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The greater transparency of the polymer obtained by adding a small amount of molecular iodine to the liquid photopolymerizing composition is satisfactorily explained by the formation of a π,σ-type charge transfer (CT) complex of oligocarbonate dimethacrylate with molecular iodine. The CT band at 360 nm absorbs a significant part of the actinic radiation such that the rate of the photolytic decomposition of the photoinitiator in the initial polymerization stage permits release of free volume from the polymer into the liquid part of the photopolymerizing composite. Layer-by-layer photopolymerization occurs at advanced stages due to the thin upper layers exposed to UV irradiation becoming steadily more transparent. [ABSTRACT FROM AUTHOR]

Bis(trifluorobenzoylacetonato) copper(II), Cu(tfba)2, was assayed for isomerism, molecular structure, spectroscopic analysis, and complete vibrational assignment using calculated results from Density Functional Theory (DFT), Natural Bond Orbital (NBO), Atoms-In-Molecules (AIM) analysis at the B3LYP level with 6-311G(d) basis set, and experimental results were obtained via observed vibrational and UV–Vis spectra. To investigate the effects of methyl groups substitution by CF3 on the structure and metal–ligand bond strength of the titled molecules, the structure and vibrational spectra of Cu(tfba)2 were compared with those of bis(benzoylacetonato) copper (II), Cu(bzac)2 using the aforementioned calculation and experimental techniques. Additionally, the calculated values were compared to reported X-ray results. The theoretical and experimental spectroscopic results showed no significant difference between the Cu–O bond strength of Cu(tfba)2 and Cu(bzac)2. In addition, the results of antibacterial activities show that both complexes could be considered potential antibacterial candidates, but Cu(tfba)2 has slightly more antibacterial activity than Cu(bzac)2. Molecular docking studies also indicate that both complexes interact with DNA spontaneously via a minor groove. [ABSTRACT FROM AUTHOR]

Food additives are utilized in countless food products available for sale. They enhance or obtain a specific flavor, extend the storage time, or obtain a desired texture. This paper presents an automatic classification system for five food additives based on their absorbance in the ultraviolet domain. Solutions with different concentrations were created by dissolving a measured additive mass into distilled water. The analyzed samples were either simple (one additive solution) or mixed (two additive solutions). The substances presented absorbance peaks between 190 nm and 360 nm. Each substance presents a certain number of absorbance peaks at specific wavelengths (e.g., acesulfame potassium presents an absorbance peak at 226 nm, whereas the peak associated with potassium sorbate is at 254 nm). Therefore, each additive has a distinctive spectrum that can be used for classification. The sample classification was performed using deep learning techniques. The samples were associated with numerical labels and divided into three datasets (training, validation, and testing). The best classification results were obtained using CNN (convolutional neural network) models. The classification of the 404 spectra with a CNN model with three convolutional layers obtained a mean testing accuracy of 92.38% ± 1.48%, whereas the mean validation accuracy was 93.43% ± 2.01%. [ABSTRACT FROM AUTHOR]

To prepare molecularly imprinted polymers (MIPs) with specific selectivity for steranes, the prepolyme-rization system was screened by UV spectroscopy to determine the type, proportion and mode of action of functional monomers. In this study, the interaction intensities between three template molecules (cholesterol, β-sitosterol, deoxycholic acid) and four functional monomers (acrylic acid (AA), methacrylic acid (MAA), methyl methacrylate (MMA), and acrylamide (AM)) are compared respectively. The results show that the functional monomer AA can interact strongly with the three template molecules and form a stable prepolymerization system, so AA is selected as the functional monomer of MIPs. In addition, the UV spectral absorbance change and differential UV spectral analysis of different proportions of AA show that the optimal concentration ratios of the three template molecules to functional monomer AA are all 1:4, and the stable complex configurations formed are cholesterol-1AA, β-sitosterol-1AA and deoxycholic acid-3AA, respectively. The MIPs are successfully synthesized by precipitation polymerization using EDGMA as dispersant and AIBN as initiator, and the results of FTIR show that MIPs are well prepared. Therefore, this method can be used for the screening and preparation of MIPs functional monomers with specific selectivity for steranes, and provide technical support for the study of oil-source correlation between deep and ultra-deep source rocks.

