PROTEINS OF THE COTTONSEED. ~ By D. Breese Jones and Frank A. Csonka. lARsT~ac'r.]
BY extracting finely ground cottonseed kernels (hull-free) with benzene, nearly all of the fatty and resinous substances and much of the coloring material are eliminated, thus facilitating the subsequent extractio n of the proteins by different solvents. For this purpose benzene is far superior to ether.
Two globulins, designated as a-and 13-globulinS, have been separated from a sodium chloride extract of cottonseed in yields of 2.59 and I6.OO per cent., respectively. The oL-globulin was precipitated by the addition of ammonium sulphate to o.4 to 0.5 saturation. It coagulated at 95-97 ° C. The E-globulin separated at a saturation of o. 7 to o.8, but only when the extract had been previously diluted with water. It coagulated at 92-93 ° C.
Two preparations having similar properties and composition were separated from the sodium chloride extract by heating to 62 ° and 85 ° C. These fractions yielded 68.2 and 67.52 per cent. of ash, which had the following percentage composition: P oOs, 57.29; CaO, 9.7I; MgO, I6.62; and Na20, 13.9o.
A pentose protein was also isolated (2.o8 per cent.), which contained 16.57 per cent. of pentose, o.194 per cent. of phosphorus, and 12.64 per cent. of nitrogen.
The distribution of nitrogen in the proteins isolated was determined according to the Van Slyke method.
A small quantity of a substance having the properties of a glutelin was also isolated.
An attempt to isolate a nucleic acid gave negative results.