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The photosensitized reaction of nitrobenzene and its derivatives, including dinitrobenzene, has been extensively investigated in an aqueous alkaline medium using Benzophenone as a sensitizer under visible light irradiation. A 100 W tungsten lamp was employed for the purpose of irradiation. The presence of the strongly electron-withdrawing NO2 group leads to polarization of the C–H bond. In this process, the triplet excited state of benzophenone initiates H+ abstraction from the polarized C–H bond of nitrobenzene (NB) and meta-dinitrobenzene (m-DNB) through exciplex formation. Proton abstraction results in the formation of free radicals for both NB and m-DNB, followed by dimerization of the free radicals. The observed rate of the reaction follows the order m-DNB > NB. However, no photochemical reaction was observed for p-dinitrobenzene (p-DNB). Various parameters such as pH, substrate concentration, sensitizer concentration, light intensity, solvent effect, and the rate of the photochemical reaction were investigated. The quantum efficiency of the product was determined using a potassium ferrioxalate actinometer. The formation of the product occurs through exciplex formation from the triplet excited state. The possible products, namely 2,2'-dinitro biphenyl and 2,2'-4,4'-tetranitro biphenyl, were confirmed using UV–visible spectrophotometry and mass spectrometry. Finally, a proposed reaction mechanism was suggested based on the experimental findings. [ABSTRACT FROM AUTHOR]

Melanoma, an aggressive and potentially fatal skin cancer, is constrained by immunosuppression, resistance, and high toxicity in its treatment. Consequently, there is an urgent need for innovative antineoplastic agents. Therefore, this study investigated the antimelanoma potential of guttiferone E (GE). In an allogeneic murine B16 melanoma model, GE was administered subcutaneously and intraperitoneally. Antitumor evaluation included tumor volume/weight measurements and histopathological and immunohistochemical analysis. Furthermore, the toxicity of the treatments was evaluated through body/organ weights, biochemical parameters, and genotoxicity. Subcutaneous administration of 20 mg/kg of GE resulted in a significant reduction in both tumor volume and weight, effectively suppressing melanoma cell proliferation as evidenced by a decrease in mitotic figures. The tumor growth inhibition rate was equivalent to 54%. This treatment upregulated cleaved caspase-3, indicating apoptosis induction. On the other hand, intraperitoneal administration of GE showed no antimelanoma effect. Remarkably, GE treatments exhibited no toxicity, evidenced by non-significant differences in body weight gain, as well as organ weight, biochemical parameters of nephrotoxicity and hepatotoxicity, and genotoxic damage. This study revealed, for the first time, the efficacy of subcutaneous administration of GE in reducing melanoma, in the absence of toxicity. Furthermore, it was observed that the apoptotic signaling pathway is involved in the antimelanoma property of GE. These findings offer valuable insights for further exploring GE's therapeutic applications in melanoma treatment. [ABSTRACT FROM AUTHOR]

Previously, we found that the ultraviolet filter benzophenone-3 (BP3) causes fetal growth restriction in mice when is applied when implantation occurs (first week of gestation). However, whether BP3 can affect gestation and fertility after implantation period is unknown. We aimed to study the effects on reproductive physiology of the offspring caused by perinatal exposure to BP3. C57BL/6 pregnant mice were dermally exposed to 50 mg BP3/kg bw.day or olive oil (vehicle) from gestation day 9 (gd9) to postnatal day 21 (pnd1). We observed no differences in mother's weights, duration of gestation, number of pups per mother, onset of puberty or sex ratio. The weights of the pups exposed to benzophenone-3 were transiently lower than those of the control. Estrous cycle was not affected by perinatal exposure to BP3. Besides, we performed a fertility assessment by continuous breeding protocol: at 10 weeks of age, one F1 female and one F1 male mouse from each group was randomly chosen from each litter and housed together for a period of 6 months. We noticed a reduction in the number of deliveries per mother among dams exposed to BP3 during the perinatal period. To see if this decreased fertility could be associated to an early onset of oocytes depletion, we estimated the ovarian reserve of germ cells. We found reduced number of oocytes and primordial follicles in BP3. In conclusion, perinatal exposure to BP3 leads to a decline in the reproductive capacity of female mice in a continuous breeding protocol linked to oocyte depletion. [ABSTRACT FROM AUTHOR]

In this study, we investigate the adsorption behavior of three benzophenone derivatives, namely 2,4-Dihydroxybenzophenone (benzophenone-1; BP-1), 2,2′,4,4′-tetrahydroxybenzophenone (benzophenone-2; BP-2), and 2-hydroxy-4-methoxybenzophenone (benzophenone-3; BP-3) on the surfaces of graphene oxide (GO) using density functional theory method. The geometric optimization of the unaltered structures of GO adsorbent, benzophenone derivatives, and their respective complexes was conducted via the M052X/6-311 + G* level of theory. The optimal temperature for the interaction between the GO adsorbent and BPs pollutants in the aqueous phase was found to be 298.15 K. The adsorption process was found to be spontaneous, exothermic, and irreversible based on the calculated values of adsorption energy, Gibbs free energy (ΔGad), and enthalpy (ΔHad). The negative values of the calculated chemical potential for all structures indicated that the studied structures were thermodynamically stable. The adsorption of BP-2 pollutant on the surface of GO results in a highest dipole moment (μd = 28.22 D) compared to the corresponding unadsorbed molecule (μd = 7.93 D). The adsorption efficiency of GO–BPs complexes follows an increasing trend of GO–BP-2 (−1009.75 kcal/mol) > GO–BP-3 (−1006.31 kcal/mol) > GO–BP-1(−1000.65 kcal/mol). Moreover, infrared (IR) frequency calculations confirmed the feasibility of the structures, showing true local minima. The recovery time values indicate that GO is a highly effective adsorbent in removing organic BP-2 pollutants ( τ = 3.158 ms) from aqueous media rather than BP-3 ( τ = 2.120 ms) and BP-1 ( τ = 1.831 ms) counterparts. Other key parameters engaged in the adsorption behavior of considered molecules, including charge capacity, electrophilicity, band gap, chemical potential, and chemical hardness, were also deliberated. [ABSTRACT FROM AUTHOR]

Chemical bond cleavage by electron transfer to an organic molecule is a typical electro-initiated reaction; however, there are few examples of carbon—carbon bond cleavage. In this study, using cyclic voltammetry, chronoamperometry, controlled-potential electrolysis with chromatographic characterization of products, and ab initio quantum chemical calculations, it was shown that the electrochemical reduction of benzopinacol (1,1,2,2-tetra-phenyl-1,2-ethanediol) in aprotic solvents (DMF, MeCN, THF) in the presence of Bu4NClO4 as a supporting electrolyte is accompanied by cleavage of the central C–C bond, which follows the electron transfer. This initiates a chain reaction giving equimolar amounts of benzophenone and benzhydrol (diphenylmethanol). The decomposition is inhibited in the presence of medium-strength proton donors (phenol, benzoic and acetic acids, etc.) in the solution. A similar effect is attained by the addition of divalent metal salts, in particular Mg(ClO4)2. According to the results of quantum chemical calculations, the effective C–C bond cleavage in the benzopinacol radical anion to give a radical and an anion is due to a very low energy barrier (1.7 kcal mol−1) and is very thermodynamically favorable (ΔG°298 = −16.6 kcal mol−1). [ABSTRACT FROM AUTHOR]

