Isolation of β-Phenyllactic acid related compounds from Pseudomonas Syringae

Three metabolises, weakly phytotoxic on apple and bean leaves, have been isolated from Pseudomonassyringae pv papulans culture filtrates and their structures established by spectroscopic analysis. The trivial names of papuline, o-hydroxynitropapuline and papulinone were assigned to the three active substances. Papuline was the methyl ester of β-phenyllacticacid, and o-hydroxynitropapuline was its meta-hydroxy-para-nitro disubstituted derivative. Papulinone, a new β-lactone structurally related to fl-phenyllacticacid, was identified as 4-(1-hydroxy-2-phenylethyl)-4-carbomethoxyoxyetan-2-one.