title: Spirotoamides A and B, novel 6,6-spiroacetal polyketides isolated from a microbial metabolite fraction library.
abstract: Two new 6,6-spiroacetal polyketides, spirotoamides A (1) and B (2), were isolated from a microbial metabolite fraction library of Streptomyces griseochromogenes JC82-1223 by screening of structurally unique compounds based on a search of spectral database. The fraction library was constructed using a systematic separation method to efficiently discover new metabolites from microbial sources such as actinomycetes and fungi. The structures of 1 and 2 were elucidated by 2D-NMR and mass spectrometric measurements. They belong to a class of polyketides, and contain a 6,6-spiroacetal core structure and a carboxamide group. The biosynthetic pathway of 1 and 2 is discussed in the text.
authors.affiliation: Chemical Biology Core Facility, Chemical Biology Department, RIKEN Advanced Science Institute, Saitama, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Nogawa
authors.forename: Shunji
authors.initials: S
authors.lastname: Takahashi
authors.forename: Akiko
authors.initials: A
authors.lastname: Okano
authors.forename: Makoto
authors.initials: M
authors.lastname: Kawatani
authors.forename: Masakazu
authors.initials: M
authors.lastname: Uramoto
authors.forename: Tamio
authors.initials: T
authors.lastname: Saito
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Osada