Organic UV filters (OUVFs), the active ingredient in sunscreens, are of environmental concern due to reported ecotoxicological effects in aquatic biota. Determining the environmental concentrations of these chemicals is essential for understanding their fate and potential environmental risk. Salting‐out assisted liquid–liquid extraction (SALLE) coupled with liquid-chromatography tandem mass spectrometry (LC–MS/MS) was developed for simultaneous extraction, separation, and quantification of seven OUVFs (2,4-dihydroxybenzophenone, 2,2′,4,4′-tetrahydroxybenzophenone, 4-methylbenzylidene camphor, butyl-methoxy-dibenzoyl methane, octocrylene, octyl methoxycinnamate, and oxybenzone). Method detection limits (MDLs) ranged from 11 to 45 ng/L and practical quantification limits (PQLs) from 33 to 135 ng/L. Method trueness, evaluated in terms of recovery, was 69–127%. Inter-day and intra-day variability was < 6% RSD. The coefficients of determination were > 0.97. The method was applied to river and seawater samples collected at 19 sites in and near Port Phillip Bay, Australia, and temporal variation in OUVF concentrations was studied at two sites. Concentrations of OUVF were detected at 10 sites; concentrations of individual OUVFs were 51–7968 ng/L, and the maximum total OUVF concentration detected at a site was 8431 ng/L. Recreational activity and water residence time at the site contributed to OUVF's environmental presence and persistence. The benefits of the SALLE-LC–MS/MS method include its simple operation, good selectivity, precision over a wide linear range, and that obtained extracts can be directly injected into the LC–MS/MS, overall making it an attractive method for the determination of these OUVFs in environmental water matrices. To our knowledge, this is the first report of the occurrence of OUVFs in Port Phillip Bay, Australia. [ABSTRACT FROM AUTHOR]

The process of midazolam ring closure was studied from the thermodynamic and kinetic points of view by means of quantum-chemical methods. B3LYP/6–311 + + G(d,p) model was employed for gas phase and water environment (polarizable continuum model) calculations. It was concluded that the reaction rate determining step is the first step—carbinolamine formation from amine and carbonyl ends of the opened benzodiazepine ring. The Gibbs free energy of activation was calculated as 35.1 kcal/mol for gas- phase and 33.9 kcal/mol for water environment. Intrinsic reaction coordinate calculations were performed to verify that the transition state really connects the substrate and product. Thermodynamically, this reaction is endoergic with ΔG = 9.6 kcal/mol for gas phase and 10.0 kcal/mol for water environment. However, the next step—carbinolamine protonation with immediate water molecule loss is expected to be fast and activation barrierless, which enables further progress of the ring closure, despite the positive ΔG of the fist step. Next, the protonated imine undergoes deprotonation to final closed ring, pharmacologically active molecule of midazolam. The whole chain of reaction is exoergic with ΔG equal to − 5.6 kcal/mol for gas phase and − 7.7 kcal/mol for water environment. In order to understand the role of other than benzodiazepine/imidazole molecular fragments on the ring closure process, a model was build which contains only benzodiazepine and imidazole rings. The activation barrier for the carbinolamine formation of the model is similar to midazolam in the gas phase but higher by about 10 kcal/mol for water environment. The most interesting difference is however that for the model, the carbinolamine formation step is exoergic with ΔG equal to − 2.2 kcal/mol for gas phase and − 1.8 kcal/mol for water environment. This difference can be connected to complicated conformational shape of the midazolam molecule, which during the ring closure undergoes unfavorable deformations with accompanying rise of the energy of the molecule. The protonation sites for both midazolam and the model were also studied. In the case of midazolam, the preferred protonation site is the imidazole ring nitrogen atom, but in the case of the model it is the benzodiazepine ring nitrogen atom. The aromaticity of the 5- and 7-membered rings were analyzed using two aromaticity—HOMA and pEDA. It follows that larger stability of the cation protonated at the benzodiazepine ring is accompanied with substantial increase of the 7-ring aromaticity in the model of midazolam. The complexes of midazolam and its model with a water molecule were analyzed because they are needed for evaluation of the energy of the whole process of ring closure. In the case of midazolam, the water molecule preferentially connects to imidazole ring, but in the case of the model, complexes with both imidazole and benzodiazepine rings have similar stability. [ABSTRACT FROM AUTHOR]

A new benzophenone derivative, hyperinagasone (1), has been isolated from the aerial part of Hypericum nagasawae together with six known compounds, trichadonic acid (2), norathyriol (3), euxanthone (4), subalatin (5), hyperielliptone D (6), and 1,4-O-diferuloylsecoisolariciresinol (7). The structure of new compound 1 was determined through spectroscopic and MS analyses. Among the isolates, compounds 2, 4, and 7 exhibited cytotoxicities, with IC50 values of 17.25 ± 1.55, 18.14 ± 1.07, and 10.31 ± 0.92 μM, respectively, against the DLD-1 cell line. Compounds 2, 5, and 7 also exhibited cytotoxicities, with IC50 values of 15.10 ± 1.13, 15.89 ± 0.94, and 17.54 ± 1.16 μM, respectively, against the CCRF-CEM cell line. Norathyriol (3) and 7 exhibited cytotoxicities, with IC50 values of 19.62 ± 2.88 and 6.26 ± 0.50 μM, respectively, against HL-60 cell line. Hyperinagasone (1) and 1,4-O-diferuloylsecoisolariciresinol (7) exhibited cytotoxicities, with IC50 values of 16.83 ± 1.55 and 11.38 ± 0.87 μM, respectively, against the IMR-32 cell line. In addition, 3, 4, and 7 showed potent inhibition, with IC50 values of 5.89 ± 0.43, 7.55 ± 0.54, and 8.12 ± 0.91 μM, respectively, against LPS-induced NO generation. [ABSTRACT FROM AUTHOR]

The study focuses on a non-stringent, rapid and sustainable way for the synthesis of silver oxide nanoparticles (Ag2ONPs) using aqueous rhizome extract of Curcuma zanthorrhiza Roxb. (Cz). High resolution liquid chromatography mass spectroscopy (HR-LCMS) was used for the simultaneous identification of bioactive molecules in the aqueous rhizome extract and its biosynthesized nanoparticles. The presence of eleven bioactive molecules in the rhizome extract acts as reducing and capping agents during the synthesis of Ag2ONPs. The molecules coated to Ag2ONPs were identified to be majorly sesquiterpenoids and lipid molecules. The analytical techniques used for the nanoparticle characterization included UV–Visible spectrum, which showed SPR band at 409 nm; FTIR spectrum depicted the bioactive molecules involved in capping and reduction of silver ions to silver oxide nanoparticles; XRD pattern attributed to fcc structure of CzAg2ONPs with an average size of 39.7 nm; HR-TEM and FESEM confirmed the size and morphology of CzAg2ONPs. The chemical nature of the bioactive molecules bound to Ag2ONPs revealed by HR-LCMS was in agreement with FTIR spectral data. The CzAg2ONPs exhibited efficient photocatalytic activity in the degradation of the toxic dye malachite green (MG) as revealed by the absorption spectra. The degraded product was subjected to HR-LCMS and found to be non-toxic. The results revealed the promising potential of bioactive molecules coated Ag2ONPs for environmental cleanup. [ABSTRACT FROM AUTHOR]

