The productions of CO in all samples were irradiationdose dependent. Glycine, asparagine, and glutamine were the major sources of CO production among amino acids, and glyceraldehydes, pyruvate, and α -ketoglutarate were the major sources of CO among glycolysis intermediates. Phosphatidyl choline, phosphatidyl ethanolamine, and lysophosphatidyl choline produced the greatest amounts of CO among the phospholipids. The amounts of CO produced from these sources were significant, and the production of gas compounds via radiolytic degradation appears to be closely related to the structure of molecules.