Antitrypanosomal peptaibiotics, trichosporins B-VIIa and B-VIIb, produced by Trichoderma polysporum FKI-4452

摘要

In the course of screening for new antitrypanosomal agents, several novel bioactive natural compounds have been discovered and reported by our group. Recently, we have isolated two new trichosporin analogs, designated as trichosporins B-VIIa (1) and B-VIIb (2), together with five known trichosporins (3-7), from the culture broth of Trichoderma sp. FKI-4452. These have proved to exhibit antitrypanosomal activity (Figure 1). In this paper, the fermentation, isolation, structure elucidation and biological activity of these novel trichosporins are described. Fungal strain FKI-4452 was isolated from a soil sample collected in Yakushima-Island, Kagoshima, Japan by the dilution plating method. The ITS sequence of strain FKI-4452 was determined and deposited at the DNA Data Bank of Japan, with the accession number AB517619, using The TrichOKEY program of ITSH (International Subcommis-sion on Trichoderma and Hypocrea Taxonomy), which suggested that the strain FKI-4452 belongs to Trichoderma polysporum. Moreover, FKI-4452 was a 98% match to the nucleotide sequences of T. polysporum CBS 820.68 according to the TrichoBLAST database of ITSH.5 Thus, the strain FKI-4452 was identified as T. polysporum and designated Trichoderma polysporum FKI-4452. There was no report of trichosporin production by T. polysporum CBS 820.68.