Development of molecular imprinted cryogel membranes for purification of naringenin

The antioxidant potential of naringenin has been confirmed in various animal models and cell line studies. The main effects of Naringenin include xanthine oxidase, nicotinamide adenine dinucleotide phosphate oxidase, lipoxygenase and inhibition of pro-oxidant enzymes such as cyclooxygenase, metal ion chelation and, most importantly, scavenging of free radicals. In addition, Naringenin increases the physiological level of various antioxidant enzymes such as glutathione peroxidase, superoxide dismutase and catalase. It is also known to reduce protein nitration and oxidation facilitated by peroxynitrite. In this research, molecularly imprinted cryogel membranes (MIMs) were constructed for the selective separation of naringenin from the natural media. Nonimprinted membranes (NIMs) were also prepared without naringenin to compare specifity of prepared imprinted membranes. MIMs were subjected to some characterization analyses e.g., contact angle measurement, swelling tests, attenuated total reflection-fourier transform infrared spectroscopy (ATR-FTIR) and Scanning electron microscope (SEM). Selectivity studies of MIMs were carried out both in aqueous media and natural orange juice. In selectivity studies, gallic and caffeic acid molecules were used as competitor agents due to their structural similarity to naringen. Some results obtained as follows: Contact angle values for MIMs and NIMs were found to be 58.5º and 71.8º, respectively. The maximum adsorption capacities of MIMs and NIMs for naringenin were found to be 66.5 and 14 mg/g, respectively at an initial concentration of 2 mg/mL. The qmax and Kd values of the high-affinity binding sites of the obtained Scatchard plot were found to be 0.126 mmol/g (34.4 mg/g) and 0.16 mM (1.6.10-4 M), respectively. The selectivity of MIMs for naringenin was found 1.99 and 2.26 times high when compared to gallic and caffeic acids, respectively. The adsorption of naringenin from natural orange juice with MIMs was found to be 843 µg/g.