In the present study, novel polypentane maleate (PPM)/ linear low-density polyethylene (LLPE) composites for potential medical disposables application as biodegradable pads were prepared. Polypentane maleate as biodegradable polyester was prepared by adding stoichiometric amounts of maleic acid and pentane diol in presence of titanium tetrabutoxide as a catalyst. FT-IR, 1HNMR and GPC were performed to elucidate the chemical structure of the prepared polymer. Preparation of oxo-degradable polymers (OBP) were achieved by compounding PPM, cellulosic fibers (CF) and LLPE. Synthetic prodegradant such as benzophenone and promising natural prodegradant such as extracted chlorophyll were added to the prepared composites. The polymeric composites were exposed to UV irradiation for different period to evaluate their oxo-degradation behavior. Carbonyl indices were calculated for oxo-degradable polymers using FT-IR spectroscopy. Furthermore,.X- Ray diffraction and differential scanning calorimetry (DSC) were conducted to follow up the crystallinity of the prepared samples. Mechanical properties for polymeric composites were evaluated before and after UV exposure. Morphology of the polymeric composites was investigated by scanning electron microscope. DSC analysis showed that chlorophyll enhances the decrease of crystallinity rather than benzophenone. As well as, mechanical results revealed that chlorophyll lowers tensile strengths after 20 days of UV exposure less than in case of benzophenone. These results confirm that chlorophyll is efficient prodegradant. [ABSTRACT FROM AUTHOR]

Reigning of the abnormal gene activation associated with survival signalling in lung cancer leads to the anomalous growth and therapeutic failure. Targeting specific cell survival signalling like JAK2/STAT3 nexus has become a major focus of investigation to establish a target specific treatment. The 2-bromobenzoyl-4-methylphenoxy-acetyl hydra acetyl Coumarin (BP-1C), is new anti-neoplastic agent with apoptosis inducing capacity. The current study was aimed to develop antitumor phramacophore, BP-1C as JAK2 specific inhibitor against lung neoplastic progression. The study validates and identifies the molecular targets of BP-1C induced cell death. Cell based screening against multiple cancer cell lines identified, lung adenocarcinoma as its specific target through promotion of apoptosis. The BP-1C is able to induce, specific hall marks of apoptosis and there by conferring anti-neoplastic activity. Validation of its molecular mechanism, identified, BP-1C specifically targets JAK2Tyr1007/1008 phosphorylation, and inhibits its downstream STAT3Tyr705 signalling pathway to induce cell death. As a consequence, modulation in Akt/Src survival signal and altered expression of interwoven apoptotic genes were evident. The results were reproducible in an in-vivo LLC tumor model and in-ovo xenograft studies. The computational approaches viz, drug finger printing confers, BP-1C as novel class JAK2 inhibitor and molecular simulations studies assures its efficiency in binding with JAK2. Overall, BP-1C is a novel JAK2 inhibitor with experimental evidence and could be effectively developed into a promising drug for lung cancer treatment. [ABSTRACT FROM AUTHOR]

Benzophenone (BP) and diethyl phthalate (DEP)—chemical substances of environmental concern due to potential toxicity—have been quantified in considerable concentrations in different environmental matrices worldwide. Wastewater treatment plants (WWTPs) with multi-stage hybrid biological systems have been considered a potential strategy to improve the removal of different micropollutants in wastewater from biological systems. On the other hand, investigations on the efficiency of these systems to treat real wastewater with focus on the removal of DEP are scarce, and there is no information on the removal of BP. The aim of this study was to evaluate the performance of a pilot-scale multi-stage hybrid bioreactor (MSHR) on the efficiency of BP and DEP removal from a real wastewater, whose composition varies over short periods of time, thus causing impacts on biological processes. The efficiency of the biological treatment was assessed in two different phases: (I) predominantly suspended biomass and (II) predominantly fixed biomass, both in the aerobic tank. Besides, this study presents and discusses the correlation between BP and DEP removal and different physical–chemical parameters and operating conditions. The highly variable composition of the influent illustrated by the variation in the organic load resulted in oscillation in the treatment performance. Despite this variation, the pilot-scale multi-stage hybrid bioreactor was able to remove up to 69.6% of BP and 74.5% of DEP, both in the phase of predominantly fixed biomass. [ABSTRACT FROM AUTHOR]

A theoretical study on the multi-channel hydrogen addition of maleimide containing 2-hydroxy-benzophenone onto polyethylene in ultra-violet (UV) radiation cross-linking process was carried out using density functional theory (DFT) method at the B3LYP/6–311 + G(d,p) level. The energetic information and the minimum energy path (MEP) are calculated for nine reaction channels. The electrophilic addition reactions at two positions in the target molecule (maleimide containing 2-hydroxy-benzophenone) were investigated, which are on the C atom of C = C groups and on the O atom of C = O groups. Frontier molecular orbitals (MOs) and natural bond orbital (NBO) charge population of the target molecule have been analyzed in detail. As a result, the reaction site of C in C = C group is more active than the site of O in C = O groups. The target molecule can be used as a multi-functional additive candidate. The predicted mechanism may provide a theoretical basis for the real application of cross-linked polyethylene (XLPE) high-voltage insulation cables. [ABSTRACT FROM AUTHOR]

A new benzophenone derivative, hyperinokone (1), has been isolated from the aerial part of Hypericum nokoense, together with six known compounds. The structure of the new compound 1 was determined through spectroscopic and MS analyses. Among the isolates, isojacareubin (4), 5,4′ -dihydroxy-3′ -methoxy-(6:7)-2,2-dimethylpyranoflavone (5), and eleocharin A (6) exhibited cytotoxicities, with IC50 values of 4.16, 6.28, and 5.98 μM, respectively, against the DLD-1 cell line. Compounds 4 and 6 exhibited cytotoxicities, with IC50 values of 5.24 and 4.79 μM, respectively, against the IMR-32 cell line. In addition, 3, 4, and 6 showed potent inhibition with IC50 values of 7.67, 6.03, and 10.52 μM, respectively, against LPS-induced NO generation. [ABSTRACT FROM AUTHOR]

Two new boronic ester conjugated benzophenone derivatives are reported, which exhibit visible afterglow phosphorescence under ambient conditions and solution-processable thin films. The carbonyl group and pinacol moiety in the molecular design play a crucial role to achieve good phosphorescence efficiency in air. [ABSTRACT FROM AUTHOR]

