Explore the Interaction between Ellagic Acid and Zein Using Multi-Spectroscopy Analysis and Molecular Docking

Abstract

With the increasing interest in value-added maize products, the interaction of zein with bioactive molecules to become more nutritional and beneficial to human health has gained a lot of attention. To broaden the application of ellagic acid (EA) in maize flour products, we investigated the interaction between zein and EA. The fluorescence quenching type of zein interacting with EA was mainly static quenching through hydrophobic interaction, as demonstrated by quenching behavior modeling, and ultraviolet-visible spectroscopy confirmed the formation of zein–EA complexes. Synchronous fluorescence spectroscopy showed that EA reduced the polarity of zein around tyrosine residues, which were exposed to a more hydrophobic microenvironment. Meanwhile, circular dichroism suggested that EA noticeably changed the secondary structure of zein, which was mainly reflected in the increase of α-helix and β-sheet content and the decrease of random coil content. Finally, the molecular docking simulation found that zein could have five active sites binding to EA and there was hydrogen bond interaction besides hydrophobic interaction. The findings of this study provided a basis for a theory for the interaction mechanism between zein and EA, which could be essential for developing value-added plant-derived protein products using EA as a functional component.

Preparation and Investigation of Thermally Annealed Zein–Propolis Electrospun Nanofibers for Biomedical Applications

“…In general, studies are performed with propolis hydroalcoholic extracts and many isolated compounds from propolis are also studied, however, one should take into account that many propolis researchers agree that its constituents act in synergy, and once separated, they may even lose their activity. [ 29–61 ] Thinking about the healing activity, which is one of the main objectives to be achieved when developing nanofibers, the sum of antioxidant, antibacterial, and anti‐inflammatory activities generated by the combination of polar and apolar propolis constituents is essential for an organized repair and this significantly increases the deposition of extracellular matrix components, reduces the migration of inflammatory cells, and promotes tissue revascularization during the healing phases. [ 18–63 ]…”

“…[ 29–61 ] Thinking about the healing activity, which is one of the main objectives to be achieved when developing nanofibers, the sum of antioxidant, antibacterial, and anti‐inflammatory activities generated by the combination of polar and apolar propolis constituents is essential for an organized repair and this significantly increases the deposition of extracellular matrix components, reduces the migration of inflammatory cells, and promotes tissue revascularization during the healing phases. [ 18–63 ]…”

“…All fibers presented a ribbon‐like shape, as observed by scanning electron microscopy (SEM) images (Figure 4 and Figure S4, Supporting Information), characteristic of zein electrospun fibers obtained from ethanolic solutions. [ 20–77 ] It is interesting to note that occasionally, the opposite fiber boundaries collapse, causing fibers to have narrowing points. This phenomenon has been also observed by other groups and may occur due to ethanol rapid evaporation.…”

“…[ 28,29 ] It was demonstrated that zein and propolis form a perfect match due to the hydrophobic properties of both materials. [ 42,43 ] The biocompatibility and delivery of propolis were successfully tested in vitro using murine fibroblast and the interaction of nanofibers and cells was observed for the first time. Therefore, the production of zein nanofibers containing propolis is extremely advantageous since its antioxidant, wound healing, and antibacterial activity included in a perfect framework may facilitate cellular anchorage, and can thus be used in dressing or tissue regeneration devices.…”

“…Therefore, the production of zein nanofibers containing propolis is extremely advantageous since its antioxidant, wound healing, and antibacterial activity included in a perfect framework may facilitate cellular anchorage, and can thus be used in dressing or tissue regeneration devices. [ 18–45 ]…”