Nano-ovalbumin: a green biocatalyst for biomimetic synthesis of tetrahydrodipyrazolo pyridines in water

In this investigation, a simple and new protocol was used to prepare large quantities of purified nano-ovalbumin from egg white. Nano-ovalbumin, as a retrievable and metal-free biocatalyst, was characterized by FT-IR, FESEM, XRD, MALDI-TOF and TGA/DTA. This biocatalyst displayed a high activity for green and efficient synthesis of tetrahydrodipyrazolo pyridines via multi-component reaction of ethyl acetoacetate, hydrazine, aldehyde and ammonium acetate in water. This new bio-catalyzed process could serve as a valuable synthetic alternative for such multi-component reactions in terms of economic aspects and biocompatibility of conditions. Graphical abstract