The effect of electronic properties of substituents in the reactants on the [4+2]-cycloaddition of 3-vinyl-chromen-4-ones (dienes) and N-vinylpyrrolidines (dienophiles) has been studied. The conditions determining the formation of 4,4a-dihydroxanthones or benzophenones as the major products have been found. The aromatization of 4,4a-dihydroxanthones via pyran ring opening has been interpreted by quantum chemical calculations. A wide series of new 4,4a-dihydroxanthone and benzophenone derivatives have been isolated. [ABSTRACT FROM AUTHOR]

In present study, a new method based on the support vector machine (SVM) approach was employed to calculate the oil–water permeation flux and grafting yield of maleic anhydride and hyperbranched polyethylene glycol (PEG) on the polyethersulfone (PES) membrane surface. A set of 7 input/output experimental data was applied for training and testing the results of the model. The results of the developed SVM model showed good compliance with the experimental data, as the value of correlation index for the developed model is 0.96, 0.95 and 0.98 for the maleic anhydride and hyperbranched PEG grafting and oil–water permeation flux, respectively. The model was also validated against the kinetic reaction of benzophenone formation on the PES membrane which derives from combination of benzophenone formation reactions and the Lambert–Beer law. Also, to validate the SVM results, the oil–water permeation flux and antifouling characteristics of the modified and neat membranes were investigated, and based on the results, the SVM can be considered as a strong modeling approach in membrane process technologies. [ABSTRACT FROM AUTHOR]

The novel series of piperidine conjugated benzophenone analogs with amide link 11a–l were synthesized in a multistep process. The structures of these compounds were confirmed by IR, 1H, 13C, NMR, and mass spectra and also by elemental analyses. The newly synthesized molecules were screened for selectivity against cancers of different origin through cell based assay system using B16F10, A375, A549, HepG2, ACHN, and MCF7 cells. The results postulated that compound 11f with two bromo groups at the para position in rings A and E and two methyl groups at ortho position in rings B and D evokes target specific action against melanoma highlighting the importance of substituted groups. Down the line studies further inferred compound 11f evokes the apoptotic cellular event leading to cell death. Investigation of eventual mechanism revealed that compound 11f turned out to be a dual inhibitor of B-cell lymphoma-2 and X-linked inhibitors of apoptosis causing the up regulation of Bax and Bad. Further, the antiproliferative effects were mimicked in murine melanoma with similar mechanisms. Molecular docking experiments further confirmed that compound 11f possessed a superior affinity for of B-cell lymphoma-2 and X-linked inhibitors of apoptosis through strong hydrogen bonds. The study implies the identification of compound 11f with selective target against melanoma by inducing apoptogenic effect, which could be the future hope for the treatment of skin cancer. [ABSTRACT FROM AUTHOR]

Core-crosslinked star polymers, which have polyethylene oxide (PEO) as a shell and cross-linked poly(2-{4′-iodobenzoyloxy}-ethyl methacrylate) (PIEMA) with benzophenone derivatives as a core, have been successfully synthesized by an "arm-first" method. PEO-b-PIEMA was prepared via atom transfer radical polymerization (ATRP) of 2-{4′-iodobenzoyloxy}-ethyl methacrylate (4-IEMA) with preformed PEO-Br as a macroinitiator. Core-crosslinked star polymers (CCSP) were efficiently synthesized by ultrafast carbonylation reactions under air by flash microwave irradiation in the presence of dicobalt octacarbonyl in 6 min. Gel permeation chromatography (GPC) trace of CCSP showed a drastic shift to a higher molecular weight when compared to precursor polymer, PEO-b-PIEMA diblock copolymer, indicating that the carbonylation reaction was fully progressed. The CCSP with benzophenone was successfully immobilized on a silicon wafer through a photochemical reaction under UV irradiation. [ABSTRACT FROM AUTHOR]

The impacts of three commonly used benzophenone-type UV filters including benzophenone (BP), 2-hydroxy-4-methoxy-benzophenone (BP3), and 2-hydroxy-4-methoxy-benzophenone-5-sulfonicacid (BP4) were assayed in vitro using a cladoceran Daphnia carinata. The 24-h LC50 on D. carinata calculated for BP, BP3, and BP4 was 8.37, 2.18, and 82.27 mg l−1, respectively. BP3 and BP4 significantly impacted on the time of D. carinata first molting at a concentration of 0.1 µg l−1. BP4 had an inhibitory effect on D. carinata molting and BP3 had an inhibitory effect on D. carinata pregnancy at a concentration of 1 µg l−1. Furthermore, BP4 significantly inhibited the number of D. carinata first brood per female at a concentration of 10 µg l−1. All of the endpoints from acute and chronic toxicity demonstrated that the hydroxy group in BP3 and BP4 significantly enhanced the toxic effect compared to BP. Therefore, the toxicity of BP-type UV filters is related to their molecular structure. [ABSTRACT FROM AUTHOR]

Sensitized phosphorescence of naphthalene-d8 with a lifetime of 14.7 s at 22°C has been obtained in the supramolecular complex "naphthalene-d8–β-cyclodextrin–cyclohexane–benzophenone" and attributed to T–T energy transfer upon excitation of benzophenone at 365 nm. The geometric structure of this complex, energies of singlet transitions, and oscillator strengths have been calculated by quantum-chemistry methods. [ABSTRACT FROM AUTHOR]

The results of kinetic studies of the recombination of radicals in the cage and in bulk of polymers obtained by nanosecond laser photolysis are summarized. The films of rubbers (poly(ethylene-co-butylene)), biaxially oriented polypropylene depending on the preliminary heat treatment, polystyrene, craton (polystyrene-block-poly(ethylene-butylene)-block-polystyrene), silicones, and acrylates are studied. By direct observation, the significant effect of the magnetic field on the kinetics of the recombination of radicals both in the cage and in the bulk of rubber films is recorded. Stretching the rubber film significantly delays the escape of radicals from the matrix cage and, accordingly, bimolecular recombination in the bulk (when stretched 3 times, both processes slow down by a factor of 2). The effect is significantly higher that that expected based on the change in the free volume of the polymer. The increased content of polypropylene in the rubber leads to a stronger cage effect due to the slower escape of radicals into the bulk; at the same time, the recombination rate in the bulk increases and the reaction takes place in the restricted areas of the polymer matrix. The comparative analysis of the kinetic characteristics in polymer of different classes is carried out. [ABSTRACT FROM AUTHOR]

A series of NiB-x (x denotes as the molar ratio of hydrogelator:Ni) amorphous alloys were prepared using a hydrogelator, 2,4-(3,4-dichlorobenzylidene)-D-sorbitol (DCBS), as the controlling agent and were tested in the selective hydrogenation of benzophenone to benzhydrol. The effect of different amounts of DCBS addition on the activity of the NiB amorphous alloys was investigated. The addition of small amounts of DCBS during NiB preparation could markedly improve its activity. The conversion of benzophenone was 96.6% and the yield of benzhydrol can reach 82.0% under the optimal reaction conditions over the NiB-0.015 catalyst. The high activity of NiB catalysts is attributed to the regulation effect of three-dimensional networks formed by DCBS, which could inhibit the agglomeration of NiB particles during preparation and make them more dispersed, resulting in larger surface areas and more active Ni sites. The Brunauer-Emmett-Teller method, transmission electron microscopy, H2-chemisorption and temperature-programmed desorption of hydrogen measurements indicated these results. [ABSTRACT FROM AUTHOR]

