K. P. BASU AND K. P.
MUKHERJEE
235
neous hydrolysis on standing with the molybdate
reagent for half an hour at room temperature
(28º—30ºC.) showing that it consisted of labile
phosphoric ester. The inorganic phosphorus in the
trichloracetic acid filtrate was wholly precipitated
by barium. Hence the value for ester phosphorus
obtained by subtracting the inorganic phosphorus
from total phosphorus extracted by trichloracetic
acid was practically the same as the value for
barium soluble labile phosphoric ester. From
some reactions done by us as indicated in the
experimental part this phosphoric ester appears
to consist mainly of creatine phosphate. Using
the methods of Eggleton and Eggleton [1929]
with minor modifications Acharya and Devadatta
[1940, 1941] could also obtain only creatine and
lactose in the organic phosphorus compounds in
buffalo's milk.
The phosphorus distribution in milks of
different animals can be best seen from Table VI
n which the mean values of different fractions
are expressed as percentages of total phosphorus.
For the value for ester phosphorus the average of
barium soluble phosphorus and that obtained as
the difference of total acid soluble P and inorganic
phosphorus is given.
TABLE VI
Showing the mean values of various phosphorus
fractions of milks of different animals expressed as
percentages of total phosphorus in milks
Name of
animal
Cow
Sheep .
Goat
Buffalo .
Human milk
Total P
mg/100
c.c.
97.6
99.5
105
125.3
35.25
Trichloracetic acid
soluble P.
Total
75.2
69.6
77.1
70.6
71.6
inor-
ganic
64.6
57.3
64.6
53.5
19.8
Ester
10.8
12.5
12.7
17.2
52.7
Trichloracetic acid
Insoluble P.
Total
24.7
30.2
22.9
29.3
28.3
Lipin
7.5
11.1
6.4
13.9
13.4
Casein
17.1
19.2
16.3
15.4
14.8
Remarkable is the high ester phosphorus content
(52.7 per cent of total phosphorus) of human
milk which is comparatively poorer in total phos-
phorus so that the absolute amount of ester
phosphorus per 100 c.c. human milk is not much
higher than in milk of other animals and is
lower than in buffalo milk.
In buffalo milk Acharya and Devadatta found
some organic phosphorus—about 10 per cent of
the total—in the barium precipitate. We could,
however, detect none and nor could Ananta-
krishnan in ass's milk. The value for lipin P
obtained by Acharya and Devadatta in buffalo
milk also appears to be too low.
SUMMARY
The phosphorus partition in milks of cow, goat,
sheep, buffalo and human beings in different
fractions, namely, trichloracetic acid soluble in-
organic and organic (labile) ester P and trichlor-
acetic acid insoluble lipin and casein phosphorus
has been investigated. Special attention has been
paid to the trichloracetic acid soluble fraction.
Adenyl-pyrophosphate, hexose diphosphate and
hexose monophosphate were found to be practically
,absent from cow's milk. The whole of the barium-
non-precipitable phosphorus of the trichloracetic
acid extract was found to consist of labile phos-
phoric ester. The latter appears to be creatine-
phosphate. The inorganic phosphorus in the
trichloracetic acid filtrate is wholly precipitated by
barium.
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