New Cyclic Lipopeptides of the Iturin Class Produced by Saltern-DerivedBacillus sp. KCB14S006
Sangkeun Son, Sung-Kyun Ko, Mina Jang, Jong Won Kim, Gil Soo Kim, Jae Kyoung Lee, Eun Soo Jeon, Yushi Futamura, In-Ja Ryoo, Jung-Sook Lee, Hyuncheol Oh, Young-Soo Hong, Bo Yeon Kim, Shunji Takahashi, Hiroyuki Osada, Jae-Hyuk Jang, Jong Seog Ahn
Salterns, one of the most extreme natural hypersaline environments, are a rich source of halophilic and halotolerant microorganisms, but they remain largely underexplored ecological niches in the discovery of bioactive secondary metabolites. In continued efforts to investigate the metabolic potential of microbial populations from chemically underexplored sites, three new lipopeptides named iturin F1, iturin F2 and iturin A9 (1–3), along with iturin A8 (4), were isolated from Bacillus sp. KCB14S006 derived from a saltern. The structures of the isolated compounds were established by 1D-, 2D-NMR and HR-ESIMS, and their absolute configurations were determined by applying advanced Marfey’s method and CD spectroscopy. All isolates exhibited significant antifungal activities against various pathogenic fungi and moderate cytotoxic activities toward HeLa and srcts-NRK cell lines. Moreover, in an in vitro enzymatic assay, compound 4 showed a significant inhibitory activity against indoleamine 2,3-dioxygenase.
Circular dichroism, Absolute configuration, Pharmaceutical, Medicinal