Iminimycin A, the new iminium metabolite produced by Streptomyces griseus OS-3601
Takuji Nakashima, Rei Miyano, Masato Iwatsuki, Tatsuya Shirahata, Toru Kimura, Yukihiro Asami, Yoshinori Kobayashi, Kazuro Shiomi, George A Petersson, Yōko Takahashi, Satoshi Ōmura
The Journal of Antibiotics
A new natural product, designated iminimycin A, was isolated from the cultured broth of a streptomycin-producing microbial strain, Streptomyces griseus OS-3601, via a physicochemical screening method using HP-20, silica gel and ODS column chromatographies and subsequent preparative HPLC. Iminimycin A is an indolizidine alkaloid, containing of an unusual iminium group and a cyclopropane ring with a triene side chain. The absolute configuration of iminimycin A was elucidated by NMR studies and electronic circular dichroism analysis. Iminimycin A shows anti-bacterial activity against Bacillus subtilis, Kocuria rhizophila and Xanthomonas campestris pv. orizae, and cytotoxic activity against HeLa S3 and Jurkat cells with IC50 values of 43 and 36 μM, respectively.
Circular dichroism, Absolute configuration