Lipstatin or its saturated analog (orlistat), being the irreversible inhibitor of intestinal lipase, is widely used for the treatment of obesity. The bacterium Streptomyces toxytricini is the main source for the production of lipstatin/orlistat. There are continuous attempts to increase the production of lipstatin in S. toxytricini. For optimization of best conditions/strains for lipstatin production, there are requirements for a fast, simple, and reliable method to detect/estimate lipstatin. At present, highly sophisticated methods such as high‐performance liquid chromatography, mass spectrometry, and so forth are available for the detection and estimation of lipstatin/orlistat. These methods are very costly, time‐consuming, and require state of the art facility. Here we report a simple, fast, cost‐effective method based on thin‐layer chromatography for the detection of lipstatin in S. toxytricini. The optimized mobile phase was acetone: ethanol in a ratio of 3:7. Development of thin‐layer chromatography was done by ρ‐anisaldehyde staining that showed the pink color to the silica plate and greenish‐blue color to the lipstatin/orlistat drug. Conclusively, here we mention a simple and reproducible method of detection of orlistat and lipstatin samples extracted from S. toxytricini. [ABSTRACT FROM AUTHOR]

The possibility of obtaining real-time information about the thermodynamic state of the molten metal pool created during additive layer-by-layer deposition of powder material on a substrate surface by laser directed energy deposition (LDED) technique is considered. Current information about the thermodynamic temperature of the molten metal material is important for obtaining predictable properties of parts manufactured using laser-based additive technologies. As a result of the studies carried out, the existence of a linear dependence of the intensity of light radiation from the melt pool in the spectral range (280–380 nm) on the power density of laser radiation has been found. This linear dependence allows to obtain further information about the quality of the LDED process. The obtained scientific and technical solutions for the melt pool temperature control can be used to improve the precision control in laser additive manufacturing of metal parts with stringent quality requirements. Along with this, the results obtained in the work will be used to improve the information base of the decision support system being developed by the team of authors for process engineers of laser robotic equipment. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Henan University of Technology Natural Science Edition is the property of Henan University of Technology Journal Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Due to the increase in electrical power demand, future more electric and all-electric aircraft designs will operate at higher voltage levels compared to current aircraft. Due to higher voltage levels and reduced operating pressure, insulation systems will be at risk. Air is the main insulating medium, and it is well known that its dielectric strength decreases considerably with operating pressure. Although electrical discharges can be detected by different techniques, optical methods are very attractive due to their sensitivity and immunity to acoustic and electromagnetic noise typical of aeronautical environments. This work analyzes the UV-visible spectrum of corona discharges and electric arcs in the 10–100 kPa pressure range, which covers most of the aeronautical applications, due to the lack of experimental data for this pressure range. The data presented in this work are important to select the most suitable optical sensors to detect electrical discharges at an early stage, before significant damage occurs. This approach will help implement preventive maintenance plans and increase aircraft safety. The results presented in this paper can also be applied to other areas, such as monitoring of discharges in power lines, particularly those located in high-altitude regions. [ABSTRACT FROM AUTHOR]

Food additives are utilized in countless food products available for sale. They enhance or obtain a specific flavor, extend the storage time, or obtain a desired texture. This paper presents an automatic classification system for five food additives based on their absorbance in the ultraviolet domain. Solutions with different concentrations were created by dissolving a measured additive mass into distilled water. The analyzed samples were either simple (one additive solution) or mixed (two additive solutions). The substances presented absorbance peaks between 190 nm and 360 nm. Each substance presents a certain number of absorbance peaks at specific wavelengths (e.g., acesulfame potassium presents an absorbance peak at 226 nm, whereas the peak associated with potassium sorbate is at 254 nm). Therefore, each additive has a distinctive spectrum that can be used for classification. The sample classification was performed using deep learning techniques. The samples were associated with numerical labels and divided into three datasets (training, validation, and testing). The best classification results were obtained using CNN (convolutional neural network) models. The classification of the 404 spectra with a CNN model with three convolutional layers obtained a mean testing accuracy of 92.38% ± 1.48%, whereas the mean validation accuracy was 93.43% ± 2.01%.

