Anthocyan-rich foods have attracted lots of attention because of their potential biological and pharmacological applications. Anthocyanins richly exist in blueberry fruits and have been proved to possess various bioactive properties. Despite the potential application of anthocyanins in the food, pharmaceutical and cosmetic industries, their use is limited because of their relative instability. Recently, much attention has been given to a particular family of anthocyanin derivatives, the pyranoanthocyanins that have been indicated to have higher stability than the original anthocyanins. However, the anti-cancer activity of pyranoanthocyanins is largely unknown. The objective of this study was to conduct a comparative analysis on the stability and anti-cancer activities of anthocyanins, anthocyanidins and pyranoanthocyanidins. Pyranoanthocyanidins exhibited the highest stability in the pH range 3.0–9.0, while anthocyanidins had the strongest inhibition on HeLa cells among the three anthocyan pigments. All the anthocyan pigments could effectively induce cell cycle arrest at the G₂/M phase in conjunction with a marked increase in the expression of the p53 protein. Exposure of HeLa cells to three anthocyan pigments caused pronounced late apoptosis that might be involved in the activation of the p38 MAPK/p53 signaling pathway. These findings suggest that anthocyanidins and pyranoanthocyanidins might be more promising anti-cancer agents than anthocyanins and warrant further evaluation regarding the molecular mechanisms.

Lysozyme is in high demand due to its many favorable characteristics such as being naturally occurring, non-toxic, and easy to digest and absorb. Recently, superparamagnetic nanoparticles with strong magnetic responsiveness have attracted significant interest for enzyme purification. The aptamer of the enzyme can be chemically synthesized rapidly at a large scale using simple and low-cost preparation methods. Therefore, Fe₃O₄ nanoparticles (Fe₃O₄ NPs) were prepared by chemical co-precipitation and were then functionalized with amino groups to produce NH₂-Fe₃O₄ NPs. The specific reaction of aldehyde and amino groups was used to attach lysozyme aptamers with specific sequences to NH₂-Fe₃O₄ NPs to produce Apt-NH₂-Fe₃O₄ NPs. The synthesized materials were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), hysteresis loop analysis, and thermogravimetric analysis (TGA). The optimal experimental conditions for adsorption of lysozyme were investigated. The effects of initial lysozyme concentration, adsorption time, pH, reaction temperature, and ionic strength were determined. The maximum adsorption capacity and relevant activity of Apt-NH₂-Fe₃O₄ NPs was 460 mg·g⁻¹ and 16,412 ± 55 U·mg⁻¹ in an aqueous lysozyme solution. In addition, as demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) electrophoresis analysis, lysozyme could be separated from crude fresh egg white using Apt-NH₂-Fe₃O₄ NPs with an amount up to 113 ± 4.2 mg·g⁻¹ and an activity up to 16,370 ± 46 U·mg⁻¹.