Nov. 15, 191S Gossypol, the Toxic Substance in Cottonseed Meal 



283 



TOXICITY OF AN ALCOHOLIC EXTRACT OF OASOLINE-ETHER-EXTRACTED 

 KERNELS (FEED 330) 



The solution obtained by treating gasoline-ether-extracted cottonseed 

 kernels with hot alcohol was evaporated to a small volume over a water 

 bath. The extract was about 10 to 12 per cent of the kernels. As the 

 solution was concentrated, it separated into a yellowish layer (probably 

 chiefly raffinose) and a reddish black resinous layer. The concentrated 

 solution was mixed with corn meal, dried, and pulverized. This feed had 

 a yellow-brown color and a very bitter taste. It was fed to two rabbits 

 (969 and 970) in amounts equivalent to 50 gm. of cottonseed daily. It 

 did not prove to be toxic, although the rabbits lost slightly in weight 

 and frequently left part of their feed, possibly on account of its bitter 

 taste. On the fourth day of feeding a slight diarrhea was noticed in 

 both animals. They were quite normal after having been on the feed 

 for 26 days, when it was discontinued (Table XIV). 



Table XIV. — Results of feeding an alcoholic extract of gasoline-ether-extracted cottonseed 

 kernels {feed 330) to rabbits 



Weight of rabbit. 



Equiva- 

 lent of 

 feed eaten 

 as kernels 



Number 



of days 



fed. 



969. 

 970. 



Gm. 

 1.530 

 1,650 



Gm. 



1,475 



1,515 



Gm. 



55 

 135 



Gm. 

 243 



000 

 900 



Lived. 

 Do. 



These two animals were then fed on the material from which the 

 extract was obtained (see feed 316). 



The presence of some gossypol due to the incomplete extraction by 

 ether doubtless causes the slight toxicity of feed 316. 



The nontoxicity of feed 330 may be explained on the assumption that 

 the gossypol, extracted from feed 316 by alcohol, undergoes oxidation 

 during the process of extraction or evaporation. This point needs fur- 

 ther study (see feed 338). 



Both the alcoholic extract and oxidized gossypol possess a bitter 

 taste, whereas gossypol and gossypol "acetate" are tasteless and odorless. 



ARE OTHER TOXIC SUBSTANCES PRESENT? 



Although the feeding experiments show that gossypol is very poisonous, 

 produces symptoms of cottonseed-meal poisoning, and affords a satis- 

 factory explanation of the toxic properties of cottonseed meal, we do 

 not claim to have made a complete study of the cottonseed from the 

 standpoint of toxicity. The following problems are still unsolved : 



(i) To exactly what extent does gossypol occur in cottonseed — i. e., 

 in the petroleum extract and in the ether-extracted residue — and is 

 gossypol the only toxic substance of like nature in the gossypol extract ? 



