POLYTTNS/VTTTRATED FATTY ACTDS 785 



fieiency disease produced by the rigid exclusion of fat from the diet, were 

 linoleic acid (9,12-octadecadienoic acid) linolenic acid (9,12,15-octadeca- 

 trienoic acid) and arachidonic acid (5,8, 1 1 , l4-eicosatetraenoic acid) . Hinno 

 et al.^'^ reported that a docosahexaenoic acid of unknown structure possesses 

 similar biologic activity. Moreover, methyl linoleate and linoleyl alcohol 

 (9,12-octadecadienol) were found by Turpeinen^*-^^ to possess biopotency, 

 presumably because they are converted to arachidonic acid in the body in 

 the course of their intermediary metabolism. 



On the other hand, several poljamsaturated acids have been found to be 

 biologically inactive in respect to the fat-deficiency syndrome. Included 

 in this category are the following acids: linolelaidic acid {trans-^-trans-Vl- 

 octadecadienoic acid), as reported by Burr,^ 9,11-linoleic acid (9,11- 

 octadecadienoic acid), as recorded both by Burr^ and by Thomasson,^" 

 who employed a new bioassay procedure. 10,12-Octadecadienoic acid 

 was likewise reported by the latter investigator to be biologically inactive. 

 Other dienoic acids concerning which data are available include 2,6- 

 phytadienoic," which is inactive; 10,13-nonadecadienoic acid, reported 

 as inactive by Karrer and Koenig,i^ and as possessing 9% of the activity 

 of linoleic acid by Thomasson;^^ and 11,14-eicosadienoic acid, also listed 

 as practically inactive by Karrer and Koenig, ^'' but to which a value of 

 43% of that of linoleate was attributed by Thomasson.^^ Sorbic acid 

 (2,4-hexadienoic acid) has likewise been reported b}^ Deuel, et al.^^ to be 

 biologically inactive. 



Holman^^ and Privett, Pusch, and Holman^" have published a series 

 of studies demonstrating the bioimpotence of trans isomers, and Holman 

 and Greenbergi- reported that of oxidized and conjugated linoleate. 



Thomasson^^ noted that ordinary linolenic acid (9,12,15-octadecatri- 

 enoic acid), formerly considered as possessing biopotency equal to that of 

 linoleic acid, under certain conditions, is actually practically inactive 

 (9%) when tested by the new bioassay method of the author; on the 

 other hand, 7-linolenic acid (6,9,12-octadecatrienoic acid) is considered 



" E. M. Hume, L. C. A. Nunn, I. Smedley-MacLean, and H H. Smith, Biochem. J., 

 S;?, 2162-2177 (1938). 



'* O. Turpeinen, Proc. Soc. Exptl. Biol. Med., 37, 37-40 (1937). 

 15 0. Turpeinen, /. Nutrition, 15, 351-366 (1938). 

 1^ H. Thomasson, Intern. Rev. Vitamin Research, 25, 62-82 (1953). 

 1^ P. Karrer and H. Koenig, Helv. Chim. Acta, 26, 619-626 (1943). 



18 H. J. Deuel, Jr., R. B. Alfin-Slater, C. S. Weil, and H. F. Smyth, Jr., Food Research, 

 1.9, 1-12(1954). 



19 R. T. Holman, Proc. Soc. Exptl. Biol. Med., 76, 100-102 (1951). 



20 O. S. Privett, F. J. Pusch, and R. T. Holman, Arch. Biochem. Biophys., 57, 156-162 

 (1955). 



