The phosphorus compounds of wheat starch.

tion showed that the starch grains were then completely dispersed. The starch was recovered as a fine precipitate by blowing the hot solution through a fine jet into 600 ml. of dry acetone which was vigorously stirred. The solution was decanted offand the precipitate washed by decantation with 2 x 200 ml. portions of dry acetone, finally filtered on a Buchner funnel and dried at 95-100O in a steam oven. The weight of precipitate was practically equal to that of the original starch taken. The acetone solution and washings (referred to later as 'acetone filtrate') were combined and concentrated to small bulk(50ml.) under reduced pressure at a temperature below 600. The concentrate, which contained chloral hydrate, was treated with 50 ml. water and again concentrated as before, whereby a small part of the chloral was removed. Further treatment to remove chloral hydrate by distillation with water was not carried out owing to the possibility of hydro- lysis or other decomposition of P compounds. alcohol (to avoid the formation of lumps later), 20 times the weight of 0-5 N-HCI added and the mixture shaken for 1 hr. at 15-20o. An equal volume of ethanol was added, and portions of the solution obtained on filtering off the precipitated starch were treated with (a) FeCl3 after neutralization and (b) excess of Ba(OH)2, as inthe scheme of LePage & Umbreit (1943). The Fe precipitate was materially reduced by solution in acid and reprecipitation by neutralization, so that the presence of phytin was considered to be very doubtful. The Ba precipitate contained a little inorganic P, and an organic P compound containing glycerol but no combined sugar. In all the soluble and insoluble fractions, qualitative tests for guanine, adenine and choline before and after acid hydrolysis were negative, indicating the absence of nucleotide and phosphatide. The acid-soluble P is therefore largely glycerophosphate with some inorganic P.