Composite films of waste polyethylene (WPE) hoses containing carbon black (CB) as UV-stabilizer, and benzophenone (BP) as UV-absorber and photo-sensitizer were prepared. The effect of both CB and BP on the WPE hoses has been studied under the influence of thermal aging. Prepared composites before and after aging were subjected to gamma radiation at 50 kGy and characterized by determining the carbonyl index derived from FTIR, mechanical parameters, DSC, TGA, and SEM. Remarked improvement in the mechanical and thermal parameters were generally determined by the incorporation of CB and BP. Furthermore, melting temperature of composites after aging did not change with CB/BP loaded and reduces the effectiveness of the biodegradability of the films. The mechanism suggested that biodegradation rates were reduced with incorporation of both CB/BP and the composites become more resists to photo-degradation. [ABSTRACT FROM AUTHOR]

This reconnaissance study was undertaken to examine the occurrence of common ultraviolet filters (UVF) and light stabilizers (UVLS), and preservatives in four different estuaries in Port Philip Bay, Victoria, for the first time. In total, 11 UV filters, 10 UV stabilizers, 12 preservatives and a metabolite, and one fragrance were screened in grab samples of water and sediment using a combination of solid phase extraction and gas and liquid chromatography mass spectrometry measurement techniques. In that context, 16 of the UVF and UVLS and 5 of the preservatives screened were observed in water and/or sediment samples. There are no marine water quality guideline values for any of the fragrances, preservatives and UV filters and light stabilizers in Australia’s current national water quality guidelines, so potential risk was assessed using the risk quotient (RQ) and toxic unit (TU) concepts. In that context, only two chemicals (OC and EHMC) had both an RQ above 1 and a log10TU above − 3, suggesting that few of the screened chemicals would have posed an individual, short-term risk to organisms in the waters studied at the time of sampling. However, the detection of common UV filters, such as 4MBC, EHMC, OC and the common preservatives 2-PE, MP, and PB in these Victorian estuaries highlights that the existence of personal care products in the environment is not just an issue for more densley populated countries in the northern hemisphere, but also potentially of concern in Australia. And, in that context, more sampling campaigns in Port Philip Bay are of paramount importance to assess the potential risk posed by these compounds to aquatic ecosystems. [ABSTRACT FROM AUTHOR]

In the paper, the two chemically modified β-cyclodextrin derivatives of 4,4´-diaminodiphenyl ether-bridged-bis-β-cyclodextrins (ODA-bis-β-CD) and p-aminobenzenesulfonic acid-β-cyclodextrin (ABS-β-CD) were synthesized, and then these two β-cyclodextrin derivatives were respectively formed into inclusion complexes with benzophenone (BP) by co-precipitation method. The structure of the inclusion complexes were characterized by UV/vis spectroscopy, FT-IR spectroscopy, elemental analysis, 1H NMR spectroscopy and XRD. Spectral titration was performed to study the inclusion behavior of the inclusion complexes. These experiments indicated that two inclusion complexes were formed at a stoichiometric ratio of 1:1 and the inclusion stability constants at different temperatures were calculated using the Benesi-Hildebrand (B-H) equation. The thermodynamic parameters (ΔG°, ΔH°, ΔS°) were obtained. As a result, it was found that the two chemically modified β-cyclodextrins containing BP were exothermic and spontaneous process (ΔG° < 0), and the processes of inclusion complexation were mainly enthalpy driven with negative or minor negative entropic contribution. [ABSTRACT FROM AUTHOR]

This work reports the synthesis, protease inhibition, and antileishmanial activity of ten benzoxazole derivatives, which were obtained in a three-step synthetic route from 4-hydroxy-acetophenone and 4-hydroxy-benzophenone. These benzoxazoles, the synthetic intermediates, and the starting ketones were evaluated for their inhibitory effect on the activity of cysteine (papain, rCPB2.8, and rCPB3.0) and serine (trypsin) proteases. All compounds showed significant values of IC against these enzymes (in the range of 0.0086-0.7612 µM for papain and 0.0075-0.5032 µM for trypsin), being more active than the standard inhibitors (1.7821 and 7.2318 µM, for E64 and TLCK, respectively). Following, all compounds were evaluated in vitro for their leishmanicidal activity against promastigote form of Leishmania amazonensis. The most active compounds were further evaluated against amastigote form and for its toxicity against murine macrophages. The benzoxazole 4d, a benzophenone derivative, and the intermediate 4-hydroxy-3-nitroacetophenone 2b showed significant antileishmanial activity (IC = 90.3 µM and IC = 130.9 µM, respectively) with selectivity indexes (5.22 and 18.09, respectively) compared to or better than those of two established leishmanicidal drugs, pentamidine (0.58) and amphotericin B (5.31). Graphical Abstract: [ABSTRACT FROM AUTHOR]

Design and synthesis of five new derivatives of benzophenone based imidazole dyes is presented. Synthesized dyes were well characterized by H NMR, C NMR, FT-IR and mass analysis. Dyes contain a secondary acceptor, ESIPT core and different donors forming (D-ESIPT core-A) as basic skeleton in order to study both ESIPT and ICT systematically in this same class of dyes. Dyes without a donor substituent showed ESIPT emission while dyes with a substituted strong donor showed intramolecular charge transfer (ICT) emission. Moreover emission properties of methoxy analogue dyes has been studied to further confirm non-ESIPT emission in dyes without donors and ICT emission in strong donor substituted dyes. All dyes exhibited long range emissions from 392 to 567 nm. Dyes exhibiting ESIPT emission showed negative solvatochromism while ICT emission exhibiting dyes shows positive solvatochromism. ICT and ESIPT characteristics are well correlated with polarity functions plots and Mulliken-Hush analysis. Experimental observations are well supported by TD-DFT and computed energies. The electrophilicity index has been calculated to get details of the stabilities of possible tautomers. [ABSTRACT FROM AUTHOR]

A novel core-shell nanocomposite Ni-Ca@mSiO was first prepared by a modified Stöber method in this paper. It has a core-shell structure with Ni (about 8 nm in diameter) and Ca as the cores and mesoporous silica as the outer shell, as proven by the transmission electron microscopy. This nanocomposite exhibited good catalytic performance in the selective hydrogenation of benzophenone, with 96.1% conversion and 94.9% selectivity for benzhydrol under relatively mild reaction conditions. It was demonstrated that addition of small amounts of alkaline Ca can not only markedly improve the dispersion of the active species but also tune the acid-base property of this nanocomposite, resulting in the efficient suppression of benzhydrol dehydration to achieve a high selectivity. Furthermore, the core-shell nanocomposite Ni-Ca@mSiO can be recycled four runs without appreciable loss of its initial activity, more stable than the traditional supported nanocatalyst Ni-Ca/mSiO. It was suggested that the outer mesoporous silica shell of Ni-Ca@mSiO can prevent both the aggregation and the leaching of the active Ni species, accounting for its relatively good stability. [ABSTRACT FROM AUTHOR]

