Koshidacins A and B, Antiplasmodial Cyclic Tetrapeptides from the Okinawan Fungus Pochonia boninensis FKR-0564

Two new antiplasmodial peptides, named koshida-cins A (1) and B (2), were discovered from the culture broth of the Okinawan fungus Pochonia boninensis FKR-0564. Their structures, including absolute configurations, were elucidated by a combination of spectroscopic methods and chemical derivatiza-tion. Both compounds showed moderate in vitro antiplasmodial activity against Plasmodium falciparum strains, with IC50 values ranging from 17.1 to 0.83 mu M. In addition, compound 2 suppressed 41% of malaria parasites in vivo when administered intraperitoneally at a dose of 30 mg/kg/day for 4 days.

Automated summary

Two new antiplasmodial peptides, named koshida-cins A and B, were discovered from the culture broth of the Okinawan fungus Pochonia boninensis FKR-0564. Both compounds showed moderate in vitro antiplasmodial activity against Plasmodium falciparum strains, and compound 2 demonstrated significant suppression of malaria parasites in vivo.