Oxetin, a new antimetabolite from an actinomycete. Fermentation, isolation, structure and biological activity.

Abstract

A new amino acid-antimetabolite, oxetin, was isolated from a fermentation broth of a Streptomyces sp. OM-2317, a soil isolate. The chemical structure was elucidated as (2R,3S)-3-amino-2-oxetane carboxylic acid by analysis of the spectral data and by X-ray diffraction methods. The antibiotic is the first natural product possessing an oxetane ring. Certain microorganisms [Bacillus subtilis and Piricularia oryzae] were inhibited by oxetin only when cultivated in minimal media. The inhibitory action was reversed by several amino acids such as L-Ile, L-Met, L-Val and L-Glu. It also exhibited herbicidal activity [against alfalfa (Medicago sativa) and turnip (Brassica rapa)] and inhibited glutamine synthetase from spinach leaves.