# Inhibition of Peroxidation Potential and Protein Oxidative Damage by Metal Mangifera Complexes
## 3 Results
### Preparative Chromatography of Metal-MF Complexes  
As per Table 1, compounds corresponding to Peaks 2 and 3 (ratio 1:2) for the reactions of Cu (II) and Zn (II) sulfates yielded 164 mg (Cu-1) and 186 mg (Cu-2), and 221 mg (Zn-1) and 234 mg (Zn-2), respectively, of yellowish crystalline powders with m.p. \(>\) 300 \({}^{\circ}\)C decomposed after preparative column chromatography. The compound corresponding to  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Sample**} & \multicolumn{2}{c}{**Peak 1**} & \multicolumn{2}{c}{**Peak 2**} & \multicolumn{2}{c}{**Peak 3**} & \multicolumn{2}{c}{**Peak 4**} \\ \cline{2-9}  & **RT (min)** & \([\mathrm{M}-\mathrm{H}]^{-}\) & **RT (min)** & \([\mathrm{M}-\mathrm{H}]^{-}\) & **RT (min)** & \([\mathrm{M}-\mathrm{H}]^{-}\) & **RT (min)** & \([\mathrm{M}-\mathrm{H}]^{-}\) \\ \hline MF & 17.8 \(\pm\) 0.2 & 421 & - & - & - & - & - & - \\ \hline Cu (1:2) & 17.6 \(\pm\) 0.2 & 421 & 25.8 \(\pm\) 0.4 & 905 & 27.5 \(\pm\) 0.4 & 903 & - & - \\ \hline Zn (1:2) & 17.8 \(\pm\) 0.3 & 421 & 26.2 \(\pm\) 0.2 & 907 & 28.8 \(\pm\) 0.4 & 905 & - & - \\ \hline Zn (1:3) & 17.4 \(\pm\) 0.4 & 421 & 26.4 \(\pm\) 0.3 & 907 & 28.6 \(\pm\) 0.4 & 905 & 41.4 \(\pm\) 0.6 & 1388 \\ \hline Se (1:2) & 17.6 \(\pm\) 0.4 & 421 & - & - & 33.5 \(\pm\) 0.5 & 934 & - & - \\ \hline Se (1:3) & 18.0 \(\pm\) 0.4 & 421 & - & - & 33.3 \(\pm\) 0.5 & 934 & 44.5 \(\pm\) 0.5 & 1447 \\ \hline \hline \end{tabular} Legend: Sample describes the salt metal ion and the number between brackets mean stoichiometric ratio metal salt:mangiferin for the reaction; RT: retention time; \([\mathrm{M}-\mathrm{H}]^{-}\): molecular ion in negative mode mass spectrometry (\(m/z\)); MF: mangiferin.  
\end{table}
Table 1: Chromatographic retention times and molecular ions \([\mathrm{M}-\mathrm{H}]^{-}\) of mangiferin and metal-mangiferin complexes by HPLC-ESI-MS.  
peak 3 (Se-1) for the reaction of sodium selenite with MF (ratio 1:2) yielded 338 mg of a yellowish crystalline powder with m.p > 300 \({}^{\circ}\)C decomposed. Compounds corresponding to Peaks 2, 3, and 4 for the reaction of Zn (II) sulfate with MF (ratio 1:3) yielded 110 mg (Zn-3), 105 mg (Zn-4), and 198 mg (Zn-5), respectively. Compounds corresponding to Peaks 3 and 4 for the reaction of sodium selenite with MF (ratio 1:3) yielded 248 mg (Se-2) and 367 mg (Se-3), respectively, of crystalline or amorphous yellowish powders, respectively, with m.p. >300 \({}^{\circ}\)C decomposed. The purities of all compounds (10) were assessed by HPLC-DAD (>90% purity) with non-reacted MF as the main impurity (Peak 1 in all chromatograms). UV spectra for all metal-MF complexes showed the four characteristic absorption maxima of MF (\(\lambda_{\rm max}=240\), 255, 320, and 365 nm) but no significant differences were observed regarded to MF as reference.  
Figure 1: (**A**). Isotopic peak cluster of Cu (II)–MF complex \(\rm[M-H]^{-}\) ion, Peak 2. (**B**). Isotopic peak cluster of Zn (II)–MF complex \(\rm[M-H]^{-}\) ion, Peak 3. (**C**). Isotopic peak cluster of Se (IV)–MF complex \(\rm[M-H]^{-}\) ion, Peak 4.