Mechanisms and elementary acts of the photoreduction of benzophenones with triethylamine, N,N-diethyl-p-toluidine, N,N-dimethylaniline, phenols, and aniline are identified from the effects of induced dynamic nuclear polarization (CIDNP). Benzophenone is photoreduced in either two stages (electron and then proton transfer) or one stage (hydrogen atom transfer). [ABSTRACT FROM AUTHOR]

Twenty-five benzophenone semicarbazones and thiosemicarbazones 3- 27 were synthesized starting from benzophenones via hydrazones treated with different aryl isocyanates and isothiocyantes under reflux. All synthetic derivatives were evaluated for their urease inhibitory potential. Good to moderate inhibition trend against urease was observed with the IC values in the range of 8.7-119.5 µM, when compared with the standard thiourea (IC = 21.2 ± 1.3 µM). Compound 15 showed better inhibition than the standard having the IC value of 8.7 ± 0.6 µM. Compounds 3, 4, 8, 11- 14, 16, and 17 with the IC values within the range of 26.1 to 43.6 µM, demonstrated good to moderate activities while compound 9 (IC = 119.5 ± 1.6 µM) displayed very weak activity. The enzyme kinetic studies on the most active compounds 15 and 17 were performed to deduce their modes of inhibition and dissociation constants K . [ABSTRACT FROM AUTHOR]

The spectral and luminescence properties of the heterogeneous two-component composite benzophenone-TiO -nanotubes (BP-NT) were studied in the temperature range 5-220 K. An analysis of the experimental data demonstrated that two structural modifications of benzophenone, amorphous and crystalline, existed simultaneously in the composite. The amorphous phase formed thin subsurface layers of benzophenone that were ~0.1-μm thick in BP-NT. This thickness in the BP-NT composite was less than that in a benzophenone-TiO -nanoparticle composite. It was found that triplet excitations were strongly quenched by the surface when the fi lm thickness became equal to the diffusion length of the triplet excitation. The results for the thin films and bulk benzophenone were compared. [ABSTRACT FROM AUTHOR]

The methanol extract from the fresh leaves of P. littorale was subjected to various column chromatography. This resulted in the isolation of four benzophenone glycoside derivatives: one new benzophenone glycoside, 2,6-dihydroxy-3-methyl-4-O- β-D-glucopyranosyl-benzophenone ( 1), one new diphenylmethane glycoside, 2,6-dihydroxy-3-methyl-4-O-(6″-O-galloyl- β-D-glucopyranosyl)-diphenylmethane ( 2), along with two known benzophenones, 2,6-dihydroxy-4-O- β-D-glucopyranosyl-benzophenone ( 3) and 2,6-dihydroxy-3-methyl-4-O-(6″-O-galloyl- β-D-glucopyranosyl)-benzophenone ( 4). Their structures were elucidated using data obtained from FAB-MS, H, and C NMR spectra and correlation experiments (HMQC and HMBC), as well as by comparison with published data. The activity of compounds 1-4 against five fungal species was investigated: the antimicrobial activity of all isolated compounds increased with concentration and varied according to the following rank: 1 ≥ 4 > 3 > 2, thereby showing some structure-activity relationships. [ABSTRACT FROM AUTHOR]

Aromatic esterificated benzophenone derivatives, benzoic acid 4-benzoyl-phenyl ester (BPBz) and bis-benzoic acid 4-benzoyl-phenyl ester (BisBPBz) were simply synthesized and characterized. The triplet states of the photoinitiators were determined by laser flash photolysis and phosphorescence spectroscopy. The photodecomposition of the initiators was performed by UV light; the increase in the absorption spectra was attributed to the decreasing number of ester groups which led to an increase in ketone groups according to the Photo-Fries rearrangement of aromatic esters. The photoinitiation capabilities for methyl methacrylate (MMA) polymerizations were investigated under air and nitrogen atmospheres. Ester-functional benzophenone photoinitiators were found to be more effective than benzophenone (BP) in the presence of a co-initiator for photoinduced free radical polymerization of MMA. The kinetics of photopolymerization for different formulations which consist of multifunctional acrylates was also studied using the Real-Time Fourier Transform infrared spectroscopy (RT-FTIR) method. The film properties of these formulations were investigated after curing of films by Mini-UV-Cure equipment. [ABSTRACT FROM AUTHOR]

Wet strengthening of paper products is typically performed by thermo-crosslinking reactive polymers or polymer precursors. In this article we introduce a novel concept for generating wet-strength paper grades by using photoreactive polymers and light as the energy source. Statistical, hydrophilic copolymers of dimethylacrylamide and benzophenone-methacrylate monomer, respectively, were synthesised and surface-applied to model paper handsheets. Benzophenone, as a photoreactive group, was selected because of its high crosslinking efficiency when illuminated with UV light (365 or 254 nm). After photo-crosslinking of the polymer-modified handsheets, first results of mechanical testing showed a significant increase of the wet tensile strength. The wet strength is a function of the molar content of the photoreactive group (benzophenone) within the polymer, the mass of the polymer relative to the dry fibre, the wavelength of irradiation and the intensity of UV exposure. Hence, there are a number of options to control and modulate the wet strength of paper sheets between less than 2 % (relative to the dry strength of the paper sheet) up to more than 15 %. In comparison to commercially available wet strength additives, crosslinking can be achieved even in the presence of humidity (up to 10 % water in the handsheet by weight) and at room temperature. [ABSTRACT FROM AUTHOR]

Photo-polymerization of the acrylate monomers, butylacrylate or 2-hydroxyethyl methacrylate, was initiated by polyurethane (PU) grafted benzophenone to prepare a series of urethane acrylate (UA) polymers. The UA polymers were characterized based on their thermal, spectroscopic, mechanical, and low temperature flexibility properties. In this system, poly(acrylate) chains grew from the grafted benzophenone by photo-polymerization and affected the molecular interactions between PU polymers. The soft segment glass transition temperature ( T) and melting temperature ( T) were unaffected by the grafted poly(acrylate) chains. The tensile mechanical strength and the tensile strain of the UA series increased significantly with the attachment of the poly(acrylate) chains. Furthermore, shape recovery and shape retention remained high as the test cycle was repeated. Low temperature flexibility testing demonstrated that the synthesized UA was more flexible at a lower temperature than the unmodified PU. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Optical brighteners are commonly used to modify the appearance and to improve polymer properties of packaging. They are not chemically bound to polymers and able to migrate from packaging into the foods. These migrants are potentially harmful to human health. In concern with human safety an approach was made to analyze three optical brighteners such as diphenylbutadiene, Uvitex-OB, benzophenone in commercial fruit juice and jam. The migration level of these optical brighteners from low density poly ethylene packaging into fruit juice and jam was studied. Two optimized and validated analytical techniques such as spectrofluorimetry and high performance liquid chromatography with photo diode array detector used for migration study. Both methods have shown high correlation coefficients (>0.999), over a concentration range of 0.1-3.2 μg/mL, 0.1-1 μg/mL, 0.05-3.2 μg/mL for diphenylbutadiene, Uvitex-OB and benzophenone respectively. The preliminary studies confirm that the low density poly ethylene layer taken for study contained of diphenylbutadiene and the other two were absent. The migration level of diphenylbutadiene was studied at room temperature and different elevated temperature from 30 °C to 60 °C for up to 3 weeks. At room temperature no migration of diphenylbutadiene was observed where as at higher temperature migration could be observed. The maximum quantity of diphenylbutadiene migrated was found to be 0.0462 mg/kg from tetrapak, and 0.0382 mg/kg from jam squeeze after 3 weeks treatment at 60 °C. The migration of diphenylbutadiene was found to be less than allowable concentration during the study period. [ABSTRACT FROM AUTHOR]