We investigated the effects of unipolar magnetic fields (N or S polarity) on the physical properties of deionized water. Long-term experiments (15 and 25 days) revealed significant pole-dependent changes in water absorption in the UV range (186 – 230 nm), and in water evaporation. The order of absorption magnitudes was C-N-S. That is, control (C) water absorbed the most, N-pole-influenced water absorbed less, and S pole the least. The differences in absorption between N and S waters were substantial. A correlation between UV absorption values and evaporation rates was also found. The relative order of evaporation rates was the same as the order of the absorption values, also C-N-S. The evaporation rates of N and S waters were less than C water evaporation. The effects of magnetic fields were long term. The interaction of magnetic fields with water is of interest not only from a physical sciences perspective, but also in the context of the significant applications in biophysics and medicine.

The unstable title compound has been characterized for the first time. Its melting point, UV, IR, 1H and 13C-NMR and high-resolution mass spectra are presented. The X-ray structure has also been determined and shows a rather long C–Br bond perpendicular to the otherwise planar molecule.

Due to the increase in electrical power demand, future more electric and all-electric aircraft designs will operate at higher voltage levels compared to current aircraft. Due to higher voltage levels and reduced operating pressure, insulation systems will be at risk. Air is the main insulating medium, and it is well known that its dielectric strength decreases considerably with operating pressure. Although electrical discharges can be detected by different techniques, optical methods are very attractive due to their sensitivity and immunity to acoustic and electromagnetic noise typical of aeronautical environments. This work analyzes the UV-visible spectrum of corona discharges and electric arcs in the 10–100 kPa pressure range, which covers most of the aeronautical applications, due to the lack of experimental data for this pressure range. The data presented in this work are important to select the most suitable optical sensors to detect electrical discharges at an early stage, before significant damage occurs. This approach will help implement preventive maintenance plans and increase aircraft safety. The results presented in this paper can also be applied to other areas, such as monitoring of discharges in power lines, particularly those located in high-altitude regions.

Based on DFT, B3LYP method was used to optimize the structure of 3-tert-butyl-4-hydroxyanisole (BHA) molecule at the level of 6-311g(d,p) set level. On this basis, the first 50 excited states were calculated by using B3LYP/def 2-TZVP method based on TD-DFT with ethanol as solvent. Multiwfn 3.6 software was used to plot the UV spectrum, and three methods including atomic charges, Fukui function (FF) and electrostatic potential (ESP) were used to predict its electrophilic reactive sites. Finally, bond energy of O10–H11 and C12–O13 were investigated by the ωB97XD/TZVP method. Comparing the experimental and theoretical UV spectra, it was found that the overall agreement was good. The oxygen atom on the phenolic hydroxyl group and the oxygen atom on the ether bond are the electrophilic reactive sites. And the C12–O13 bond on the ether bond is more prone to dissociation. They are easily reacted with peroxide radicals to have oxidation resistance. [ABSTRACT FROM AUTHOR]

The theoretical calculation of fentanyl molecule based on DFT is of great significance to understand the properties. The initial conformations were searched by molclus software and two reasonable conformations were selected. The structural optimization of fentanyl using DFT/B3LYP/6-311+G(d,p) method by Gaussian16. Based on this, the first 50 excited states are calculated by using TD-DFT with methanol as the solvent. Multiwfn 3.6 was used to calculate its electrical parameters such as electrostatic potential, average local ionization energy, Fukui function and dual descriptor and draw UV spectrum. From the UV spectrum, the maximum absorption peak is located at 188 nm, which is mainly formed by the σ → σ* transition of the C–C, C–H bond. From the analysis of electrical parameters, the nitrogen atom (N18) on the piperidine ring is an electrophilic reactive site, and it is easily attacked by an electrophilic reagent so that the phenethyl group is replaced by a hydrogen atom to form norfentanyl. [ABSTRACT FROM AUTHOR]

