2), the observed major changes occurred in the region from 1800 to 500 cm−1 selleck inhibitor (Fig. 2b). Some IR bands of MGN had disappeared completely (1492, 1407 and 1093 cm−1) or had their intensities altered (1651, 1622, 1296, 1255, 1199

and 829 cm−1). In the complex, bands at 1651, 1622 and 829 cm−1 were observed, confirming the presence of MGN. Ferreira et al. (2010) showed that the NMR signals for H-5 and H-8 (Fig. 1b) of MGN in the complexed form underwent downfield shifts from 6.8 to 6.9 δ and from 7.4 to 7.6 δ, respectively, indicating that the aromatic hydrogen signals are influenced by the presence of β-CD in the medium. The thermal curves of MGN, β-CD and the MGN:β-CD complex are shown in Fig. 3. The DSC curve of MGN (Fig. 3a) displayed one sharp fusion endothermic peak close to 252.6 °C, corresponding

to the melting point. Neelakandan and Kyu (2009) found the melting temperature of MGN around 260 °C using the DSC technique. After MGN melting, the DSC curve indicated a thermal stability until 400 °C. In the case of β-CD (Fig. 3b), a broad endothermic signal was observed around 88.8 °C, correspondent to water loss by evaporation (t < 100 °C). A sharp endothermic signal was observed close to 295 °C corresponding to the melting point of β-CD, followed by endo-exo effects that are related to thermal degradation in 335 °C. These results agree with literature data ( Giordano, Novak, & Moyano, 2001). DSC curve of the physical 1:1 mixture of MGN and β-CD (Fig. 3c) was a superimposition of individual components of MGN and β-CD. An endothermic signal correspondent selleck compound to the fusion of MGN suffered displacement from 253.0 °C to 255.2 °C, and the fusion temperature of β-CD experimented a reduction from 335.0 °C to 271.4 °C. DSC curve of MGN:β-CD 1:1 complex (Fig. 3d) showed a broad endothermic peak between 80 °C and 100 °C corresponding to evaporation of water molecules absorbed on the lattice and/or inserted into β-CD cavities. DSC curves corresponding to pure β-CD, physical Farnesyltransferase mixture and MGN:β-CD complex had shown that the amount of water was minor after the MGN incorporation. For the complex MGN:β-CD was observed that fusion endothermic peak of the MGN almost

disappeared, however, a small endothermic peak was detected at 259.5 °C, which displacements confirmed that MGN was included into β-CD cavity. Fig. 4 shows the percentage of DPPH radical-scavenging activity (RSA-DPPH ) of the samples, in comparison with the GA control. Note that the MGN:β-CD 1:1 complex showed a higher antioxidant activity when compared with its free form, for MGN concentrations of 50 and 100 μmol L−1. As expected, GA was more effective. The highest MGN concentration of 500 μmol L−1 shows a RSA-DPPH (%) similar to the one obtained with GA (100 μmol L−1). MGN in complexed form is more reactive toward DPPH than its free form, except at higher concentration 500 μmol L−1. At this concentration, MGN is in excess in the medium consuming all DPPH.