抄録
As described in the previous theme, the purified substance, hypoxanthine, was extracted from the circulating blood in the early stage after the second sensitization of typhoid vaccine in rabbits, but it was shown that it has no immunological effects.
Then that is why the method of purification was re-examined in this paper. The effective serum separated from blood was treated with Amberlite IR 120 H+ resin (100-200 meshes) or Dowex 50H+ resin (200-300 meshes) and finally, a substance which had been eluted from these resins together with hypoxanthine was separated. This new substance had the immunological properties and an absorption maximum at 24μE like hypoxanthine, but, on the other hand, contained ribose moiety. The substance was re-crystallized from methanol and identified with inosine by the data of paper-chromatography and of intra-red spectrum etc. The purified substance, inosine, as compared with the essential and effective serum (inosine content in serum was calculated by measuring of the optimal density at 249 mμ) separated from the circulating blood in the early stage after the second sensitization of typhoid vaccine in rabbits, was a little weaker in activity.
Anyhow, possessing the immunological and biological properties of the antibody promoting factor which had been observed several years before, isonine was indentified with one of the antibody promoting factor itself.
