This paper presents an experimental study about the structural modifications of aminoacids L-leucine (C6H13NO2), L-alanine (C3H7NO2), L-aspartic acid (C4H7NO4) and glycine (C2H5NO2) after processing at high pressure and high temperature. Experiments were performed at 2.5 and 7.7GPa at 1100°C during 1min, leading to the formation of graphitic structures with low degree of crystallinity. Evidences from Raman and infrared spectroscopy, X-ray diffraction, elemental analysis (CHN) and scanning electron microscopy (SEM) suggested that the resulting graphitic nanostructures depended on the initial concentration of nitrogen and oxygen of the starting samples. The results were compared to the behavior of paraffin, which does not contain nitrogen and oxygen atoms, and 5-Azacytosine (C3H4N4O), containing nitrogen and oxygen but in a cyclic structure.