Syntheses of the P-methylase substrates of the bialaphos biosynthetic pathway.

Genetic studies suggest that either N-acetyldemethyl phosphinothricin (1, N-AcDMPT) or N-acetyldemethyl phosphinothricin tripeptide (2, N-AcDMPTT) is the substrate for the P-methylation reaction in the biosynthesis of phosphinothricin tripeptide (PTT), which is widely used as an herbicide. To study the mechanism for this unique P-methylation reaction catalyzed by the BcpD protein and the functions of the unusual nonribosomal peptide synthetases involved in PTT biosynthesis, this work reports the chemical syntheses of 1 and 2.