[Synthesis of zinc chlorophyllin a and its preliminary clinical application]

A method for synthesis of zinc chlorophyllin a (I), a promising drug for clinical application, is presented. Taking silkworm faeces as a raw material. Chlorophyll was extracted with ethyl alcohol. After concentration the solid formed was dissolved in petroleum ether and the solution was subjected to column chromatography to separate pheophytin a and chlorophyll a. The products were dissolved in ethyl ether and the Mg in the products was stripped off with concentrated hydrochloric acid. The excess hydrochloric acid in the solution was neutralized with ammonia solution and the mixture was hydrolyzed with diluted hydrochloric acid to obtain pheophorbide a, then (I) was synthesized with pheophorbide a and zinc salt. The characteristics of (I) and pheophorbide a were checked by IR, UV and elemental analyses. All results of pheophorbide a coincided with those values reported in literature. The acute toxicity of (I) was tested in mice and the LD50 of (I) was 324 +/- 40 mg/kg. (I) has been applied in several hospitals for several months. It has been found that (I) has outstanding effects on burns and oral sepsis and that it increases the growth of granulation tissue and epithelium remarkably.