The key points for extraction of natural edible purpurin and blue pigment are described.

本文详述了天然食用紫色素和蓝色素的提取技术和操作要点。

In basic condition E ring was converted into the cyclohexanedicarboxylic anhydride to form purpurin 18 derivatives by the air oxidation.

在碱性条件下，通过空气氧化将E环转变为环己二羧酸酐形成红紫素18甲酯衍生物；

A series of novel purpurin-18 imide derivatives with long absorption wavelength were synthesized through Wittig reaction of methyl pheophorbide-a.

合成的一系列红紫素-18酰亚胺衍生物具有长波长的紫外吸收。