Synthesis of Smart Food Packaging from Poly (Gelatin-co-Dimethyl Acrylamide) / Citric Acid-Red Apple peel Extract

ABSTRACT

A novel and smart hydrogel was synthesized from N, N dimethyl acrylamide (DMAAm), gelatin, and citric acid (CA) red apple peel extract (RApE) to be utilized as a multi-functional food packaging material. The p(Gelatin-co-DMAAm)/CA-RApE was prepared through a redox polymerization technique in film form in petri dishes. Mechanical and water resistance of the p(Gelatin-co-DMAAm)/CA-RApE was improved by the addition of citric acid and N, N, methylenebisacrylamide (MBA) as cross linker. The characterization of p(Gelatin-co-DMAAm)/CA-RApE was carried out by Fourier transform infrared spectroscopy (FT-IR), thermo gravimetric analyzer (TGA), scanning electron microscopy (SEM), and dynamic and mechanical analyzer (DMA). FT-IR revealed the existence of bonding interactions between the functional group of RApE and gelatin, carbonyl groups of DMAAm, and carboxylic acid groups of CA. TGA results found that p(Gelatin-co-DMAAm)/CA-RApE was stable up to 565°C. It was observed that RApE improved thermal stability and decreased the elasticity of the p(Gelatin-co-DMAAm)/CA-RApE. When tested against Escherichia coli, Bacillus subtilis and Staphylococcus aureus, p(Gelatin-co-DMAAm)/CA-RApE was observed to have antimicrobial activity. Total antioxidant and anthocyanin effect of p(Gelatin-co-DMAAm)/CA-RApE was analyzed. Additionally, to monitor the color changes of p(Gelatin-co-DMAAm)/CA-RApE, it was studied at different pH values. Furthermore, p(Gelatin-co-DMAAm)/CA-RApE was applied to real samples such as whole pasteurized milk and cheese. It was found to have a good color indicator and antimicrobial activity for pasteurized whole milk and cheese. It was concluded that p(Gelatin-co-DMAAm)/CA-RApE is a very good candidate to be used in food packaging and biomedical materials, along with other potential applications.     

Modeling and predicting binding affinity of phencyclidine‐like compounds using machine learning methods

Machine learning methods have always been promising in the science and engineering fields, and the use of these methods in chemistry and drug design has advanced especially since the 1990s. In this study, molecular electrostatic potential (MEP) surfaces of phencyclidine‐like (PCP‐like) compounds are modeled and visualized in order to extract features that are useful in predicting binding affinities. In modeling, the Cartesian coordinates of MEP surface points are mapped onto a spherical self‐organizing map (SSOM). The resulting maps are visualized using electrostatic potential (ESP) values. These values also provide features for a prediction system. Support vector machines and partial least‐squares method are used for predicting binding affinities of compounds. Copyright © 2009 John Wiley & Sons, Ltd.     

Biological activities,phenolic profiles and essential oil components of Tanacetum cilicicum (BOISS.) GRIERSON

Tanacetum species are consumed as tea in Turkey. We comparatively evaluated the phytochemical potentials and antioxidant activities of the essential oil and methanolic extracts of Tanacetum cilicicum. The chemical constitutes of T. cilicicum essential oil and antioxidant activity of this species was analysed by gas chromatography–mass spectrometry (GC–MS) method. Bicyclo (3,1,1) hept-2-en-4-ol (21.92%), camphor (15.56%) and 1,8-cineole (13.45%) which are oxygenated monoterpenes were found as the major constituents. Phenolic acids and flavonoids were quantificated by HPLC–UV. Catechin was found as the main component. The essential oils and methanolic extracts were evaluated by antioxidant activities. The leaves exhibited significant metal chelation activity with a value of 20.75 ± 4.63 μg/mL.     

Compressed images for affinity prediction (CIFAP): a study on predicting binding affinities for checkpoint kinase 1 protein inhibitors

Analyses of known protein–ligand interactions play an important role in designing novel and efficient drugs, contributing to drug discovery and development. Recently, machine learning methods have proven useful in the design of novel drugs, which utilize intelligent techniques to predict the outcome of unknown protein–ligand interactions by learning from the physical and geometrical properties of known protein–ligand interactions. The aim of this study is to work through a specific example of a novel computational method, namely compressed images for affinity prediction (CIFAP), in which binding affinities for structurally related ligands in complexes with human checkpoint kinase 1 (CHK1) are predicted. The CIFAP algorithm presented here relates published pIC ₅₀ values of 57 compounds, derived from a thienopyridine pharmacophore, in complexes with CHK1 to their two‐dimensional (2D) electrostatic potential images compressed in orthogonal dimensions. Patterns obtained from the 2D images are then used as inputs in regression and learning algorithms such as support vector regression (SVR) and adaptive neuro‐fuzzy inference system (ANFIS) methods to validate the experimental pIC ₅₀ values. This study revealed that the 2D image pixels in the vicinity of bound ligand surfaces provide more relevant information to make correlations with the empirical pIC ₅₀ values. As compared with ANFIS, SVR gave rise to the lowest root mean square errors and the greatest correlations, suggesting that SVR could be a plausible choice of machine learning methods in predicting binding affinities by CIFAP. Copyright © 2013 John Wiley & Sons, Ltd.     

