Gaitonde M K
Biochem J. 1974 Jun;139(3):625-31. doi: 10.1042/bj1390625.
Tryptophan, tryptamine and peptides containing N-terminal tryptophan give two highly fluorescent products on treatment with dithiothreitol and acid ninhydrin reagent 1 or 2. The first fluorescent product (product A) gives an emission at 500nm on activation at 390-400nm and is stable for 20min. The second product (product B), which gives an emission at 530nm on activation at 470nm, is detectable within 1h after the reaction. It gives almost maximum intensity in 4h and is stable for at least 48h. Except lysine, which in equimolar amounts gives less than 1% of a product similar to product B, no other naturally occurring amino compounds give fluorescent products. A procedure is given for the determination of 0.05-34nmol of tryptophan in tissue extracts. By using this procedure rat brain was found to contain 17.56+/-0.76 (s.e.m.) nmol/g wet wt.
色氨酸、色胺以及含N端色氨酸的肽在用二硫苏糖醇和酸性茚三酮试剂1或2处理时会产生两种高度荧光的产物。第一种荧光产物（产物A）在390 - 400nm激发时在500nm处发射荧光，并且在20分钟内稳定。第二种产物（产物B）在470nm激发时在530nm处发射荧光，在反应后1小时内可检测到。它在4小时内达到几乎最大强度，并且至少48小时稳定。除了赖氨酸（等摩尔量时产生的类似于产物B的产物不到1%）外，没有其他天然存在的氨基化合物会产生荧光产物。给出了一种测定组织提取物中0.05 - 34nmol色氨酸的方法。通过使用该方法，发现大鼠脑含有17.56±0.76（标准误）nmol/g湿重。