[Display omitted] • The use of UV and fluorescence to detect the Aurelia at different stages of growth. • The fluorescence can be used to distinguish Aurelia from other marine organisms. • The UV spectrum can be used to distinguish the different growth stages of Aurelia. • Such a procedure is green and environment-friendly. Under the dual pressure of human activities and global changes, jellyfish outbreaks have occurred frequently in China's offshore waters in recent years, with serious impacts on marine fisheries, coastal tourism, marine ecology and cooling water systems for coastal industries. In order to accurately identify the origin of Aurelia and to be more proactive in the prevention and control of Aurelia outbreaks, this article proposed the use of ultraviolet (UV) and fluorescence spectroscopy to detect the polyps, ephyrae and larvae of Aurelia at different growth stages. The AvaSpec-2048 UV visible fibre spectrometer and the F-7000 fluorescence spectrophotometer were used to focus on studying the UV absorption spectrum and three-dimensional fluorescence spectrum of the polyps, ephyrae, and larvae of Aurelia cultured under laboratory conditions. The research results showed that the three-dimensional fluorescence spectrum of the three different growth stages of Aurelia, namely polyps, ephyrae and larvae of Aurelia, had relatively similar fluorescence distributions, and the fluorescence intensity was different from each other. However, the absorption peaks of the three UV absorption spectrum appeared in different UV light bands and there were absorption peaks of different intensities. The different spectral characteristics at different growth stages of Aurelia provide new ideas and methods for exploring the birthplace of Aurelia. [ABSTRACT FROM AUTHOR]

In order to investigate spectroscopic features of caffeic acid (CA), the IR, Raman, 13C-NMR, 1H-NMR, and UV spectra of this compound were simulated. For this purpose the B3LYP-D3/6-311+G(d,p) theoretical model was used in combination with CPCM solvation model. Very good agreement between all experimental and simulated spectra was achieved. This result indicates that B3LYP-D3 can be a method of choice in studies that refer to spectroscopic investigations. Spectroscopic features of CA are very similar to those of chlorogenic acid (5-O-caffeoylquinic acid) (MARKOVIĆ, TOŠOVIĆ and DIMITRIĆ MARKOVIĆ, 2016), pointing out the significance of caffeic moiety.

In the present work, a new organic second order NLO material: L-isoleucinium p-toluenesulfonate monohydrate (LIPT) is synthesized and reported for the first time. The LIPT is crystallized in a non-centrosymmetric monoclinic space group P21. Structural and hydrogen bond nature of the compound is analyzed using single crystal X-ray diffraction studies. The crystal exhibits very good optical properties such as wide optical transparency in the region of 210 nm to 1100 nm and the ultraviolet wavelength emission (λ = 283 nm). The second harmonic generation efficiency is found to be 1.7 times the standard KDP. Good thermal, mechanical properties and low dielectric constant at high frequency range show that the material may be a potential candidate for optoelectronic applications. [ABSTRACT FROM AUTHOR]

