Thermal Behavior Investigation of L-Hydroxyproline Involved in Collagen Synthesis

In the present work, the use of various calorimetric methods (combustion calorimetry, mixing (C80), differential scanning calorimetry (DSC) and coupled method thermogravimetry-differential scanning calorimetry (TG-DSC)) were illustrated as a powerfull techniques that can provide valuable thermodynamic properties of an important component of collagen, namely L-hydroxyproline (4-hydroxy-L-proline). The thermal behavior of 4-hydroxy-L-proline was studied in the temperature range between 20 ºC to 500 °C, the transformation (melting-decomposition) point, weight loss, purity and the associated thermal effects were determined from the DSC, TG-dTG curves respectively. The values of 4-hydroxy-L-proline enthalpies of combustion and formation in solid state were calculated; information about the thermodynamic stability were obtained. Spectral characterization of the sample applying Fourier Transformed Infrared (FT-IR) method was performed. The thermal effects of the amino acid solution in water at 25 °C were calculated.