X-ray diffraction, spectroscopic and DFT studies of 1-(4-bromophenyl)-3,5-diphenylformazan

The crystal structure of 1-(4-bromophenyl)-3,5-diphenylformazan was determined by X-ray single crystal diffraction technique. The crystals are orthorhombic, a = 23.0788(9), b = 7.9606(3), c = 18.6340(12) Å, Z = 8, sp. gr. Pbca, R ₁ = 0.074. The structure was also examined using the density-functional theory. Its structure stability, and frontier molecular orbital components were discussed and the results were compared with X-ray and spectral results. The maximum absorbtion peaks of the UV-vis spectrum of the compound have been calculated using the time-dependent density-functional theory. It was found a good agreement between the calculated and experimental maximum absorption wavelength.     

Experimental (13C NMR, 1H NMR, FT-IR, single-crystal X-ray diffraction) and DFT studies on 3,4-bis(isoproylamino)cyclobut-3-ene-1,2-dione

In this work, 3,4-bis(isoproylamino)cyclobut-3-ene-1,2-dione C(10)H(16)N(2)O(2) (I), was synthesized and characterized by (13)C NMR, (1)H NMR, FT-IR, UV-vis spectroscopy and single-crystal X-ray diffraction. DFT method with 6-31G(d,p) basis set has been used to calculate the optimized geometrical parameters, atomic charges, vibrational frequencies and chemical shift values. The calculated vibrational frequencies and chemical shift values are compared with experimental FT-IR and NMR spectra. The results of the calculation shows good agreement between experimental and calculated values of the compound I. The existence of N-H?O type intermolecular ve C-H?O type intramolecular hydrogen bonds can be deduced from differences between experimental and calculated results of FT-IR and NMR. In addition, the molecular electrostatic potential map and frontier molecular orbitals and electronic absorption spectra were performed at B3LYP/6-31G(d,p) level of theory. HOMO-LUMO electronic transition of 4.90 eV are derived from the contribution of the bands π→π* and n→π* The spectral results obtained from FT-IR, NMR and X-ray of I revealed that the compound I is in predominantly enamine tautomeric form, which was supported by DFT calculations.     

Trialkylsulfonium dicyanamides--a new family of ionic liquids with very low viscosities

Trialkylsulfonium dicyanamides show surprisingly low viscosities down to -20 degrees C and are therefore highly interesting liquid materials for separation processes and electrolyte applications at low temperatures.     

Comparing the effect of sub-critical water extraction with conventional extraction methods on the chemical composition of Lavandula stoechas

The volatile extract composition of Lavandula stoechas flowers obtained by hydrodistillation (HD), subcrtical water extraction (SbCWE) and organic solvent extraction under ultrasonic irradiation (USE) were estimated by gas chromatography-mass spectrometry (GC-MS). One hundred and twenty four components were detected in SbCWE extracts while 94 and 65 signals were gained from HD and USE extracts, respectively. Most of the constituents were identified. The major compounds in all three extracts were fenchon, camphor, myrtenyl acetate, myrtenol and 1,8-cineol, but they differ in quantitatively. The total monoterpene hydrocarbons are higher in HD and USE extracts than those of SbCWE extract. However, SbCWE extract had higher concentration of light oxygenated compounds which contributes to the fragrance of the oil in a major extension. Heavy-oxygenated compounds was also in higher abundance in SbCWE extract (9.90%) than those of HD and USE extracts (3.19 and 4.78%, respectively). Effect of temperature on the extraction yield of SbCWE was investigated and while oil yield was increasing with an increase in temperature, a decrease in the extraction ability of sub-critical water toward the more polar compounds such as, 1,8-cineol, camphor and fenchon, was observed. Kinetic studies shown that SbCWE is clearly quicker than conventional alternatives. Most of components of volatile compounds were extracted at 15min.     

5-Methyl-4-[3-(2-oxopyrrolidin-1-yl)propyl]-2,4-dihydro-3H-1,2,4-triazol-3-one: Synthesis,Characterization, and DFT Study

Russian Journal of Organic Chemistry - 5-Methyl-4-(3-(2-oxopyrrolidin-1-yl)propyl)-2,4-dihydro-3H-1,2,4-triazol-3-one was synthesized and characterized by X-ray, FTIR and NMR spectroscopic...     

2-Propylamino-5-[4-(2-hydroxy-3,5-dichlorobenzylideneamino) phenyl]-1,3,4-thiadiazole: X-ray and DFT-calculated structures

2-Propylamino-5-[4-(2-hydroxy-3,5-dichlorobenzylideneamino) phenyl]-1,3,4-thiadiazole, formulated as C₁₈H₁₆Cl₂N₄OS (I), was synthesized. The crystal and molecular structure of (I) have been determined by ¹H-NMR, IR, and X-ray single crystal diffraction. The compound (I) crystallizes in the monoclinic, space group P2(1)/c with unit cell parameters a = 9.0576(2) Å, b = 24.3382(8) Å, c = 9.0585(2) Å, M _r = 407.31, V = 1851.13(9) Å³, Z = 4, R ₁ = 0.036, and wR ₂ = 0.096. Molecular geometry from X-ray experiment of (I) in the ground state has been compared using the density functional method (B3LYP) with 6-31G(d) basis set. To determine conformational flexibility, molecular energy profile of (I) was obtained by semi-empirical (PM3) calculations with respect to selected degree of torsional freedom, which was varied from ?180° to +180° in steps of 10°. The results are indicative that the Schiff base, which contains a thiadiazole ring, prefers to be in E-configuration. In addition, molecular electrostatic potential, frontier molecular orbitals, and natural bond orbitals analysis were performed by the B3LYP/6-31G(d) method.