OPTIMIZATION OF CONDITION FOR METHYL PHEOPHORBIDE A FORMATION AND CONVERSION TO CHLORIN E6

Chlorin e6 is a stable chlorophyll derivative and can be used in photodynamic therapy (PDT) to treat cancer. One of the synthetic pathways of chlorin e6 is via the transformation of chlorophyll a to methyl pheophorbide a. In this study, we optimize the experimental condition for obtaining methyl pheophorbide a from chlorophyll extracted from Spirulina. The preliminary study showed that the suitable solvent system for extracting chlorophyll from the extract was dichloromethane and n-hexane in a ratio of 1:1. To determine the optimal parameters of 4 factors: time, temperature, chlorophyll/H2SO4 ratio (w/v), chlorophyll/MeOH ratio (w/v) to obtain the highest conversion efficiency of methyl pheophorbide a. The experimental matrix followed the Box- Behnken design to investigate the optimal region, with experiments for four factors at three levels to build the indicator surface. The optimal conditions for preparing methyl pheophorbide a from chlorophyll: Chlorophyll/H2SO4 ratio was 4/5 (w/v), chlorophyll/CH3OH ratio was 6/50 (w/v), time was 4.4 hours and temperature was 44oC. Chlorin e6 was successfully prepared from methyl pheophorbide a. Keywords: Spirulina; Chlorin; photodynamic therapy