One of the tasks for creating of a medicinal product which contains hydrogel of vitreous humor (VH), nanosized silica and zinc compound is studying of the regularities of complex formation of hyaluronic acid and protein, as a main macromolecular components of VH, with zinc ions. We have found that after mixing solutions of VH and zinc sulfate the growth of optical density in UV range of the spectrum is observed, apparently due to light scattering as a result of increasing quantity of macromolecular aggregates. It has been proved that this effect is not a consequence of the formation of insoluble compounds due to changes in pH of the medium and thus can be explained by the interaction (complexation) of VH components with zinc ions. In order to determine the regularities of complex formation, the spectrophotometric titration of VH and separately solutions of purified sodium hyaluronate and model protein – bovine serum albumin (BSA) – with zinc ions was carried out. To constant amount of VH (dilution 1:5) increasing amounts of zinc sulfate solution were added, after that UV spectrum was recorded. As it turned out, after addition of zinc sulfate in the concentrations range 2.5–5.0 mass. % the growth of optical density almost immediately becomes maximal and does not depend on the amount of titrant, which can be explained by saturation of all active centers of VH, which include carboxyl groups of hyaluronic acid and electron donor groups of protein: NH2-groups, amide bond, thiogroups, etc. In the range 0–0.5 mass. % of zinc sulfate (0–17.5 mmol/l of Zn2+) there is a gradual increase in optical density, which makes it possible to calculate equilibrium parameters in the system VH + n Zn2+ ↔ VH · (Zn2+)n. For BSA which also demonstrated a gradual increase of optical density in UV range, in order to determine the stoichiometry of BSA · (Zn2+)n complex the method of molar ratios was used, and it was found that there were about 800 ions of Zn2+ per one BSA molecule. In the case of purified sodium hyaluronate, the method of spectrophotometric titration proved to be unsuitable or complexation does not occur at all. Consequently, the interaction of VH with zinc ions is carried out mainly due to the protein component rather than hyaluronan. Dimensional characteristics of aggregates formed as a result of the interaction between VH or BSA and zinc ions were investigated by the method of dynamic light scattering (DLS). [ABSTRACT FROM AUTHOR]

The absorption of 1-butyl-3-methylimidazolium chloride and acetate taken from commercial packaging was studied by means of UV-VIS and infrared spectroscopy with some differences observed. Further research showed that heating both 1-butyl-3-methylimidazolium chloride and acetate alone, as well as in the presence of wood pulp, causes the darkening of these ionic liquids. Changes in the colour of ionic liquids associated with a variation in the absorption characteristics of pure ionic liquids and wood solutions in these liquids in UV and visible light are expressed primarily in the widening of the absorption bands. The presence of coloured products formed during their heating, as well as dissolution of the chemical components of wood in ionic liquids, had relatively little effect on the position of individual absorption bands in the spectrum obtained by the FT-IR method. The small differences in the absorption of spruce groundwood solutions in ionic liquids in IR as compared to pure ionic liquids suggest that strong chromophore groups in ionic liquids are created without serious reconstruction of their structure. [ABSTRACT FROM AUTHOR]

Abstract In this work, we demonstrate a solvent-assisted structural transformation between two 3D metal-organic frameworks (MOFs) ([Zn 4 ( α -bptc) 2 (H 2 O) 3 ] n ( 1 ) → {[Zn 2 ( α -bptc)(H 2 O) 4 ]·(pra)} n ( 2 )) ( α -H 4 bptc = 2,3,3′,4′-biphenyl tetra-carboxylic acid and pra = pyridin-2-amine) at room temperature by immersing complex 1 in a mother solution. The structural transformation involves not only solvent exchange but also the cleavage and formation of coordination bonds, which is confirmed by infrared spectroscopy, single-crystal X-ray diffraction analysis, powder X-ray diffraction patterns, and thermogravimetric analysis. Structural analyses revealed that significant modifications occurred during the transformation including the changes in lattice parameters, unit cell volume, space group, coordination number, secondary building units, and topological type. In the case of drastic structural transitions, significant changes in properties were also observed. Complex 2 displayed the interesting uptake and release of iodine with the changes in visible color, UV and fluorescence spectra, and fully reversible I2 uptake of 8.5 mg g−1, which further suggested about its future application as iodine absorbing material. Graphical Abstract Irreversible solvent-assisted structural transformation between two 3D Zn(II)-MOFs. Unlabelled Image Highlights • A Zn(II) compound 2 based on α -H 4 bptc is synthesized and fully characterized. • Irreversible solvent-assisted structural transformation between two 3D Zn(II)-MOFs. • The transformation is accomplished by coordination bond cleavage and formation. • Complex 2 displays reversible I 2 uptake with visible color change. [ABSTRACT FROM AUTHOR]

