Yao K, Ubuka T
Department of Biochemistry, Okayama University Medical School, Japan.
Acta Med Okayama. 1987 Dec;41(6):237-41. doi: 10.18926/AMO/31741.
A new acidic ninhydrin method for determining free sialic acids is described. The method is based on the reaction of sialic acids with Gaitonde's acid ninhydrin reagent 2 which yields a stable color with an absorption maximum at 470 nm. The standard curve is linear in the range of 5 to 500 nmol of N-acetylneuraminic acid per 0.9 ml of reaction mixture. The reaction was specific only for sialic acids among the various sugars and sugar derivatives examined. Some interference of this method by cysteine, cystine and tryptophan was noted, although their absorption maxima differed from that of sialic acids. The interference by these amino acids was eliminated with the use of a small column of cation-exchange resin. The acidic ninhydrin method provides a simple and rapid method for the determination of free sialic acids in biological materials.
本文描述了一种用于测定游离唾液酸的新型酸性茚三酮法。该方法基于唾液酸与盖通德酸性茚三酮试剂2的反应，该反应产生一种稳定的颜色，其最大吸收波长为470nm。标准曲线在每0.9ml反应混合物中5至500nmol N-乙酰神经氨酸的范围内呈线性。在所检测的各种糖和糖衍生物中，该反应仅对唾液酸具有特异性。虽然半胱氨酸、胱氨酸和色氨酸的最大吸收波长与唾液酸不同，但注意到它们对该方法有一定干扰。使用一小柱阳离子交换树脂可消除这些氨基酸的干扰。酸性茚三酮法为测定生物材料中的游离唾液酸提供了一种简单快速的方法。
