THE ISOMERIC TRANSFORMATION OF UREA INTO AMMONIUM CYANATE IN AQUEOUS SOLUTIONS
THE ISOMERIC TRANSFORMATION OF UREA INTO AMMONIUM CYANATE IN AQUEOUS SOLUTIONS
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DOI：
10.1042/bj0420628
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发表时间：
1948-01-01
影响因子：
4.1
通讯作者：
SCHUTZ, F
中科院分区：
文献类型：
--
作者：
DIRNHUBER, P;SCHUTZ, F
步行者和汉布利（1895）指出氰酸铵向尿素的异构转化（沃勒，1828）在水溶液中是自发可逆的。在1000 ℃下平衡时，0- 1 M尿素溶液据说含有约95%尿素和5%氰酸铵。维尔纳（1923）否认尿素在60 ℃以下形成氰酸盐。根据这位作者的说法，在室温或体温下在无菌条件下保存数月的尿素水溶液不含痕量的氰酸盐。由于最近描述了氰酸盐的一些药理作用（Schutz，1945，1946; Birch & Schutz，1946），因此研究了哺乳动物器官中是否形成氰酸盐的问题。作为研究这个问题的第一步，进行了实验，唯一的目的是确定氰酸盐是否在尿素水溶液中在体温或室温下自发形成。涉及活组织的实验将另行报告。从理论上讲，所讨论的同分异构体变化可以通过显示溶液中最初存在的尿素量的逐渐减少来证明。然而，由于即使在高温下，只有一小部分原来存在的尿素已知经历异构体转化为NH 4CNO，预期的减少可能在最灵敏的尿素定量方法的误差范围内。另一方面，发现现有的用于检测和定量测定氰酸盐的方法（步行者& Hambly，1895; Hertig，1901）太不灵敏，尤其是当尿素以较高浓度存在时。本文介绍了两种定性定量测定水溶液中氰酸盐的新方法。通过这些程序的证据，获得了自发形成氰酸盐在尿素水溶液中，在身体和室温。
Walker & Hambly (1895) showed that the isomeric transformation of ammonium cyanate into urea (Wohler, 1828) was spontaneously reversible in aqueous solutions. At equilibrium at 1000, a 0-lM-solution of urea was said to contain approximately 95% urea and 5% ammonium cyanate. Werner (1923) denied formation of cyanate from urea at temperatures below 60. According to this author aqueous solutions of urea, kept for many months at room or body temperature under sterile conditions, did not contain traces of cyanate. Since some pharmacological actions of cyanate were recently described (Schutz, 1945, 1946; Birch & Schutz, 1946), the question whether cyaneFte is formed in the mammalian organim was investigated. As the first step in studying this question, experiments were carried out with the sole aim of establishing whether cyanate was spontaneously formed in aqueous solutions of urea, at body or room temperature. Experiments dealing with living tissues will be reported separately. The isomeric change in question could, theoreti-cally, be demonstrated by showing a gradual decrease in the amount of ureaoriginally presentin-the solution. Since, however, even at high temperatures, only a small percentage oftheurea originally present is known to undergo the isomeric change into NH4CNO, the expected decreasewould probably be within the margin oferror of the most sensitive quantitative methodsfor the determination of urea. On the other hand, the existing methods for the detection and quantitative determination ofcyanate (Walker & Hambly, 1895; Hertig, 1901) were found to be too insensitive, especially when urea was present in higher concentrations. In this paper two new methods are described for the qualitative and quantitative determinationof cyanate in aqueous solutions. By means of these procedures evidence was obtained for the spontaneous formation of cyanate in aqueous solutions of urea, at body and room temperature.