Plant growth-promoting and antimicrobial chloropyrroles from a rare actinomycete of the genus Catellatospora

Two new chloropyrroles, designated catellatopyrroles A (1) and B (2), along with 2-(2 '-hydroxybenzoyl)pyrrole (3), were isolated from a culture extract of an actinomycete of the genus Catellatospora. The structures of 1-3 were elucidated through interpretation of NMR and MS data. Compounds 1 and 2 are the first chloropyrroles substituted by an aliphatic acyl group at the 5-position. Compounds 1-3 promoted root elongation of germinated lettuce seeds at 1-10 mu M. While all compounds inhibited the growth of Gram-positive bacteria, activity against Gram-negative bacterium Rhizobium radiobacter and yeasts Candida albicans and Saccharomyces cerevisiae was varied. Compounds 1 and 2 were moderately cytotoxic against P388 cells.

Automated summary

Two new chloropyrroles, catellatopyrroles A and B, along with 2-(2'-hydroxybenzoyl)pyrrole, were isolated from an actinomycete culture extract. The structures of these compounds were determined using NMR and MS data. The chloropyrroles showed promoting effects on root elongation of germinated lettuce seeds, exhibited antimicrobial activity against certain bacteria and yeast, and demonstrated moderate cytotoxicity against P388 cells.