光照（＞４７０ｎｍ）竹红菌乙素和Ｎａ＿２ＳＯ＿３的溶液可生成５或８位磺化和５，８－二位磺化的竹红菌乙素衍生物。竹红菌乙素的光磺化反应对反应条件（如氧的浓度、溶液的ｐＨ值、溶剂的极性）的变化非常敏感。在空气条件下，磺化速度比在无氧条件下大大加快，同时也防止了氧条件下的一些副反应如自敏光氧化等的发生。这一磺化反应发生的最佳ｐＨ值为７．０～７．７。磺化速度随溶剂极性的降低而迅速下降，强极性有机溶剂与缓冲液组成的混合溶剂（１：１／Ｖ：Ｖ）有利于该反应的发生。 Illumination (> 470 nm) The solution of hypocrellin B and Na 2 SO 3 can produce the hypocrellin B derivative with 5 or 8 sulfonation and 5,8-disulfonation. The photodegradation of hypocrellins B is very sensitive to changes in reaction conditions (eg oxygen concentration, pH of the solution, polarity of the solvent). Under air conditions, the sulfonation rate is much faster than under anaerobic conditions, but also prevent the occurrence of some side reactions such as self-sensitive photooxidation under oxygen conditions. The optimum pH for this sulfonation reaction is 7.0-7.7. The sulfonation rate decreased rapidly with the decrease of solvent polarity. The mixed solvent (1: 1 / V: V) of strong polar organic solvent and buffer was favorable to the reaction.