606 



PANTOTHENIC ACID 



Independently, in a brilliant piece of work, Snell and his associates 

 arrived,^" by isolation and synthesis, at a final identification of the LBF 

 fragment of CoA. They found it to be N-pantothenylthioethanolamine ; 

 this compound was named "pantetheine" for the sulfhydryl form and 

 "pantethine" for the disulfide form. A new and relatively simple method 

 of synthesis for pantethine was recently described by Baddiley.'*^' ^ 



NITROPRUSSIDE 

 REACTION 



*- PANTETHINE 



GROWTH OF 

 A. SUBOXIDANS 



Fig. 4. Paper chromatogram of phosphatase-treated coenzyme A (cf. ref. 18)' 

 The right-hand side represents the assay for pantothenic acid in all bound forms* 

 using Acetobacter suboxydans. 



The left-hand side represents the disulfide test by cyanide-nitroprusside spray. 



By this identification at the same time, the suKur compound in CoA 

 was identified as the decarboxylation product of cysteine, also known under 

 the name of "cysteamine", a short and handy name. The synthesis of 

 pantetheine has been studied by various workers and appears to involve a 

 condensation of pantothenic acid with cysteine. This is followed by de- 

 carboxylation of the pantothenyl-cysteine to yield pantethine eventually. 



Some differences between the synthetic compounds and substances iso- 

 lated from natural materials have been explained through a cross-linking of 

 various SH- compounds to reduced pantethine by simultaneous oxidation 



" J. Baddiley and E. M. Thain, /. Chem. Soc. 1951, 3425. 

 « J. Baddiley and E. M. Thain, /. Chem. Soc. 1952, 800. 

 « G. Medes and N. Floyd, Biochem. J. 36, 2591 (1942). 



