Chemical studies on actinoxanthin.

The antitumor protein actinoxanthin exhibits high inhibitory activity against a number of gram-positive bacteria and some strains of transplantable leucoses and related tumors. Actinoxanthin was shown to consist of a single polypeptide chain crosslinked by two disulfide bonds and to contain 107 amino acid residues. Reduced and alkylated actinoxanthin was digested with chymotrypsin, thermolysin and trypsin.