Complexation and physicochemical analysis of hydrophobic molecules of methyl jasmonate with Hydroxypropyl-β–Cyclodextrin

In the present study, methyl jasmonate (MeJa) was included in 2-hydroxypropyl-β-cyclodextrin (HPβCD) by grinding (M 1 ), freeze drying (M 2 ), co-precipitation + freeze drying (M 3 ) and by applying supercritical carbon dioxide (M 4 ). FT-IR/ATR, FT-Raman, TGA, and DSC analyses of the complexation products confirmed that MeJa/HPβCD complexes were formed by the four different examined methods of inclusion. FT-IR/ATR supported the inclusion, mainly based on the reduction of intensity of absorption at the wavelength of maximum absorbance of free MeJa (1733 cm -1 ), which was 27.69 au before inclusion. From these results, M 3 (2.29 au) and M 4 (0.90 au) were the most efficient techniques for complexation. TGA, and DSC analyses pointed out that the complexes formed by the methods M 3 and M 4 had the least loss of mass below approximately 305°C (the temperature that free HPβCD starts to decompose thermally). Except for M 1 , the results of antioxidant activity (AA) based on the DPPH assay revealed that the AA of the inclusion compounds were higher than that of free MeJa (α = 0.05). The best methods in terms of AA and thermal stability of the formed inclusion compounds were M 3 and M 4 .