The complex (1:1) was obtained by co-evaporation. MGN and β-CD, in an equimolar ratio (1:1) were added to an aqueous solution prepared with 5 mL ethanol/100 mL water. The solution was protected from light and mechanically shaken at 170 rpm at 25 °C in a Marconi MA-420 incubator shaker (São Paulo, Brazil) for 24 h. After evaporation of the ethanol from the reaction mixture, the uncomplexed MGN was removed by filtration. Then,

INK 128 cell line water was evaporated under reduced pressure in a Büchi Rotavapor (Büchi, Germany) and dried in vacuum, giving the MGN:β-CD complex. The FT-IR spectra of MGN, β-CD and MGN:β-CD complex were recorded at room temperature in a spectral region between 4000 and 500 cm−1 on an IRPrestige-21, Fourier Transform Spectrometer (Shimadzu, Kyoto, Japan). Samples were prepared as small pellets by mixing each of them in a mortar with KBr (1:100) and then pressed. A blank KBr disc was used as a background. DSC analysis was carried out for MGN, β-CD and the complex with a DSC-60 calorimeter (range 25–500 °C) (Shimadzu, Kyoto, Japan). The temperature scale Inhibitor Library in vitro was calibrated using α-alumina powder. Samples (5.0–10.0 mg) were

placed in standard aluminum pans and measurements were performed at a heating rate of 5 °C min−1 from 25 to 400 °C in a dynamic nitrogen atmosphere (flow rate = 20 mL/min). The MGN and MGN:β-CD complex were prepared with 5 mL ethanol/100 mL water. The solution of the MGN:β-CD (1:1) complex was prepared at concentrations of 50, 100 and 500 μmol L−1. The solutions were stirred (170 rpm) for 24 h at 25 °C. Initially, a concentration of 100 μmol L−1 for the solution of DPPH in only methanol was used. In order to analyze solvent effects, the concentrations of 100 μmol L−1 for MGN and 50 μmol L−1 for DPPH were used. The antioxidant activities of MGN, β-CD, MGN:β-CD complex samples and GA (positive control) were measured in terms of their radical scavenging ability (RSA), using the DPPH method. ID-8 MGN,

β-CD or MGN:β-CD complex solutions (0.30 mL) were mixed with 2.7 mL of 50 μmol L−1 DPPH solution in different proportions of methanol:water and ethanol:water (20:80, 30:70, 50:50 and 100:0 mL:mL) in a 3 mL-quartz cuvette. The DPPH absorption values were obtained at 516 nm every 5 min, during 50 min by UV–vis spectrophotometer (MultiSpec-1501, Shimadzu, Japan). The results are expressed as remaining DPPH R (%) as a function of time (Oliveira et al., 2009). All measurements were performed in triplicate. The MGN, β-CD and MGN:β-CD (1:1) complex aqueous solutions were prepared with 5 mL ethanol/100 mL water at a concentration of 100 μmol L−1. The solution was stirred (170 rpm) for 24 h in the absence of light. The ORAC analyses were carried out on a Synergy HT multidetection microplate reader, from Bio-Tek Instruments, Inc. (Winooski, USA), using 96-well polystyrene white microplates, purchased from Nunc (Denmark).