Total Synthesis and Antimalarial Activity of 2-(-Hydroxybenzyl)-Prodigiosins, Isoheptylprodigiosin, and Geometric Isomers of Tambjamine MYP1 Isolated from Marine Bacteria.
Highly efficient and straightforward synthetic routes toward the first total synthesis of 2-(-hydroxybenzyl)-prodigiosins (-), isoheptylprodigiosin (), and geometric isomers of tambjamine MYP1 ((/)-) have been developed. The crucial steps involved in these synthetic routes are the construction of methoxy-bipyrrole-carboxaldehydes (MBCs) and a 20-membered macrocyclic core and a regioselective demethylation of MBC analogues. These new synthetic routes enabled us to generate several natural prodiginines - in larger quantity. All of the synthesized natural products exhibited potent asexual blood-stage antiplasmodial activity at low nanomolar concentrations against a panel of parasites, with a great therapeutic index. Notably, prodiginines and - provided curative in vivo efficacy against erythrocytic at 25 mg/kg × 4 days via oral route in a murine model. No overt clinical toxicity or behavioral change was observed in any mice treated with prodiginines and tambjamines
