| | Iron Protoporphyrin IX (heme) | Zinc Protoporphyrin IX (ZnPP) | Zinc Protoporphyrin IX 2,4 Bisglycol (ZnBG) | Tin Protoporphyrin IX (SnPP) |
|---|
X | Fe | Zn | Zn | Sn |
Y | -CH=CH2 | -CH=CH2 | -CHOHCH2OH | -CH=CH2 |
Me | -CH3 | -CH3 | -CH3 | -CH3 |
P | -CH2-CH2-COOH | -CH2-CH2-COOH | -CH2-CH2-COOH | -CH2-CH2-COOH |
- Hemozoin is formed upon the chemical crosslinking of the central iron of one heme with a carboxy group of another heme. All heme polymerization inhibitors contained the carboxy group as part of the propionate side chain (P). The central metal (X) varies according to the inhibitor, probably serving as chain terminators. The vinyl groups (Y) remain the same, except in ZnBG, in which they were substituted for glycols, enhancing compound solubility. Methyl groups (Me) remain unchanged throughout.