Two novel complexes, [Cu (L)(H2O)]⋅H2O (1) and [Mn (H2O)6] ⋅L ⋅H2O (2) (L = 1,4‐bis (pyrazol‐1‐yl) terephthalic acid), were synthesized under hydrothermal conditions. They were characterized using elemental analysis, infrared spectroscopy and single‐crystal X‐ray diffraction. Intramolecular weak interactions, such as hydrogen bonds, and intermolecular interactions play important roles in the construction of the complexes. The interaction of these complexes with fish sperm DNA (FS‐DNA) was monitored and binding constants were determined using UV–visible spectroscopy, which revealed their ability to bind to FS‐DNA, with binding constants for the two complexes of 1.88 × 104 M−1 (1) and 1.06 × 104 M−1 (2). Viscosity experiments further demonstrated the binding of the complexes to DNA. The complexes were further studied using gel electrophoresis assay with supercoiled plasmid pBR322 DNA. In addition, anticancer activities of the metal complexes investigated through MTT assays in vitro indicated good cytotoxic activity against cancer cell lines. Flow cytometry and apoptosis experiments showed that these complexes induced apoptosis of two different cancer cell lines (HeLa and KB cells), demonstrating a significant cancer cell inhibitory rate. Finally, a further molecular docking technique was employed to confirm the binding of the complexes towards the molecular target DNA. [ABSTRACT FROM AUTHOR]

An approach specific for triacylglycerides (TAGs) is proposed for chromatographic separation of compounds with different chromophores using spectrophotometric detection instead of preliminary calibration of the detector using unavailable (or difficultly accessible) reference standards. A wavelength similar to an isosbestic point (278 nm) is found for this approach for TAGs containing radicals of three isomeric conjugated octadecatrienoic acids (COAs) and can be used to determine the ratio of the amounts of TAGs with isomeric radicals without introducing correction factors for the sensitivity of each compound. A mathematical procedure for processing UV spectra of TAGs containing COA radicals is proposed for finding these points. The specifics of the TAG composition allow the isolation and use of highly labile pure compounds to be avoided. The method is developed using seed oils of red valerian (Centranthus DC.), TAGs of which are formed from two isomeric COAs (α- and β-eleosteric), and pomegranate (Punica granatum L.) with radicals of another pair of COAs (punicic and α-eleostearic) as examples. [ABSTRACT FROM AUTHOR]

The present study investigated the synthesis of gold nanoparticles (AuNPs) using mangrove plant extract from Avicennia marina as bioreductant for eco‐friendly bioremediation of 4‐nitrophenol (4‐NP). The AuNPs synthesised were confirmed by UV spectrum, transmission electron microscopy (TEM), X‐ray diffraction, Fourier transmission infrared spectroscopy (FTIR), dynamic light scattering (DLS), and zeta potential. The AuNPs were found to be spherical in shape with size ranging from 4 to 13 nm, as evident by TEM and DLS. Further, the AuNPs were encapsulated with sodium alginate in the form of gold nano beads and used as heterogeneous catalyst and degrading agent to reduce 4‐NP. This reduction in 4‐NP into 4‐aminophenol was confirmed by UV and FTIR. The aqueous solution of 4‐NP peaked its absorbance at 320 nm, and shifted to 400 nm, with an intense yellow colour, appeared due to formation of 4‐nitrophenolate ion. After the addition of AuNps, the 4‐NP solution became colourless and peaked at 400 nm and reduced to 290 nm corresponding to the formation of 4‐aminophenol. Hence, the present work suggested the AuNPs as the potent, eco‐friendly bionanocomposite catalyst for bioremediation of 4‐NP. [ABSTRACT FROM AUTHOR]

