An eco‐friendly extraction and purification method of nuciferine from Folium nelumbinis with p‐sulfonatocalix[6]arenes.

Introduction: Folium nelumbinis is used as vegetable, functional food and herbal medicine in Asia. p‐Sulfonatocalix[6]arene (SC6A) is a water‐soluble supramolecular macrocycle and has never been applied to the extraction of herbal products. Objective: In this study, SC6A‐assisted extraction of nuciferine from Folium nelumbinis has been carried out to develop an eco‐friendly extraction process with high extraction efficacy and easy operation. Methods: Single‐factor experiments were adopted to obtain the optimal conditions for the SC6A‐assisted extraction of nuciferine from Folium nelumbinis, and then nuciferine and SC6A were separated easily by one‐step alkalization. The host–guest complexes between nuciferine and SC6A were analyzed by competitive fluorescence titration, DSC, FT‐IR and 1H‐NMR. Results: The optimal SC6A/Folium nelumbinis/solution ratio for extraction was 0.4:1:20 (g/g/mL), with a granulometric fraction below 180 μm and an extraction time of 1 h with soaking. The purity and recovery of nuciferine extracted with SC6A were increased 29.24 and 35.73 times compared with extraction with aqueous solution, respectively. Moreover, a good reusability of SC6A in the extraction of nuciferine was demonstrated. Competitive fluorescence titration, DSC, FT‐IR and 1H‐NMR characterization indicated that SC6A could form host–guest complexes with nuciferine at a ratio of 1:1. Conclusion: The study provided an eco‐friendly, safe and effective nuciferine extraction method, which can be used for the development of nutrition supplements containing nuciferine. SC6A‐assisted extraction of nuciferine from Folium nelumbinis has been carried out to develop an eco‐friendly, safe and effective nuciferine extraction method. The host‐guest complexes between nuciferine and SC6A were analyzed by competitive fluorescence titration, DSC, FT‐IR and 1H‐NMR. A good reusability of SC6A in the extraction of nuciferine was demonstrated. [ABSTRACT FROM AUTHOR]