Isolation and purification of a 316 Da preformed compound from strawberry (Fragaria ananassa) leaves active against plant pathogens

An antibiotic called fragarin showing activities against bacterial and fung al plant pathogens was isolated and purified by FPLC chromatography from th e soluble fraction of strawberry leaves. The molecular weight value determi ned by mass spectrometry is 316 Da. Fragarin remains fully active after pro tease treatment or alkaline hydrolysis at 100 degrees C for 20 min, Biologi cal and chemical analyses suggest that fragarin may be a new type of an ant imicrobial preformed compound - phytoanticipin - and would constitute a pri mary non-specific barrier of strawberry defense. (C) 1999 Federation of Eur opean Biochemical Societies.