L-Tenuazonic acid, a new inhibitor of Paenibacillus Larvae

GALLARDO, G.; PEÑA, N.; CHACANA, P. A.; TERZOLO, H. R.; CABRERA, G.

WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY

Springer Netherlands

Año: 2004 vol. 20 p. 609 - 612

0959-3993

A search for bioactive compounds, inhibitors of Paenibacillus larvae, the causal agent of American foulbrood, ahoneybees’ disease, was carried on. Extracts of two fungal strains, Alternaria brassicicola and Alternaria raphani, isolated from pollen collected from beehives, exhibited a speci.c inhibitory activity against this bacterium. From these extracts and by means of chromatographic steps and bioassay-guided fractionation, three tetramic acids were isolated. The compounds were identi.ed by spectroscopic methods and the absolute stereochemistry was chemically determined. L- Tenuazonic acid was shown to be responsible for the antibiotic activity. This compound showed a MIC of 32 lg/ml, comparable with that of oxytetracycline, an antibiotic currently used for the prevention of American foulbrood.