NONVOLATILE COMPOUNDS FORMED ON THE THERMAL-DEGRADATION OF PHENYLALANINE

L-Phenylalanine was heated in liquid paraffin at 210 degrees C for 15 min. Methanol extracted 76.4% of the resulting colored material, on th e basis of absorbance measurements at 420 nm. Nonvolatile, relatively nonpolar compounds of the methanol extract were separated by reversed- phase HPLC, and two phenylalanine degradation products were characteri zed using UV-visible, IR, NMR, and mass spectrometry. They were identi fied as N-(2-phenylethyl)-3,4-diphenylpyrrole and 2-phenylethyl)-3,4-d iphenyl-3-pyrroline-2,5-dione.