intratransguanylation is dependent on pH as well as on the number of carbon atoms between the amino and isothiourea groups. The aminoethyl- and aminopropylisothioureas intratransguanylate readily at neutral pH but 5,4- aminobutylisothiourea does not. At pH's 3--6, 2-aminothiazolines and - penthiazolines are formed, whereas in strong ailali, mixtures of mercaptoguanidines and mercaptoamines are formed. NAlkyl substitution
使用定量离子交换色谱法确定
鸟苷内转移取决于 pH 值以及
氨基和异
硫脲基团之间的碳原子数。
氨基乙基和
氨基丙基异
硫脲在中性 pH 值下很容易转
鸟苷酸,但 5,4-
氨基丁基异
硫脲则不然。在 pH 值为 3--6 时,会形成
2-氨基噻唑啉和 - 戊
噻唑啉,而在强碱中,会形成巯基
胍和巯基胺的混合物。各种 N 原子上的 Nalkyl 取代改变了发生内环
鸟苷化的 pH 值以及所得产物的形成和组成的速率。(授权)