Zein Conjugates with Potential Controlled Drug Delivery Properties
Faculty of Chemistry, Alexandru Ioan Cuza University of Iasi
Zein proteins belong to the class of prolamin proteins which, in maize, represent more than 60% of the total endosperm protein. Based on their molecular weight, sequence and solubility, zeins are classified into four different zein structures (α, β, γ, δ). Moreover, the most defining characteristic of zein proteins refers to their insolubility in water and their high solubility in aqueous high percentage alcoholic solutions, such as 65% ethanol to 95% ethanol. In addition, zeins extracted from maize flours have wide application in: (i) refining food products, such as candies and nuts; (ii) microspheres filled with pesticides are produced out of zein proteins for controlled release of the biologically active substances to provide a safer working environment; (iii) “zein films” are used as a controlled release matrix of active components, such as salicylic acid, lysozyme and EDTA; (iv) coating of tablets and in zein-coated chitosan /tripolyphosphate nanoparticles for oral delivery of selenite. We report here on an original and novel process, which consists in successive grinding and sieving of corn seeds to bring about different maize flours, with chemical compositions and protein contents depending on particle hardness. We have also investigated zein extraction using 65-95% aqueous ethanol under ultrasound conditions from dry-ground whole corn as well as meals with different grain sizes. Besides, the extracted zein and the commercial zein protein were used for different conjugates synthesis. Protein determination was made by UV-Vis spectrophotometry. We have applied modern methods such as MALDI ToF mass spectrometry and FT-IR spectroscopy to characterize the synthesized zein conjugates.
„This work was supported by a grant of the Ministry of Research, Innovation and Digitization, CNCS/CCCDI – UEFISCDI, project number PN-III-P1-1.1-PD-2019-0442, within PNCDI III”.
Keywords: zein, extraction, conjugates, mass spectrometry, fourier transformed infrared spectroscopy.