May 15,1925 
Amino Acids and Polypeptides in Rye Kernels 
993 
It seemed of certain interest to ex¬ 
tract the amino acids of the flour sam¬ 
ples directly with alcohol instead of in¬ 
directly, as was done in the experiments 
described above. Hence definite quan¬ 
tities of flour were extracted with boil¬ 
ing 92 per cent alcohol, the extracts 
being separated by suction on a Buch¬ 
ner funnel from the residues, which were 
once more extracted in the same man¬ 
ner. The alcohol was removed from the 
combined extracts by distillation in a 
vacuum. The residues were alternately 
treated with ether (to remove fat) and 
hot water, and the ethereal and aqueous 
extracts separated in a separatory fun¬ 
nel. The aqueous extract was treated 
several times with small quantities of 
ether, while the ethereal extract was 
treated repeatedly with small quantities 
of water. The combined aqueous ex¬ 
tracts, which contained the amino acids, 
were kept on the water bath for some 
time in order to remove some ether 
present, whereupon they were filtered. 
The solution was now slightly acidified 
with acetic acid and treated with 10 
per cent tannic acid. The precipitate 
formed (chiefly protein) was filtered off, 
the filtrate was concentrated and made 
up to a definite volume, which was then 
treated with phosphotungstic acid in 
the manner already described. The 
filtrate from the phosphotungstic-acid 
precipitates was then treated with cal¬ 
cium hydroxide to slight acidity, then 
with barium hydroxide to alkalinity, 
saturated with carbon dioxide, boiled, 
filtered, the filtrate being concentrated 
under diminished pressure to 100 c. c. in 
two 20 c. c. portions, of which nitrogen 
was estimated according to Kjeldahl’s 
method, while 50 c. c. were used for 
formol-titration. In this manner it was 
found that North Dakota No. 959 con¬ 
tains 19.95 per cent, 20.90 per cent, on 
the average 20.43 per cent, of mono¬ 
amino nitrogen; while Reg. Rosen con¬ 
tains 35.51 per cent, 34.63 per cent, on 
the average 35.07 per cent, of mono¬ 
amino nitrogen, when calculated on the 
basis of the alcohol-soluble nitrogen. 
These results, while not strictly com¬ 
parable with those obtained with the 
aqueous extract, confirm in a general 
way the conclusion drawn from Table 
III that the ungerminated kernels of 
the rye varieties contain appreciable 
quantities of free amino acids. 
Table IV .—Distribution of the nonyrotein nitrogen in the ungerminated kernel of 
wheat , oats, and corn 
Variety of cereal 
Nitro¬ 
gen of 
acid 
amides 
1 
Nitro- j 
gen of 
amino 
acids ; 
Pep¬ 
tide 
nitro¬ 
gen 
Variety of cereal 
Nitro¬ 
gen of 
acid 
amides 
Nitro¬ 
gen of 
amino 
acids 
Pep¬ 
tide 
nitro¬ 
gen 
Percentage of oven-dried 
Per 
Per 
Per 
Percentage of total nitrogen 
Per 
Per 
Per 
wheat kernel: 
cent 
cent i 
cent 
of oat kernel—Continued. 
cent 
cent 
cent 
Fultz___ 
0.026 
0.032 
0.084 
Iowar_ 
1.93 
2.35 
3.49 
Kanred_ 
.053 
.066 
1 . Ill 
Winter Turf 
1.80 
1.65 
2.15 
Kubanka_ 
.052 
.041 
.155 
Percentage of water-soluble 
Marquis__ 
.058 
.054 
! .151 
nitrogen of oat kernel: 
Percentage of total nitrogen 
Swedish Select_ 
13.69 
17.39 
28.71 
of wheat kernel: 
Victory_ ___ 
10.86 
15.08 
27.16 
Fultz_ 
1.46 
1. 77 
4.67 
Iowar_ 
12.18 
14.87 
22.03 
Kanred_ 
1.88 
2.34 
3.89 
Winter Turf 
15.01 
13. 79 
17.88 
Kubanka__ 
1.72 
1.35 
3.13 
Percentage of oven-dried 
Marquis__ 
1.91 
1.77 
4.98 
maize kernel: 
Percentage of water-soluble 
Four County Corn_ 
.032 
.045 
.069 
nitrogen of wheat kernel: 
17. S. Selection No. 77_ 
.019 
.040 
.050 
Fultz__ 
8. 76 
10.66 
28.09 
Hall Gold Nugget Selec¬ 
Kanred_ _ 
12. 99 
16. 25 
26.86 
tion No. 193_ 
.021 
.051 
.036 
Kubanka_ 
12. 61 
9.91 
37.76 
Percentage of total nitrogen 
Marquis_ __ __ 
12.33 
11.46 
32.20 
of maize kernel: 
Percentage of oven-dried oat 
Four County Corn_ 
1.88 
2.65 
4.06 
kernel: 
TJ. S. Sleection No. 77_ 
1.19 
2. 52 
3.14 
Swedish Select__ 
.051 
.064 
1 .106 
Hall Gold Nugget Selec¬ 
Victory_ __ 
.029 
1 .040 
1 .073 
tion No. 193 
1.44 
3.49 
2.47 
Iowar_ 
.046 
; .057 
.084 
Percentage of water-soluble 
Wintei Turf_ 
! .027 
j .025 
, .032 
nitrogen of maize kernel: 
Percentage of total nitrogen 
Four County Corn__ 
15.61 
21.97 
34.07 
of oat kernel: 
U. S. Selection No. 77_.__ 
12.18 
26.67 
32. 79 
Swedish Select_ 
1.95 
2.48 
4.10 
| Hall Gold Nugget Selec- 
Victory. ... ...__ 
1.45 
2.02 
3.63 
i tion No. 193 
11.20 
26.95 
19.17 
j 
