202 III. CHEMTSTRY OF NEUTRAL FATS 



cosicle of sesamol.^"^ It is suggested that the possible slow transformation of 

 sesamolin to sesamol creates an especially effective environment to prevent 

 the development of rancidity. On the other hand, another closely related 

 compomid, sesamin, is devoid of antioxidant action. *^^ A potent antioxi- 

 dant, presumably sesamol, is concentrated by molecular distillation.^*"^ 



(d) N ordihydroguaiaretic Acid (NDGA). Nordihydroguaiaretic acid 

 has proved to be an excellent antioxidant. Its protective action on fats 

 was first described by Lundberg and associates,^"'' and its use for this pur- 

 pose is the basis for a public service patent.^"^ This product is prepared by 

 the extraction of the desert plant, Larrea divaricata, which is commonly 

 kno^^^l as the creosote bush. The plant is indigenous to the southwest 

 desert areas of the United States and of Mexico. It can readily be pre- 



Nordihydroguaiaretic acid 



pared by a method described by Gisvolcl^"^ and is available commercially.^^" 

 When added to lard, this compound imparts no undesirable flavor, odor, 

 or color to the product^^^; lard so treated has been reported to remain sweet 

 for over a year, as determined by organoleptic tests.^"^ Cream to which 

 0.00125 or 0.005% of NDGA was added did not develop an oxidized 

 flavor when frozen over an 11-month period.^^^ 



Nordihydroguaiaretic acid is a white crystalline solid, melting at 184- 

 185°C., which is slightly soluble in water and dilute acids, moderately 

 soluble in hot benzene and xylene, and very soluble in diethyl ether, alco- 

 hol, and glacial acetic acid.^°^ It dissolves sparingly in fats^^^ to the extent 

 of 0.5%. NDGA is 2,3-bis-(3,4-dihydroxybenzyl)-butane (4,4-(2,3-di- 

 methyltetramethylene))-dipyrocatechol. Schroeter and co-workers^" first 

 synthesized the compound in 1918. Haworth et al.^^^ synthesized the di- 

 methyl ether, while Lieberman, Mueller, and Stiller"^ have recently re- 



505 J. Boeseken, W. D. Cohen, and C. J. Kip, Rec. trav. chirn., 55, 816-820 (1936). 



506 D. P. Grettie, U. S. Patent No. 2,052,289 (Aug. 25, 1936). 



507 W. O. Lundberg, H. O. Halvorson, and G. O. Burr, Oil & Soap, 21, 33-35 (1944). 



508 W. M. Lauer (to U. S. Secretary of Agriculture), U. S. Patent No. 2,373,192 (Apr. 

 10, 1945). 



500 O. Gisvold (to Regents, University of Minnesota), U. S. Patent No. 2,382,475 (Aug. 

 14, 1945). 



510 Manufactured by Wm. J. Stange Co., Chicago 12, 111. 



511 J. W. Stull, E. 6. Herried, and P. H. Tracy, /. Dairy Sci., SI, 1024-1028 (1948). 



512 W. O. Lundberg and H. O. Halvorson, Proc. 7ns<. Food Tech., 1945, 115-125; Chem. 

 Abst., 40, 6847 (1946). 



513 G. Schi-oeter, L. Lichtenstadt, and D. Irineu, Ber., 51, 1587-1613 (1918). 



51^ R. D. Haworth, C. R. Mavin, and G. Sheldrick, /. Chem. Soc, 1934, 1423-1429. 

 515 S. V. Lieberman, G. P. Mueller, and E. T. Stiller, J. Am. Chem. Soc, 69, 1540-1541 

 (1947). 



