40 MICROBIAL CELL WALLS 



and Powell ^^ and was subsequently found in bacterial cell 

 walls.-^'^*'^^'^*^ The unknown amino sugar in the nucle- 

 otides accumulating in penicillin-treated Staphylococcus 

 aureus discovered by Park and Johnson ^^ in 1949 was later 

 found to be identical to the cell-wall amino sugar.^^ 



Muramic acid (3-O-carboxyethyl-D-glucosamine) was iso- 

 lated as a crystalline substance by Strange and Dark/^ and 

 the structure was established by the synthetic route worked 

 out by Strange and Kent,^^ starting with the N-acetyl-4 : 6- 

 O-benzylidene-a-methyl-D-glucosaminide, as shown in Fig. 8. 



Some of the properties of natural and the synthetic stereo- 

 isomers of muramic acid are summarized in Table 16. The 



TABLE 16 



Optical Rotation and Chromatographic Behavior of Natural and 

 Synthetic Muramic Acid and the Synthetic Isomer 



Average Values Derived from Sev- 

 eral Experiments 



glucosamine value T 



Optical on Zeo-Karb 



Rotation 225 Column Eluted 



Wd ^f* with 0.33 N-HCl 



Natural muramic acid +109 0.53 1.10 



Synthetic muramic acid +109 0.53 1.10 



Stereoisomer of muramic acid + 52 0.44 0.87 



* Values obtained with Whatman No. 1 paper and phenol-water 

 as solvent. 



f Values in this column have been reported by Crumpton (1958). 

 The ^glucosamine value relates the elution characteristics of the sub- 

 stance to those of glucosamine run at the same time. 



Reference, Strange, and Kent.^^ 



