both the incubation temperature and the number of methyl substituents of the naphthalene endoperoxide derivatives. 3-(1, 4-Dihydro-1, 4-epidioxy-4-methyl-1-naphthyl)propionic acid(EP-1), one of the derivatives, inhibited E. coli growth dose- and incubation temperature-dependently and caused E. coli lethality. Furthermore, EP-1 did not induce superoxide dismutase or catalase in E. coli even when the cells were incubated in nutritionally rich medium containing trypticase/soy/yeast extract. Singlet oxygen, one of the reactive oxygen species, did not act as a signal for induction of superoxide dismutase and catalase, in contrast to the actions of superoxide and hydrogen peroxide.
为了研究单线态氧对大肠杆菌的毒性,我们制备了萘内过氧化物的三种水溶性衍生物。在不经辐照的培养条件下,这些内过氧化物以剂量依赖的方式热解产生单线态氧。单位时间内产生的单线态氧的数量可以通过改变孵育温度和萘内过氧化物衍生物的甲基取代基数量来控制。其中一种衍生物 3-(1, 4-二氢-1, 4-环氧-4-甲基-1-萘基)丙酸(EP-1)对大肠杆菌生长的抑制作用与剂量和培养温度有关,并导致大肠杆菌死亡。此外,即使将大肠杆菌培养在含有胰蛋白酶/大豆/酵母提取物的营养丰富的培养基中,EP-1 也不会诱导大肠杆菌体内的超氧化物歧化酶或过氧化氢酶。单线态氧是活性氧之一,与超氧化物和过氧化氢的作用相反,单线态氧并不作为诱导超氧化物歧化酶和过氧化氢酶的信号。