The new endoperoxyketal polyketides manadoperoxides A-D (2-5) have been isolated from he Indonesian sponge Plakortis cfr. simplex and their stereostructures established by means of spectroscopic data and semisynthetic transformations. Manadoperoxides were assayed in vitro against D10 and W2 strains of Plasmodium falciparum and showed moderate antimalarial activity compared to that of plakortin (1) and peroxyplakoric B-3 ester (9), the latter differing from manadoperoxide 13 only by minor structural details. This unexpected difference in the antimalarial activity has been rationalized on the basis of our recently published model for the interaction of 1,2-dioximes with heme and production of C-centered radicals toxic to the parasite. For the manadoperoxides, either the endoperoxide linkage is inaccessible to the heme iron or the O1 radical cannot evolve to produce a C-centered radical.
Manadoperoxides A-D from the Indonesian Sponge Plakortis cfr. simplex. Further Insights on the Structure-Activity Relationships of Simple 1,2-Dioxane Antimalarials / Fattorusso, C.; Persico, M.; Calcinai, Barbara; Cerrano, Carlo; Parapini, S.; Taramelli, D.; Novellino, E.; Romano, A.; Scala, F.; Fattorusso, E.; Taglialatela Scafat, O.. - In: JOURNAL OF NATURAL PRODUCTS. - ISSN 0163-3864. - 73:(2010), pp. 1138-1145. [10.1021/np100196b]
Manadoperoxides A-D from the Indonesian Sponge Plakortis cfr. simplex. Further Insights on the Structure-Activity Relationships of Simple 1,2-Dioxane Antimalarials
CALCINAI, Barbara;CERRANO, CARLO;
2010-01-01
Abstract
The new endoperoxyketal polyketides manadoperoxides A-D (2-5) have been isolated from he Indonesian sponge Plakortis cfr. simplex and their stereostructures established by means of spectroscopic data and semisynthetic transformations. Manadoperoxides were assayed in vitro against D10 and W2 strains of Plasmodium falciparum and showed moderate antimalarial activity compared to that of plakortin (1) and peroxyplakoric B-3 ester (9), the latter differing from manadoperoxide 13 only by minor structural details. This unexpected difference in the antimalarial activity has been rationalized on the basis of our recently published model for the interaction of 1,2-dioximes with heme and production of C-centered radicals toxic to the parasite. For the manadoperoxides, either the endoperoxide linkage is inaccessible to the heme iron or the O1 radical cannot evolve to produce a C-centered radical.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.