Reactivities of Radiation-protective Aminoalkylisothiuronium Salts. II. Spectrophotometric Studies on the Reductivities of 2-Mercaptoethylamine, 2-Mercaptoethyl-, and 3-Mercaptopropyl-guanidine.

抄録

The conjugate bases of AET and APT are transguanylated rapidly and nearly quantitatively to MEG and MPG respectively, which are determined spectrophotometrically with ferric 1, 10-phenanthrolinate. The ferric complex enhanced the transguanylation of AET, but not APT. This finding suggests the possibility that AET would be easily transguanylated by metal ions or metal complexes which is contained in the body fluid, even though AET itself is injected. Aminothiols, such as MEA, MEG and MPG, displayed two maxima of the reduction abilities ; one appeared at pH 3.2 and another at pH 5.0, and a minimum at pH 4.0. At those two pH regions, the reaction pathways and the products might be different. As the acidic region, the reductivities were parallell with the acidities of the aminothiols.