264 Journal of Agricultural Research voi. v, no. 7 



OCCURRENCE AND PROPERTIES OF GOSSYPOL 



If the cottonseed kernel is examined with a lens, many small yellowish 

 brown to black spots may be seen (PI. XXV). They are referred to by 

 Hanausek (1907, p. 367) as "secretion cavities" in the following state- 

 ment: 



Distributed among the mesophyll cells [of the cotyledons] are procambium bundles 

 and globular, lysigenous secretion cavities {se) 100 — 400/i diameter. The lysigenous 

 character of these cavities when mature is quite clearly evident. The tissue which 

 ^rrounds them consists, in its outer portion, of tangentially flattened, very thin- 

 walled cells, and within the last a mucilaginized layer in which the traces of the cell 

 walls are still evident. This colorless mucilage layer, which treatment with hydro- 

 chloric acid and, after washing with water, with potash brings out as a yellow, folded, 

 and laminated mass, encloses the greenish-black, opaque secretion {v). Since the 

 mucilage layer is soluble in water, the secretion flows out from the sections laid in 

 water in the form of a thick emulsion consisting of a colorless mass containing minute 

 dark-colored grains (resin?) in lively molecular motion. Chlorzinc iodine colors the 

 secretion red-brown, sulphuric acid dissolves it to a thick turbid fluid of a blood-red 

 color. Ammonia colors the liquid greenish yellow without destroying the emulsion. 

 Potash also imparts a green color. 



They are designated by Watt (1907, p. 56) as "gland dots" and by 

 Balls (1912, p. 13) as "resin glands." From these glands we have 

 extracted gossypol and for clearness have alluded to them as gossypol 

 glands. Their function does not seem to be very well known. 



They occur in all parts of the cotton plant and in all varieties which 

 we have seen. They are very abundant in the cambium layer of the 

 bark of the cotton root.^ 



Gossypol was first isolated by Marchlewski (1899) from the "foots" in 

 the purification of cottonseed oil, and on account of its source and phen- 

 olic properties he proposed for it the name "gossypol," from Gossyp 

 [ium phen]ol. 



Previous to Marchlewski's work the crude substance constituting the 

 coloring matter of cottonseed oil was referred to by the older writers — 

 e, g., Hanausek (1903, p. 755) — ^as "gossypin,"^ which is described as a 

 light-brown pungent powder. 



Marchlewski (1899) proposed for gossypol the formula Ci3Hj404, with 

 C32H34O10 as an alternate formula. Among its properties as described by 

 him are the following: A beautifully crystalline yellow-colored dihy- 

 droxy phenolic substance, easily soluble in alcohol, benzene, chloroform, 

 ether, acetone, and glacial acetic acid; insoluble in water; soluble in con- 

 centrated sulphuric acid with a magnificent red color; easily soluble in 

 alkalies, the solution for the first second being yellow, after a short time 

 becoming a beautiful violet and then fading, the changes being due to 

 oxidation. The alcoholic solution gives a dark-green color with ferric 



1 Thus, we have an indication that gossypol may be the active principle of the medicinal extract of- cotton- 

 root bark. (Bouchelle, 1840.) 



' The original work on gossypin has not been located by us. 



