Development of casein-based nanoencapsulation systems for delivery of epigallocatechin gallate and folic acid.

In this work, binding characteristics of two hydrophilic nutraceutical models, namely epigallocatechin gallate (EGCG) and folic acid (FA), to sodium caseinate were studied by fluorimetry technique. EGCG-loaded casein molecules were then converted to either re-combined casein micelles (r-CMs) or casein nanoparticles (CNPs). Binding stoichiometry of EGCG and FA was 0.81 and 1.02, respectively. As determined by DLS technique, the average particle size of r-CMs prepared at 0.5% concentration was 66.2 nm. Thermal treatment (74°C, 20 s) had significant (p < 0.05) influence on the particle size of nanocarriers, but not nutraceutical loading. The average size of CNPs was larger than that of r-CMs. The encapsulation efficiency (EE) of EGCG was 85%, and its ejection from the nanocarrier was less than 3% over 21 days. Alkaline conditions resulted in higher release of EGCG than acidic conditions. r-CMs were more effective than CNPs during the protection of EGCG against heat-induced degradation. TEM micrographs confirmed the formation of r-CMs.

Vibrational spectra, normal coordinate analysis, and hydrogen bond investigation of pyridinium perchlorate.

The IR and Raman spectra of pyridine perchlorate salt (PyHClO4) have been recorded in the 4000-300 and 3200-200cm-1 regions, respectively. The structure and vibrational spectra of pyridine salt have been investigated by means of ab initio and density functional theory (DFT) calculations. To examine the efficiency of basis sets in predicting the vibrational spectra of ClO4-1 ion, several basis sets were used with the B3LYP and B2PLYP levels of theory. It was shown that the 6-311(3df) basis set gives reasonably vibrational wavenumbers for simulation of perchlorate ion experimental vibrational wavenumbers. Therefore, the B3LYP/6-311G(3df) level was used to calculate the vibrational spectra of pyridine perchlorate salt in CH3CN solution. For comparison, the vibrational wavenumbers were also calculated at the B3LYP/aug-cc-pVTZ level. The geometry of PyHClO4 was calculated in the gas phase as well as in solutions, using SCRF-PCM method. According to these calculations, the structure and hydrogen bonding in PyHClO4 is highly affected by media. Two hydrogen bonding systems between ClO4-1 and pyridinium ions were recognized. The nature of these hydrogen bonds is theoretically investigated by using atoms in molecule (AIM) method and natural bond orbital (NBO) analysis. A normal coordinate analysis was performed by using the internal coordinates calculated at the B3LYP/6-311G(3df,p) level for the vibrational normal modes of the titled compound.

Efficient delivery of quercetin after binding to beta-lactoglobulin followed by formation soft-condensed core-shell nanostructures.

Nature-made inherent transporting property of beta-lactoglobulin (BLG) was exploited to develop delivery systems for quercetin. After binding to BLG, quercetin was nanoencapsulated within soft-condensed nanostructures of BLG and sodium alginate (ALG). Fluorimetry results revealed that quercetin could bind to BLG even at acidic conditions. The amounts of stoichiometry binding (n) were 1.24 and 1.62 at pH values of 4 and 7, respectively. Formation of core-shell type nanostructures was confirmed by transmission electron microscopy. Quercetin was efficiently entrapped (>93%). The ejection from the carrier was very limited over time (<1% during 1month). The protection of nanoencapsulated quercetin was at least 3 times better than that of free quercetin. Quercetin was not released (<3.5% during 6h) in simulated gastric fluids (pH 1.2 and 4); while, a sustained release (77% during 12h) was observed in simulated intestinal fluid (pH 7.4).

Vibrational assignment and structure of trifluorobenzoylacetone. A density functional theoretical study.

Molecular structure and vibrational frequencies of 4,4,4-trifluoro-1-phenyl-1,3-butanedione, known as trifluorobenzoylacetone (TFBA), have been investigated by means of density functional theory (DFT) calculations. The results were compared with those of benzoylacetone (BA), acetylacetone (AA), and trifluoroacetylacetone (TFAA). Comparing the calculated and experimental band frequencies and intensities suggests coexisting of both stable cis-enol conformers in comparable proportions in the sample. The energy difference between the two stable chelated enol forms is negligible, 0.96 kcal/mol, calculated at B3LYP/6-311++G** level of theory. The molecular stability and the hydrogen bond strength were investigated by applying the natural bond orbital (NBO) theory and geometry calculations. The theoretical calculations and spectroscopic results indicate that the hydrogen bond strength of TFBA is between those of TFAA and AA, considerably weaker than that of BA.