Identification of hypoxanthine as the major compoenet of a chromatographic fraction of transfer factor.

A chromatographic fraction of transfer factor capable of transferring delayed hypersensitivity has been shown by us and recently confirmed by others to elute from a Sephadex G-25 column in a peak after the total column volume. The chemical composition of this fraction (TFc) was determined using fractions prepared in the same manner as preparations previously shown to have biologic activity. The major component in this fraction has been identified as hypoxanthine by identical behavior in paper, ion exchange, and gel permeation chromatography systems as well as by comparison of ultraviolet (uv), nuclear magnetic resonance (NMR) and infrared (IR) spectra of the column purified material with the spectra of crystalline hypoxanthine. In addition, the uv absorption of TFc can be converted quantitatively to uric acid by incubation with xanthine oxidase. Possible explanations for this observation include: 1) the material responsible for transfer of delayed hypersensitivity may be degraded and absent from these preparations, 2) the antigen specific component may constitute a very minor component of this fraction while hypoxanthine is responsible for some of the reported non-specific effects of transfer factor, and 3) the antigen specific transfer factor material does not elute in this fraction.