Non-iron porphyrins inhibit beta-haematin (malaria pigment) polymerisation.
Infrared spectroscopy was used to evaluate the effect of non-iron porphyrins (protoporphyrin IX and haematoporphyrin) on haematin polymerisation to beta-haematin at acidic pH. Both molecules effectively inhibited the reaction, with haematoporphyrin 6 times as active as protoporphyrin IX. We postulated that the interaction between the pi electron system of porphyrin rings leads to the formation of pi-pi adducts, which inhibit polymer elongation in the same way as antimalarial drugs (e.g., chloroquine); the presence of hydroxyl groups able to bind haem iron enhances activity.
Basilico
N
N
Instituto di Microbiologia Medica, Università di Milano, Milan, Italy.
Monti
D
D
Olliaro
P
P
Taramelli
D
D
D000962:Antimalarials / Q000378:metabolism; D002738:Chloroquine / Q000037:antagonists & inhibitors* / Q000378:metabolism; D019281:Dimerization; D006415:Hematoporphyrins / Q000494:pharmacology*; D006420:Hemeproteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006427:Hemin / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006801:Humans; D016778:Malaria, Falciparum / Q000378:metabolism; D011108:Polymers / Q000378:metabolism*; D011524:Protoporphyrins / Q000494:pharmacology*; D017550:Spectroscopy, Fourier Transform Infrared
D000962:Antimalarials; D006415:Hematoporphyrins; D006420:Hemeproteins; D011108:Polymers; D011524:Protoporphyrins; C069269:ferriprotoporphyrin IX-chloroquine complex; C020753:hemozoin; D006427:Hemin; D002738:Chloroquine; C028025:protoporphyrin IX