Va. Basiuk et J. Douda, Analysis of less-volatile products of poly-L-valine pyrolysis by gas chromatography/Fourier transform infrared spectroscopy/mass spectrometry, J AN AP PYR, 60(1), 2001, pp. 27-40
Less-volatile products of poly-L-valine pyrolysis at 500 degreesC under nit
rogen atmosphere were analyzed by the coupled technique of gas chromatograp
hy/Fourier transform infrared spectroscopy/mass spectrometry (GC/FTIR/MS).
Of 18 compounds identified, there were one isocyanate, one unsaturated carb
oxylic acid, two ketones, three unsaturated hydrocarbons, three nitriles, f
ive amines, one linear and two cyclic amides (including valine diketopipera
zine). Comparison with the composition of less-volatile products of poly-c;
ly and poly-Ala pyrolysis, where majority of the compounds were cyclic amin
es and amides, shows that the differences between these cases is the presen
ce of an isocyanate, unsaturated nitriles, ketones and hydrocarbons in the
less-volatile fraction of poly-Val pyrolysate. For cyclic compounds, there
is a general trend to form six-membered ring systems tin particular, substi
tuted benzenes and pyridines) in the present case, whereas most cyclic prod
ucts of poly-Gly and poly-Ala pyrolysis were five-membered mono-N-heterocyc
les (substituted pyrrolidines and pyrroles). (C) 2001 Elsevier Science B.V.
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