Calein. Diamagnetic metal ions and Zn2 Ga3 were used as probes for Fe2 and Fe3, respectively used as the iron complexes not detectable by NMR. All studies were performed in an L Solvents conducted 50/50 DMSO TrisHCl d6/D2O. 1H NMR assignments for advanced baicalein were reported on by Lim and colleagues. GSK461364 The 1H NMR spectra of the titration of 5 mM Zn2 with baicalein was shown. 5th Were not included as Zn2 Changes observed for most of the peaks baicalein, but the H8 protons experienced a large e Ver Change by downfield. The summit of protons H3 also slightly downfield. to 1 molar equivalent. Zn2 added, a precipitate thus lower Signalintensit Was observed t. Ver these Change indicates that the NMR binding site in the N eh The metal proton H8, i. E. O6 O7 website and cycle A.
This binding site was best performed by Similar experiments with baicalin, the gel Nde O7 has blocked by a glucose unit CONFIRMS. No ENMD-2076 Ver Change was observed by NMR after addition of Zn2 In baicalin and best Firmed that the website is authentic O7 for Zn2 essential. Titration with Ga3 baicalein showed anything similar 1H-NMR chemical shifts relative to those with Zn2, i observed. s H3 was a slight shift to lower field, w during H8 was a big e Ver downfield change, suggesting that Ga3 binds the same site as Zn2. However, since several Ga3 added appeared new NMR peaks,. The formation of several species No attempt was made to identify these species. Proof of our NMR investigations k Can we eventually found that the metal between the hydroxyl carbons 6 and 7 in complex baicalein Zn or Ga.
Because of Hnlichen properties coordination of Fe2 and Zn2 and Fe3 and Ga3, and under into account the results of studies on MS UV / Vis and ESI, it can suggested that both Fe2 and Fe3 bind baicalein on the same gel nde Zn2or Ga3 as do i. e, O6 and O7 site on the ring A. Figure 7 shows the proposed structure for the species Fe2 baicalein. The inhibition of the Fenton chemistry baicalein and baicalin deoxyribose degradation by two tests were conducted to determine the capability F Baicalin and baicalein, the formation of hydroxyl radicals by the Fenton reaction found Promotes inhibit evaluated. 8A shows the absorbance at 532 nm of the complex TBA malonaldehyde dependence Dependence.
On the concentration in the absence of Fe2 flavones, in the presence of 10 M baicalin, baicalein and 10 million It is clear that baicalein can completely Constantly inhibit Fenton-induced radicals caused Sch The even at concentrations up to 20 h at M. Fe2 Heren concentrations up to 50 M Fe2, curve slightly increased, but the inhibition is always still important. Under the same conditions can baicalin partially protect the deoxyribose molecule two Fenton Sch The by free radicals. As of the NMR study, baicalin not bind iron showed strong protection against radicals is probably part baicalin its free-radical singer-activity t. Kl to the mechanism by which baicalein Fenton-induced radicals Sch To inhibit i can Ren. e whether chelation or free-radical singer, Fe2 EDTA was used to rdern Fenton chemistry to f. Since EDTA can have a binding constant of iron by several Gr Enordnungen hours ago Than that of baicalein as baicalein-radical singer act in the Fe EDTA. 8B s