292 H. J. ROGERS AND H. R. PERKINS 



one substance. Consequently the materials from each peak after concentra- 

 tion by adsorption on to, and elution from charcoal [19], were re-chromato- 

 graphed on columns of diethylaminoethyl-cellulose. The columns were 

 developed with a gradient of ammonium acetate at pH 6-5. Material from 

 the first peak from Dowex-i yielded only one substance containing both 

 N-acetylhexosamine and [2-^^C]-5-fluorouracil when examined on the sub- 

 stituted cellulose column whilst the second yielded two such peaks, one 

 of which was still heterogeneous. This latter peak was chromatographed 

 once more on diethylaminoethyl cellulose, the column being developed 

 this time with an increasing concentration of ammonium acetate at pH 5-0. 

 Table I shows the analysis of the compounds isolated. It will be seen 

 that I A, 2C1 and 2C2 are the fluorouridine analogues of the compounds 

 previously isolated by Park [11] from penicillin-treated staphylococci. 

 Huorouridine-diphospho-N-acetylglucosamine (2B) was also isolated: no 

 other compounds containing N-acetylhexosamine could be recognized. 



TABLE I 



Analysis of the Compounds Extracted from Staphylococcus aureus Strain 524 



WITH Trichloroacetic Acid after the Cells had been Incubated with 04 



/amole of [2-^'*C]-5-Fluorouracil 



(The molar proportions are related to the concentration of [2-^*C]-5-fluoro- 

 uracil which is taken as i 00.) 



Molar proportions 



■^-Fluoro- Phos- Glutamic ^ • ai • Muramic Glucosa- 



•' ., , . , Lysme Alanine . , 



uracil phorus acid • acid mine 



I A I • 00 



2B I 00 



2C1 I 00 



2C0 I 00 



* = Not estimated. 



It will be noted that none of the compounds contained glycine. In 

 earlier experiments in which lower concentrations (o-i /xmole/ml.) of 5- 

 fluorouracil had been used, traces of glycine were found in hydrolysates 

 from the materials in both peaks which emerged from the Dowex-i 

 columns [17]. Only very small amounts of a definite compound, however, 

 were found containing glycine, glutamic acid, alanine, and muramic acid. 

 This compound seemed no longer to be present when 5-fluorouracil was 

 present at the higher concentration in the incubation medium. 



From the above observations it seems reasonable to suppose that at 

 least part of the cell wall mucopeptide in our strains of staphylococcus is 



