Oligo-glycine synthesis in an aqueous solution of glycine under oxidative conditions

Di- and tri-glycine were synthesized in 1M aqueous solution of glycine by bubbling for 90 hr with oxygen discharged in the path from an oxygen cylinder. The peptides were also produced by an incubation at 37 degrees C of 2M glycine solution prepared with 75% hydrogen peroxide, and the yields were traced for 200 days. The final yields were about 0.25% and 0.01% for di- and tri-glycine, respectively. The solution at 166 days of incubation was applied to a Sephadex G10 column, and the fractions around the top of the chromatogram were found to increase the intensity of ninhydrin color about 4 approximately 5 times after hydrolysis, indicating an existence of oligo-glycine. The solutions of 1M glycine and 0.5M diglycine prepared with 30% hydrogen peroxide were incubated at 37 degrees C for 38 days, and di- and tetra-glycine were detected in the yields of 0.12% and 0.33%, respectively.