Koshidacins A and B, Antiplasmodial Cyclic Tetrapeptides from the Okinawan Fungus <i>Pochonia boninensis</i> FKR-0564
Yoshihiro Watanabe, Kodai Hachiya, Akari Ikeda, Kenichi Nonaka, Mayuka Higo, Reiko Muramatsu, Chikako Noguchi, Masako Honsho, Yukihiro Asami, Yuki Inahashi, Tomoyasu Hirose, Hidehito Matsui, Toshiaki Sunazuka, Hideaki Hanaki, Takahiro Ishii, Toshiaki Teruya, Rei Hokari, Aki Ishiyama, Masato Iwatsuki
Abstract
Two new antiplasmodial peptides, named koshidacins 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 derivatization. Both compounds showed moderate in vitro antiplasmodial activity against Plasmodium falciparum strains, with IC50 values ranging from 17.1 to 0.83 μM. 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.