AUGUST, 1937
INDUSTRIAL AND ENGINEERING CHEMISTRY
(9) Hixson and Wilkens, IND.EXG.CEXEM., 25, 1196 (1933). (10) Huber and Reid, Ibid., 18,535 (1926). (11) Karnbara, Oyamada, and Matsui, J . SOC.Chem. Ind. (Japan), Suppl. Binding, 34, 361 (1931). (12) Milligan and Reid, IND. ENG.CHEM.,15, 1048 (1923). (13) Murphree, Ibid., 15,148 (1923). (14) Reynolds, Osborne, Trans. Roy. Soc. (London), 1883. (15) Roth, 2. physik. Chem., 110,57 (1924). (16) Spencer and Meade, Cane Sugar Handbook (1929).
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(17) White, Brenner, Phillips, and Morrison; White and Brenner, Trans. A m . Inst. Chem. Engrs., 30,570 (1934). (18) White, Sumerford, Bryant, and Lukens, IND.ENG.CHBM.,24, 1160 (1932). (19) Wieselsberger, C., "GBttinger Ergebnisse," Vol. 1, p. 120. Munich, 1921. (20) Wood, Whittemore, and Badger, Chem. & Met. Eng., 27, 1176 (1922). RECEIVED February 27, 1937.
A Polyuronide 'from Tobacco Stalks The isolation and partial analysis of a polyuronide from the cured stripped stalk of Havana seed tobacco is described. Upon hydrolysis the polyuronide yields xylose as the chief sugar.
T
HE tobacco plant (Nico-
tiana h b a ~ ~ mis) u n i q u e
s e n t i a l l y t h a t introduced by O'Dwyer (7). The hemicellulose precipitate did not appear until after the addition of an equal volume of ethanol. Purification of the precipitate was accomplished by resolution, reprecipitation, and the use of Fehling's solution. After the purified substance was dried in a vacuum oven a t 50' C., it was found to have the following general properties: (a) tasteless, slightly yellow in color; (b) very slightly soluble in cold water; (c) soluble in hot water; (d) blue color when treated with iodine; (e) optically inactive, The production of a blue color with iodine is believed to be due to the presence of anhydroglucose units (3,8). Analytical data representing duplicate and triplicate determinations on the percentage furfural and uronic acid anhydrides of the original tobacco stalks and the purified hemicellulose on an ash and moisture-free basis are shown in the following table:
EMMETT BENNETT Massachusetts State College, Arnherst, Mass.
in at least two r e s p e c t s . First, few cultivated plants attain as large a growth in as short a time at so great an expense to the soil. Second, few plants of such proportions are as easily decomposed when returned to the soil. These are the chief characteristics which justify the common practice of using the stripped stalks as a fertilizer. This paper represents a portion of a study of the composition of tobacco stalks intended to reveal other possible uses for this material. In 1932 Hawley and Norman (5) differentiated the hemicelluloses on the basis of their association with Cross and Bevan cellulose. On this basis two distinct major groups are recognized-cellulosans and polyuronides. Cellulosans are structural substances found in Cross and Bevan cellulose, which do not contain uronic acids. Polyuronides are incrusting substances not found in Cross and Bevan cellulose, which contain uronic acids. The subject matter of this paper deals with the polyuronides.
Experimental Procedure The methods of analysis were as follows: Ami. This determination was made by ignition in a muffle furnace at a dull red heat. PROTEIN.Nitrogen was determined by the Kjeldahl-GunningArnold method (1) and converted to protein by the factor 6.25. FURFURAL.The A. 0. A. C . phloroglucinol method ( 1 ) was
employed.
URONICACIDANHYDRIDES. This group was determined by the method of Dickson, Otterson, and Link (4) as modified by Phillips, Goss, and Browne (9). TOTALHEMICELLULOSE. This group was determined by the method described by Buston ( 2 ) .
The entire stalk of the cured stripped Havana seed tobacco was used for analysis, with the exception of the short woody section a t the base. For the most part the portion used represents the material which is returned to the soil. The stalks were dried at 60" C., crushed, and finely ground in a Wiley mill. The ground material was extracted successively with the following solvents: ( a ) 0.5 per cent ammonium oxalate, two 12-hour periods a t 70" C.; ( b ) 5.0 per cent sodium hydroxide in 50.0 per cent aqueous alcohol , five 12-hour periods a t room temperature; ( e ) 5.0 per cent sodium hydroxide, 48 hours a t 70" C. The method of fractionation of the hemicellulose was es-
Determinations Originai Stalks Purified Hemicellulosr~ 45.20a Furfural 10.72 11.03 Uronic acid anhydrides 10.53 Total hemicellulose 20.13 Corrected for furfural from uronic acid anhydrides (6).
.....
A portion of the puritled product was hydrolyzed with 4.0 per cent sulfuric acid in a bath of boiling water for 15 hours. The acid-free sugar solution was obtained in the usual manner, and the sugars were allowed to crystallize from alcohol A second recrystallization yielded a product which gave a positive phloroglucinol test, decomposed a t 148' C., and gave an [CY]': value of +19.42". These tests would indicate that the sugar obtained by the hydrolysis of the polyuronide was xylose.
Literature Cited (1) Assoc. Official Agr. Chem., Methods of Analysis, 4th ed., 1935. (2) Buston, H. W., Biochem. J . , 28, 1028-37 (1934). (3) Campbell, W.G., Nature, 136, 299 (1935). (4) Diokson, A. D., Otterson, H., and Link, K. P., J . Am. Chem. SOC.,52, 775-9 (1930). (5) Hawley, L.F.,and Norman, A. G., IXD.ENG.CHEM.,24, 11904 (1932). (6) Norris, F.W., and Resch, C . E., Biochern. J.,29, 1590-6 (1935). (7) O'Dwyer, M.H., Ibid.. 20, 656 (1926). (8) Ibid., 31, 254-7 (1937). (9) Phillips, M., Goss, M. J., and Browne, C. A., J . Assoc. Oficiccl Agr. Chem., 16, 289-92 (1933). RBCEIVED May 3. 1937 Contribution 278 from the Massachusetts Agricultural Experiment Station.