This study describes a procedure for determining eight benzophenone-derived compounds in surface waters and sediments. These include the pharmaceutical ketoprofen, its phototransformation products 3-ethylbenzophenone and 3-acetylbenzophenone, and five benzophenone-type ultraviolet (UV) filters. The proposed analytical method involves the pre-concentration of water samples by solid-phase extraction (SPE) and microwave-assisted extraction (MAE) of sediment samples followed by derivatization and analysis by gas chromatography-mass spectrometry. Different parameters were investigated to achieve optimal method performance. Recoveries of 91 to 96 % from water samples were obtained using HLB Oasis SPE cartridges, whereas MAE of sediments (30 min at 150 °C) gave recoveries of 80 to 99 %. Limits of detection were between 0.1 and 1.9 ng L for water samples and from 0.1 to 1.4 ng g for sediment samples. The developed method was applied to environmental samples and revealed the presence of UV filters in the majority of the surface waters with up to 690 ng L of 2-hydroxy-4-methoxybenzophenone. By contrast, ketoprofen (≤2,900 ng L) and its degradation products (≤320 ng L) were found in only two rivers, both receiving wastewater treatment plant effluents. Sediment analysis revealed benzophenone to be present in concentrations up to 650 ng g, whereas concentrations of other compounds were considerably lower (≤32 ng L). For the first time, quantifiable amounts of two ketoprofen transformation products in the aqueous environment are reported. [ABSTRACT FROM AUTHOR]

2,5-Disubstituted 1,3,4-oxadiazole compounds are one of the most attractive heterocyclic compounds for researchers due to their biological activities. In the undertaken research, a number of potential 2,5-disubstituted 1,3,4-oxadiazole analogues were synthesized through multi step reaction and characterized by FT-IR, H NMR, mass spectra, and also by elemental analysis. Further benzophenone tagged indole acetohydrazides and 2,5-disubstituted 1,3,4-oxadiazoles were evaluated for antioxidant potential, through different in vitro models such as DPPH, nitric oxide and hydrogen peroxide methods. In the series of compounds some of them had shown good to moderate in vitro antioxidant potential compare to the standard drug ascorbic acid in all the above three methods. [ABSTRACT FROM AUTHOR]

We introduce a novel approach for preparing polymer-modified and chemically microstructured paper substrates by a photo-chemical attachment of functional polymers to cellulose microfibers inside model filter papers. Poly(methyl methacrylate), PMMA copolymers, which carry a defined amount of photo-reactive benzophenone functional groups, are adsorbed to paper substrates from solution by a simple dip coating process, followed by covalent attachment of the physisorbed polymers through UV-light irradiation. Non-bound macromolecules can be removed from paper sheets by simple solvent extraction, and the resulting polymer-modified substrates were analysed with respect to chemical identity, attached polymer mass, and homogeneity of the polymer attachment. The amount of paper-attached polymers can be conveniently controlled in a wide range from a few mg/g cellulose fiber up to several tenth of mg/g cellulose fiber, by adjusting the polymer concentration in the coating solution. Polymers are being attached by photo-chemical means, and chemical micro patterns on paper can be designed by lithographical means. In first proof-of-concept studies, millimeter-scale channels were prepared that can be used to control fluid penetration by capillary actions. Because of the modularity in the design of photo-reactive polymers, a number of different chemically microstructured papers can be envisioned which may become potentially interesting in lab-on-paper devices. [ABSTRACT FROM AUTHOR]

The synthesis of photosensitive urethane dimethacrylate that contains poly(ethylene oxide) sequence (PEG, M: 400), carboxylic and benzophenone moieties, and its characterization by specific methods (H and C NMR, FTIR, UV and electrospray ionization-mass spectroscopy) are reported. UV curing parameters of this macromer (BP-UDMA) alone and in monomer combinations was evaluated through FTIR spectroscopy and photo-differential scanning calorimetry using 1 wt% 4-(dimethylamino)phenylacetic acid as co-initiator or Irgacure 819 (Irg819). The results show that the photopolymerization rates of the BP-UDMA are higher in the case of Irg819 (R: 0.108 s) due to its synergic action, whereas the degree of conversion of C=C double bond (DC, after 120 s of UV irradiation) is over 77 %. When other co-monomers (non-acid urethane dimethacrylate and silyl urea methacrylate) are incorporated into the formulation, the photopolymerization rate (0.095-0.132 s) and DC (84.59-79.69 %) varied in reasonable limits. Depending of the photoinitiator type, as well as the monomer composition, the addition of 0.5, 1 and 3 wt% noble metal precursors (AgNO and AuBr) led to the formation of hybrid composites with in situ-synthesized nanoparticles (NPs), where the variations in the intensity of the surface plasmon absorption bands appeared in the range 400-456 nm (Silver) or 500-553 nm (Gold), better results being obtained in the first initiating system. Homogeneous dispersion of nanoparticles into the polymer matrix was evidenced by EDX and TEM analysis, the last proving the existence of nanoparticles with sizes around 10 nm and variable morphologies. X-ray diffraction analysis complemented these results. [ABSTRACT FROM AUTHOR]

Mesoporous spherical Si-MCM-41 and V-MCM-41 materials with a variable Si/V ratio of 25, 50, 75 and 100 were prepared by an economical route at room temperature and characterized by various techniques for qualitative and quantitative understanding of vanadium species. The morphology and mesoporosity of the spherical particles were confirmed by SEM and TEM micrographs. The catalytic activity of the synthesized catalysts was tested for vapour phase oxidation of diphenylmethane to benzophenone using CO free air as oxidant at atmospheric pressure. The conversion of diphenylmethane and selectivity for benzophenone were measured in the temperature range of 593-713 K over V-MCM-41 catalysts synthesized by adopting room temperature method as well as by direct hydrothermal method. The catalytic performance was related to vanadium content on the surface of the catalysts. [ABSTRACT FROM AUTHOR]

The purification of the acetone extract from the inflorescences of Garcinia cowa led to the isolation of a new benzophenone derivative, cowanone ( 1), together with seven known xanthones, α-mangostin ( 2), β-mangostin ( 3), cowanin ( 4), fuscaxanthone A ( 5), 9-hydroxycalabaxanthone ( 6), garcinianone A ( 7) and cowanol ( 8). The structures of the isolated compounds were elucidated by analysis of their spectroscopic data including 1D and 2D NMR data. All isolated compounds were evaluated for their antibacterial activities against Staphylococcus aureus (SA) and methicillin-resistant S. aureus (MRSA). [ABSTRACT FROM AUTHOR]

