SYNTHESIS OF N-ACETYLMURAMIC ACID-DERIVATIVES AS POTENTIAL INHIBITORS OF THE D-GLUTAMIC ACID-ADDING ENZYME

Compounds containing N-acetyl-D-muramic acid and (L-1-aminoethyl)phosphonic acid were designed as potential inhibitors of the D-glutamic acid-adding enzyme of the biosynthesis of bacterial peptidoglycan. 2-Acetamido-2-deoxy-3-O-[(R)-2-propionyl-(L-1-aminoethyl)phosphonic acid]-D-glucopyranose (3) was synthesized. 2-Acetamido-1,4,6-tri-O-acetyl-2-deoxy-3-O-[(R)-2-propionyl- (L-l-aminoethyl) phosphonic acid dimethyl ester]-alpha,beta-D-glucopyranose (9) was also prepared and was submitted to the MacDonald reaction in order to introduce a phosphate group on the anomeric position. A complex mixture of phosphorylated or/and methylated derivatives of 3 was obtained. They were purified by h.p.l.c. and characterized by analyses of hexosamine, amino acid and labile phosphate, and by plasma desorption mass spectrometry. Neither 3 nor its derivatives inhibited the D-glutamic acid-adding enzyme from Escherichia coli.