Density Functional Theory (DFT) and time dependent density functional theory (TD-DFT) calculations using PBE and TPSS functionals have been performed to investigate the effects of the adsorption of hydrazine (N 2 H 4 ) on the structural and optoelectronic features of the pure and Al defected MgO nanotubes. The calculated results for hydrazine/MgO systems reveal no remarkable changes with respect to optical and electronic features of the pure MgO after interactions. Consequently, the Al substitutions with Mg atoms placed in the middle and end sites have shown significant changes in values of the frontier molecular orbital space distribution and ground state dipole moment of states V and VII after interaction with hydrazine compared to those of hydrazine adsorbed onto pure MgO nanotubes. The quantum molecular descriptor and TD-DFT calculations show that electrons transfer from the HOMO orbitals of Al-defected MgO nanotubes to LUMO, LUMO-1 and LUMO-2 orbitals of hydrazine. This study indicates for sensor applications that Al-defected-MgO nanotubes (states X and Z ) are more likely to facilitate the hydrazine detection compared to pure MgO nanotubes. [ABSTRACT FROM AUTHOR]

Background: To protect renewable packaging materials against autoxidation and decomposition when substituting harmful synthetic stabilizers with bioactive and bio-based compounds, extracts from Aesculus hippocastanum L. seeds were evaluated. The study objectives were to determine the antioxidant efficacy of bioactive compounds in horse chestnut seeds with regard to different seed fractions, improve their extraction, and to evaluate waste reuse. Methods: Different extraction techniques for field samples were evaluated and compared with extracts of industrial waste samples based on total phenolic content and total antioxidant capacity (2,2’-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS)). The molecular weight distribution and absorbance in ultraviolet range (UV) of seed coat extracts were determined, and the possibility of extracts containing proanthocyanidins was examined. Results: Seed coat extracts show a remarkable antioxidant activity and a high UV absorbance. Passive extractions are efficient and much less laborious. Applying waste product seed coats leads to a reduced antioxidant activity, total phenolic content, and UV absorbance compared to the field sample counterparts. In contrast to peeled seed extracts, all seed coat extracts contain proanthocyanidins. Discussion: Seed coats are a potential source of bioactive compounds, particularly regarding sustainable production and waste reuse. With minimum effort, highly bioactive extracts with high potential as additives can be prepared.

The UV absorption spectrum and the photolysis reaction kinetics of 4-hydroxy-3-hexanone (4H3H) in the 275–330 nm region have been investigated for the first time. The photolysis frequency of this compound in the atmosphere was evaluated using actinometry and found to be J 4H3H,atm = (5.9 ± 3.1) × 10 −3 h −1 . An atmospheric effective quantum yield was estimated to about 10% and a photolysis lifetime of about 7 days was determined. The comparison with the reactivity of other hydroxyketones suggests that the kinetics of hydroxyketones photolysis depends on their structure, mainly the branching and the proximity of the two functions. [ABSTRACT FROM AUTHOR]

The chemical composition and the antioxidant properties of Capsicum annum discarded seeds from processing industry with their corresponding extracted oil were investigated. C. annum seeds had high levels of crude proteins (18.30%), crude oil (11.04%), and dietary fibers (60.96%). The lipophilic fraction of C. annum seeds showed higher radical scavenging activity compared to their hydrophilic fraction, while this latter exhibited the highest reducing power. The results of fatty acid composition showed that fatty acids present in C. annum seed oil were mainly polyunsaturated (84.23%), with linoleic acid being the major polyunsaturated fatty acid (70.93%). The major monounsaturated fatty acid was oleic acid (12.18%), while the main saturated fatty acid was palmitic acid (11.90%). C. annum seed oil showed high absorbance in the UV-B, UV-A, and visible ranges. Owing to their composition, C. annum seeds discarded from pepper processing industry as by-product could be potentially used as high added-value ingredients in some food or nutraceutical formulations because they are well endowed with essential nutriments required for human health. [ABSTRACT FROM AUTHOR]

