Studies on Kitol. II1. The Effect of Sunlight,
Air and Heat on the Vitamin A and Kitol Fractions
Tadashi Tawara and Ryusuke Fukazawa
In the 1 st Report, the separation of Vitamin A and kitol fractions

from unsaponifiable ip.atter of a whale liver oil was described. In order torefine kitol, it became necessary to know its properties, chiefly its stability,
and the effect of sunlight, air and heat on these two fractions wereexamined.
1) The sunlight has a. considerable effect on both fractions. Direct radiation of sunlight on 0.1% alco]J.olic solution of Vitamin A fraction destroyed
one-half the amount of Vitamin A in 3 hours and that on kitol fraction
destroyed one-half of it in 4 hours.
2) Continuous passage of air through 0.1% alcoholic solution of kitol fraction showed no marked effect on kitol but the same process on Vitamin A
fraction resulted in the destruction of about 2/3 the amount of Vitamin A
present after 5 hours.
3) Boiling 0.1% alcoholic solution of kitol did not show any damage tokitol in 12 hours but the same treatment on Vitamin A fraction resultedin the destruction of ea. li7 the amount of Vitamin A.
As a result, it can be stated that Vitami A is very unstable toward·sun light and air, and is slightly effected by heat. Kitol, on the otherhand, is fairly stable against heat and oxygen but is considerably sensitive
to light.
EXPERIMENTAL
The Vitamin A and kitol fraction obtained by the method as describedm Report I were dissolved in absolute alcohol to obtain a 1% solution,
respectively. With this solution, following experiments were carried out
the amount of Vitamin A and kitol remaining in the respective solutions
were determined by measuring the extinction coefficient at 290 mµ for kitol
and at 328 mµ for Vitamin A.

1) The Effect of Light
30 cc. each 0.1% alcoholic solution of Vitamin A and kitol fractions were

The Effect of Sunlight, Air and Heat on the Vitamin A and Kitol Fractions

93

placed in 5 graduated test tubes (dia. ea. 1.3 cm, length ea 21.5 cm; co!orless, hard glass) each and after being stoppered, were radiated to direct
sunlight (on 6th September 1949. Fine. From 1200 to 1700). One test tube
each of Vitamin A and kitol fractions were taken every one hour and thevalues were determined. After radiation was completed, the content of thetest tuve was diluted with absolute alcohol to bring the concentration to
0.002% and the extinction coeffecient was measured with Carl Zeiss'
spectrophotometer, that for Vitamin A fraction at 328 m11, and for kitol
fraction at 290 mp. The results of the measurements are shown in Table
I and Fig. A.
Table I.

The Influence of Sunlight(Vitamin A Fraction)

0 hr.

Radiation time

1 hr.

2 hrs.

3 hrs.

III

El% 328mµlcm

417

312

278

228

--------III

4 hrs.

I.156

jI

5 hrs.
125(Kitol Fraction)--f%--0.

E lcm290mµ

500

417

278385Fig

243192A

600

E 1lcm% 328mt'or
E 1% 290mu

l=

I ""'
400

500''

'~

Kitol fraction'' ',...............

2002.. .

"'"" ..........

'41000Vitamin A fraction---5005---houre2)

The Effect of Heat (78°C)
500 cc. each of 0.1% .alcoholic solutions of both fractions were taken
into l /. Erlenmeyer flask and boiled with a reflux co:1denser in a boilingwater bath (78°C). After each 2 hours period, the solution was slightly
cooled and 30 cc. of .it was drawn out for testing. This was diluted to0.002% strength with absolute alcohol and determinations made with
spectrophotometer. Results are showri in Table II and Fig. B.

94

Tadashi Tawara and Ryusuke Fukazawa
Table IT.

The Influence of Heat (78°C)(Vitamin A Fraction)

Heating time

0 hr.

2 hrs.

4 hrs.

E1% 328mµ!cm417417385

I 6 hrs. I 12 hrs.
I360

360

500500(Kitol Fraction)
E 1 % 290mµ!cm

500

500500Fig. B
600

E 1 % 328mµ!cm'°°or
E1 % 290mµlcm

400I

Vitamin A fraction---------------·~

Kitol fraction,...__,oo200

100204681012houre3) The Effect of Air
15 cc. each of 0.1% alcoholic· solution of both fractions were taken in
the graduated test tubes (as described above), and the air was passed
through this solution. of the extent of its surface is continueing constantly
noise by means of a glass tube measuring ea. 0.5 mm. in inside diameter.
This procedure was carried out from l' to 5 hours. When the passage
was stopped, each glass tube was washed with little alcohol and thiswashing was added into the glass tube and the volume brought correctlywith absolute alcohol to 15 cc again (alcohol evaporated ea. 1.5 cc. per hour
during passage of air). Absolute alcohol was further added to thi~ solution
to make it a 0.002% solution and the value were deterlll,ined as previously.
Results are shown in Table ill and Fig. C.
Table ill.

The Influence of Air(Vitamin A Fraction)
Passage time

0 hr.

. E1% 328mµlcm

417II

1 hr.
417

I

2 hrs.

3 hrs•

4 hrs.

385

360

333455455

5 hrs.

I125(Kitol Fraction)
E1% 290mµ!cm

500

500455455

The Effect of Sunlight, Air and Heat on tl1e Vitamin A and Kitol Fractions
Fig. CE1lcm% 328m"ror
E1% 290mulcm

'600
500
400

----

Vitamin A fraction-- - - --........

~~-·······················

Kitol fraction~.500\200\100024----hot1rs

595