Chromogenic enzyme substrate compounds comprising a dibenz[b,e] [1,4]oxazepinone or dibenzo[b,e][1,4]thiazepinone nucleus having an enzyme-cleavable group such as a radical of a sugar, carboxylic acid, amino acid, peptide, phosphoric acid, or sulfuric acid. The substrate compounds are, in general, highly soluble in aqueous media and only slightly colored, and produce, upon enzyme cleavage, a chromogen exhibiting a large change in absorbance and a pKa below 7. Such substrates find use as indicators for the determination of enzyme analytes and enzymes used as markers in a variety of assays, including immunoassays.
致色酶底物化合物包括二苯并[b,e][1,4]氧氮杂卓酮或二苯并[b,e][1,4]
硫氮杂卓酮核,其核具有酶可切除的基团,如糖、
羧酸、
氨基酸、肽、
磷酸或
硫酸的基团。底物化合物一般在
水介质中的溶解度很高,只有轻微的颜色,在酶裂解后会产生一种吸光度变化很大、pKa 低于 7 的
显色剂。这类底物可用作测定酶分析物的指示剂,也可用作各种检测(包括免疫检测)中的酶标记物。