Thienodolin, a New Plant Growth-regulating Substance Produced by a Streptomycete Strain: I. Taxonomy and Fermentation of the Producing Strain, and the Isolation and Characterization of Thienodolin

Thienodolin, a new plant growth-regulating substance, was isolated from the fermentation broth of a streptomycete strain identified as Streptomyces albogriseolus.The active principle was extracted with ethyl acetate and purified by silica gel column chromatography and preparative HPLC. The substance showed growth promoting activity with 1.2 × 10−6–1.2 × 10−5 M treatment to rice seedlings, and inhibitory activity with 4.0 × 10−5 M treatment.