Copyright of Research of Environmental Sciences is the property of Research of Environmental Sciences Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Two isomeric dinuclear Cerium(II) complexes 1 and 2, formulated as Ce 2 (phen) 2 (NO 3 ) 2 (L) 4 [L = phenylacetic acid, phen = 1,10-phenanthroline] was synthesized under solvothermal conditions at different pH values. The two complexes were characterized by elemental analysis, IR and single crystal X-ray diffraction. Complexes 1 and 2 were studied the binding with DNA and against cytotoxic activity. Fluorescence analysis indicated that the two complexes can bind to DNA. The changes with different gradient concentration of DNA added into the complexes in absorption spectra show a strongπ-stacking interaction between the complexes and DNA base pairs. The Cerium(II) complexes showed good cytotoxic activity against cancer cell lines, being 2 the most potent complex. Apoptotic studies of the two novel dinuclear complexes showed significant inhibitory rate on cancer cell growth line KB. [ABSTRACT FROM AUTHOR]

Various hydrophilic γ-cyclodextrin (CD) thioethers, containing neutral or ionic side arms were found to form molecular disperse solutions of C60 in water reaching concentrations of 15 mg/L. Equilibrium state was approached after seven days without the use of organic cosolvents. The 1:2 stoichiometry of the C60/γ-CD thioether complexes was demonstrated by a parabolic phase-solubility diagram. In contrast, native γ-CD forms nanoparticles with C60. Particle sizes of C60 were determined by dynamic light scattering.

The linear conjugated compounds are a class of important organic compounds with good ultraviolet (UV) absorption, which are usually employed as the parent molecules of a lot of optical materials. The traditional topological quantum chemistry approach can accurately predict the UV absorption energies of unsubstituted linear conjugated alkenes. However, for the alkyl-substituted conjugated alkenes, this approach seems unsatisfactory. It is known that the π conjugated chain is a good conductor for the electron mobility, while the alkyl substituent is a bad one. As a result, their influences on the π electron transition will be different from each other. In order to distinguish the contribution of these two different structural parts, a substructure approach was proposed, in which a substituted linear conjugated molecule was divided into two substructures: the π conjugated chain part and the substituent part. Different methods were employed to characterize their structures. The relative frontier orbital energy gap of the conjugated chain ( Δ RE HL 0 ) and the polarization energy of the substituents (P RE ) were calculated by substructure-based topological quantum chemistry method. A good linear regression model was built between the UV absorption wavenumbers and two parameters Δ RE HL 0 and P RE for 23 typical conjugated alkenes. Based on this model, the UV absorption wavenumbers of other 70 alkenes were also predicted with high accuracy. This substructure-based topological quantum chemistry method was also extended to the investigation of the UV absorption of 89 olefinic aldehydes and ketones, and good results were also obtained. [ABSTRACT FROM AUTHOR]

Although chlorogenic acid (5- O -caffeoylquinic acid, 5CQA ) is a dietary polyphenol known for its pharmacological and nutritional properties, its structural features have not been completely elucidated. This is the first study whose aim is to contribute to clarification of the 5CQA structure by comparing the experimental and simulated IR, Raman, 1 H NMR, 13 C NMR, and UV spectra. For this purpose, a comprehensive conformational analysis of 5CQA was performed to reveal its most stable conformations in the gas-state and solution (DMSO and methanol). The lowest-energy conformers were used to predict the spectra at two levels of theory: B3LYP-D3/and M06-2X/6–311+G(d,p) in combination with the CPCM solvation model. Both methods provide very good agreement between all experimental and simulated spectra, thus indicating correct arrangement of the atoms in the 5CQA molecule. The quinic moiety is characterized with directed hydrogen bonds, where the carboxylic hydrogen is not oriented towards the carbonyl oxygen of the carboxylic group, but towards the oxygen of the proximate hydroxyl group. In the gas-state the lowest-energy conformers are characterized with the O4 H4 ⋯ O9′ hydrogen bond, whereas in the solvated state the structures with the O4 H4 ⋯ O10′ hydrogen bond prevail. Knowing the fine structural details, i.e. the proper conformation of 5CQA , provides a solid base for all further investigations related to this compound. [ABSTRACT FROM AUTHOR]