Improved synthetic methods of firefly luciferin derivatives, such as 6-O-alkanoylluciferins and 6-O-phosphonoluciferin, are described. These derivatives proved to be useful as substrates for the bioluminescent assay of hydrolytic enzymes such as carboxylic esterase and alkaline phosphatase. The synthetic methods previously reported gave fairly low yields because of direct derivatization of unstable luciferin itself and are difficult to be applied to large-scale synthesis because of unavoidable HPLC purification. We first modified the hydroxyl group of 2-cyano-6-hydroxybenzothiazole and then condensed the resulting stable products with d-cysteine to give the appropriate derivatives in good yields without HPLC purification. 6-O-Phosphonoluciferin was unstable as free acid form but stable as its sodium salt.
                                    描述了萤火虫
荧光素衍
生物(例如 6-O-烷酰
荧光素和 6-O-膦酰
荧光素)的改进合成方法。这些衍
生物被证明可用作
水解酶(例如
羧酸酯酶和碱性
磷酸酶)的
生物发光测定的底物。先前报道的合成方法由于不稳定的
荧光素本身直接衍生化而产率相当低,并且由于不可避免的HPLC纯化而难以应用于大规模合成。我们首先修饰 
2-氰基-6-羟基苯并噻唑的羟基,然后将所得稳定产物与 d-半胱
氨酸缩合,无需 HPLC 纯化即可以良好的收率得到合适的衍
生物。 6-O-
磷酸荧光素以
游离酸形式不稳定,但以钠盐形式稳定。