Peroxidase catalyzed formation of azine pigments—a convenient and sensitive method for the identification of human cells with positive myeloperoxidase reactivity

A new and efficient method for the identification of human cells with positive myeloperoxidase reactivity was developed. This method is based on the myeloperoxidase catalyzed formation of p-naphthoquinone-thiazol-2-on-azine pigments and offers a number of advantages compared to standard methods. In addition, we report the horseradish peroxidase (HRP) catalyzed oxidative coupling of 2-hydrazono-4-thiazolines with α-naphthol. This transformation allows a new and efficient synthesis of p-naphthoquinone-thiazol-2-on-azines under mild conditions.