Popis: |
Under mild alkaline conditions hemin can be catalytically hydrogenated to the iron complex of mesoporphyrin IX. Subsequent demetallation yields mesoporphyrin IX. In this way pure mesoporphyrin IX becomes readily accessible. In contrast, the mesoporphyrin produced from hemin by formic acid reduction has been shown by partition chromatography to be a mixture rather than a pure compound. Mesoporphyrin IX can be converted to pure etioporphyrin III in 20% yield by a seven-step reaction series including the Curtius rearrangement, Hofmann degradation, and catalytic hydrogenation. |