Lycopene antioxidant activity in the presence of two different mixtures of phospholipids in hexane solution, under continuous regime of UV-irradiation from three different ranges (UV-A, UV-B, and UV-C) has been evaluated in this work. Lycopene expected role was to control lipid peroxidation, by scavenging free radicals generated by UV-irradiation, in the presence and in the absence of selected photosensitizer, benzophenone. This work shows that lycopene undergoes to UV-induced destruction (bleaching), highly dependent on the incident photons energy input, more expressed in the presence than in the absence of benzophenone. The further increase ('excess') of its bleaching is undoubtedly related to the further increase of its antioxidant activity in the presence of benzophenone, having the same cause: increase of (phospholipids peroxidation) chain-breaking activities. [ABSTRACT FROM AUTHOR]

Photochemical processes of benzophenone (BP) and xanthone (XT) with tryptophan (TrpH) and tyrosine (TyrOH) were studied using the laser flash photolysis technique. It has been observed that the triplet state of BP and XT reacted with TrpH and TyrOH by hydrogen transfer with the formation of BP and XT ketyl radicals and oxidized radicals of Trp· and TyrO·. The related rate constants of these reactions were determined in this paper. The free energy changes (Δ G) of these reactions suggested that the proposed hydrogen transfer mechanism was thermodynamically feasible. These results provide theoretical foundation for further studying structural effects on the photochemical behaviors of proteins with triplet state BP and XT. [ABSTRACT FROM AUTHOR]

The mesoporous vanadium oxide (MVO) was prepared from the surfactant cetyltrimethylammonium bromide along with benzyl alcohol as co-surfactant. It was found that the presence of benzyl alcohol in the synthetic mixture was essential to the formation and stability of MVO material. Characteristic mesoporous structure with uniform channel spacing as well as large surface area and pore volume of MVO sample were identified by XRD, SEM, TEM, and N sorption techniques. The structure of vanadium-oxygen framework was explored using FT-IR and V MAS NMR spectroscopy; the MVO sample possessed distorted tetrahedron structure. Results from TPR studies indicated the easier reducibility of MVO as compared to bulk VO. In the liquid-phase selective oxidation of diphenylmethane to benzophenone in acetic acid as solvent, the MVO catalyst exhibited remarkably better catalytic performance than bulk VO; at 60 °C, the conversion and benzophenone selectivity reached 39.6 and 96.7% after 1 h reaction time, with a catalyst turnover frequency of 24.2 h. These superior results were properly correlated to the physico-chemical properties of MVO catalyst. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to determine the effect of photosensitive groups contained in the main chain of polymeric photoinitiator on photopolymerization. Through polycondensation of toluene-2,4-diisocyanate (TDI), different diamines and N-phenyldiethanolamine (PDEA), three novel polymeric photoinitiators containing in-chain benzophenone (BP) and coinitiator amine were synthesized in comparison with the corresponding side-chain ones. FT-IR, H NMR and GPC analyses confirm the structures of all polymers. UV-Vis spectra showed that the maximal absorption and the molar extinction coefficient of polymeric photoinitiator can be greatly improved by the electron donating groups and the imino nitrogen that directly link to BP structure. The photopolymerization of trimethylolpropane triacrylate (TMPTA) and PU prepolymer, initiated by these polymeric photoinitiators, was studied by photo-DSC. The results indicate that the location of photosensitive group has an important effect on the photoefficiency of polymeric photoinitiators. The efficiency order of polymeric photoinitiators comprising in-chain BP is different from that of the side-chain ones: PUIBA-s and PUIBA-n are the most efficient for TMPTA and PU prepolymer, respectively. [ABSTRACT FROM AUTHOR]

This paper reports a simple effective way to photochemically attach a polyelectrolyte layer to an electrode substrate. The system is based on photoreactive benzophenone (BP)-containing copolymers that are bound to alumina surfaces via an alkoxysilane coupling reaction. The alumina substrate was then covered with a BP film that can be reacted with the polyelectrolyte by irradiation with UV light. As a result of the photochemical reaction, the polyelectrolyte was bound covalently to the electrode surfaces. As an example, a thin layer of copolymer of [2-(acryloyloxy)ethyl]trimethyl ammonium chloride (AETAC), styrene (ST), 2-hydroxyethylacrylate (HEA), and 4-acryloxybenzophenone (BPA) (AETAC/ST/HEA/BPA=60/33/4/3) was attached successfully. A pretreatment of the substrate with BP-containing polymeric silane-coupling reagents, AETAC/3-(trimethoxysilyl)propyl methacrylate (TMSPM)/HEA/BPA=50/30/10/10 or TMSPM/HEA/BPA=50/25/25, was performed to improve the water durability and stability at high temperatures and humidity. Their water durability, high temperature/humidity stabilities and long-term stability were evaluated to confirm their usefulness as a humidity-sensing polyelectrolyte membrane. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The interaction between benzophenone (BP) and bovine serum albumin (BSA) was investigated by the methods of fluorescence spectroscopy combined with UV-Vis absorption and circular dichroism (CD) measurements under simulative physiological conditions. The experiment results showed that the fluorescence quenching of BSA by BP was resulted from the formation of a BP-BSA complex and the corresponding association constants ( K) between BP and BSA at four different temperatures had been determined using the modified Stern-Volmer equation. The enthalpy change (Δ H) and entropy change (Δ S) were calculated to be -43.73 kJ mol and −53.05 J mol K, respectively, which suggested that hydrogen bond and van der Waals force played major roles in stabilizing the BP-BSA complex. Site marker competitive experiments indicated that the binding of BP to BSA primarily took place in site I (sub-domain IIA). The conformational investigation showed that the presence of BP decreased the α-helical content of BSA and induced the slight unfolding of the polypeptides of protein, which confirmed some micro-environmental and conformational changes of BSA molecules. [ABSTRACT FROM AUTHOR]

This paper describes a new fluorescent family of branched dyes containing benzophenone unit including 4-N, N-diphenylamino- 4′-phenacyl-stilbene ( C1), 4,4′-di(4-benzoylphenylethylene)yl-triphenylamine ( C2) and 4,4′,4″-tri(4-benzoylphenylethylene)yl-triphenylamine ( C3). Benzophenone part is coupled with core through C-C double bond. The chemical structures of the derivatives are characterized with H and C nuclear magnetic resonance and elemental analysis. Strong π-π stacking interactions are discovered with the analysis of the X-ray crystallographic data of C1. The absorption maxima and emission maxima of the derivatives exhibit gradual bathochromic shift from C1 to C3. The optical density of C1, C2 and C3 are shown to be related to the number of branches. The changes of dipole moments between the excited and ground states for C1, C2 and C3 were estimated to be 4.356, 8.091 and 8.479 Derby, respectively by Lippert equation, confirming that the internal charge transfer (ICT) dominates the process of excited singlet state. The possibility as fluorescence probes of the derivatives on the estimation of what region of micelles interacting with samples was evaluated. [ABSTRACT FROM AUTHOR]