Oil activated by irradiation. II. Separation into an antirachitic and an inactive fraction.

In previous communications 1,2 it has been reported by us that inert vegetable oils, such as linseed or cotton seed oil, can be endowed with antirachitic properties by means of irradiation with ultraviolet rays, and furthermore that the same property can be communicated to lettuce or to growing wheat by this form of radiation.

It is well-known that the antirachitic principle of cod liver oil is contained in its unsaponifiable fraction and that the saponifiable fraction is inert (Zucker). It seemed therefore of interest to ascertain whether the activated vegetable oil could be separated into similar fractions. A preliminary test showed that the unsaponifiable fraction of cotton seed oil was unable to protect rats which were placed on a low phosphorus rickets-producing diet the same was found to be true in respect to linseed oil. When, however, irradiated linseed oil was fractioned, it was found that 0.1 gm. of the unsaponifiable fraction was sufficient to confer protection. The criterion of its efficacy was the absence of microscopic lesions at the costochondral junctions. Furthermore the blood of these rats contained more than twice as much inorganic phosphorus as the blood of similar rats which had received the non-irradiated oil. It would seem that irradiation of the vegetable oil had produced a substance similar in its properties to that in cod liver oil.