202 



REPORTS Olf INVEISTIGATIONS AND PROJECTS. 



Osborne, Thomas B., Connecticut Agricultural Experiment Station, New 

 Haven, Connecticut. Grants Nos. 349 and 439. For zvork on vegetable 

 proteids. (For previous reports see Year Book No. 3, p. iii; Year 

 Book No. 4, pp. 260-262, and Year Book No. 5, pp. 214-219.) $10,000. 



Grant No. 5^9 ($5,000). — During the past year the work which was 

 described in the Year Book for 1906 as begun has been continued. Much 

 of this has already been completed and the results published or in press. The 

 accumulation of large quantities of pure preparations of a large number of 

 different proteins and the experience with complicated methods of analysis 

 have made possible much more rapid progress with these investigations. 



The results of hydrolyses of the wheat proteins which were last year 

 reported to be in press have been published in the American Journal of 

 Physiology, volume xvii, pages 223 and 231 (1906). 



A full report on the proteins of the wheat kernel has been prepared, in 

 which the work done in this laboratory during several years past has been 

 brought together with that done under previous grants, and made a con- 

 nected whole. This report has appeared as Publication No. 84 of the 

 Carnegie Institution of Washington. In addition, a new decomposition 

 product of wheat gliadin has been discovered and found to be a dipeptide 

 of proline and phenylalanine. The properties of this interesting and import- 

 ant substance have been described as follows in the American Journal of 

 Physiology, volume xviii, page 123 (1906) : 



The new substance crystallized directly from the moderately concentrated 

 solution of the decomposition products which resulted from boiling gliadin 

 with 25 per cent sulphuric acid for 10 hours. On concentration this sub- 

 stance crystallized, mixed with varying amounts of tyrosine and leucine, 

 from which it was separated by precipitation with phosphotungstic acid. 

 This precipitation was repeated until the separation was complete. 



The free acid thus obtained is very difficultly soluble in cold water, much 

 more soluble in water at 100°, and crystallizes from this solvent in long, flat 

 prisms, sometimes perfectly rectangular, more often with modified ends. 

 When filtered dry by suction, the crystals exhibit a beautiful mother-of-pearl 

 luster much resembling valine. Dried in the air, the substance contains a 

 molecule of water of crystallization, which it, for the most part, loses in 

 vacuo over sulphuric acid, completely at 120°. Analysis gave the follow- 

 ing results: 



Water : Calculated for Ci«HisO«Na • HaO 6.43 per cent 



Found 6.55 per cent 



Dried at 125°. 



