P-aminobenzoic acid promotes retinal regeneration through activation of Ascl1a in zebrafish

The retina of zebrafish can regenerate completely after injury.M ultiple studies have demonstrated that metabolic alte rations occur during retinal damage;however to date no study has identified a link between metabolites and retinal regeneration of zebrafish.Here,we performed an unbiased metabolome sequencing in the N-methyl-D-aspartic acid-damaged retinas of zebrafish to demonstrate the metabolomic mechanism of retinal regeneration.Among the differentially-ex pressed metabolites,we found a significant decrease in p-aminobenzoic acid in the N-methyl-D-aspartic acid-damaged retinas of zebrafish.Then,we investigated the role of p-aminobenzoic acid in retinal regeneration in adult zebrafish.Impo rtantly,p-aminobenzoic acid activated Achaetescute complex-like 1a expression,thereby promoting Müller glia reprogramming and division,as well as Müller glia-derived progenitor cell proliferation.Finally,we eliminated folic acid and inflammation as downstream effectors of PABA and demonstrated that PABA had little effect on Müller glia distribution.Taken together,these findings show that PABA contributes to retinal regeneration through activation of Achaetescute complex-like 1a expression in the N-methyl-Daspartic acid-damaged retinas of zebrafish.

Ag-Ni alloy nanoparticles for electrocatalytic reduction of benzyl chloride

Ag-based nanocatalysts exhibit good catalytic activity for the electrochemical reduction of organic halides. Ag-Ni alloy nanoparticles（NPs） were facilely prepared by chemical reduction, and the as-prepared nanocatalysts were characterized by X-ray diffraction, ultraviolet-visible spectroscopy, transmission electron microscopy and energy-dispersive X-ray spectroscopy. The electrocatalytic activity of Ag-Ni NPs for benzyl chloride reduction was studied in organic medium using cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The results show that the addition of Ni element can obviously decrease the size of Ag-Ni NPs, shift the reduction peak potential（φp） of benzyl chloride positively, and increase the catalytic activity of Ag-Ni NPs. However, when the Ni content reaches a certain value, the catalytic activity of Ag-Ni NPs decreases. Meanwhile, the synergistic catalytic effect of Ag-Ni NPs was also discussed.

Content determination of benzyl glucosinolate and anti—cancer activity of its hydrolysis product in Carica papaya L.

Objective:To determine the content of benzyl glueosinolate（BG） in the pulp and the seed and investigate the anti-cuncer activity of its hydrolysis product in Curica papaya L.Methods: Determination of BG was performed on an Hypersil BDS C18 column at the wavelength of 214 nm with 0.1%trifluoroacelic acid（TFA） aqueous solution（A） and 0.1%TFA acelonilrile（B） as the mobile phase.In vitro activity test was adopted with cidtured human lung cancer H69 cell in vitro to investigate the inhibition rate of cell proliferation of benzyl isothiocyanale（BITC） againsl H69 cell.Results:The pulp has more BG before the maturation of papaya and it nearly disappeared after papaya matured,while the seed contains BG at every stage.Activity test demonstrated that the a higher concentration of BITC would have betler inhibition rate of cell proliferation on 1169 cell,and the IC50 was 6.5μmol/L.Conclusions:BG also can be produced in the pulp of papaya and it will be stored in the seed after the fruit has been matured.The hydrolysis product of BG has certain cancer-prevention anti-cancer activities for human.

Highly efficient and selective photocatalytic dehydrogenation of benzyl alcohol for simultaneous hydrogen and benzaldehyde production over Ni-decorated Zn_(0.5)Cd_(0.5)S solid solution

Photocatalytic conversion of solar energy into hydrogen and high value-added fine chemicals has attracted increasing attention. Herein, we demonstrate an efficient photocatalytic system for simultaneous hydrogen evolution and benzaldehyde production by dehydrogenation of benzyl alcohol over Nidecorated Zn_(0.5)Cd_(0.5)S solid solution under visible light. The photocatalytic system shows an excellent hydrogen production rate of 666.3 μmol h^(-1) with high stability. The optimal apparent quantum yield of52.5% is obtained at 420 nm. This noble-metal-free photocatalytic system displays much higher activity than pure Zn_(0.5)Cd_(0.5)S and Pt-loaded Zn_(0.5)Cd_(0.5)S solid solution. Further studies reveal that the metallic Ni nanocrystals play an important role in accelerating the separation of photogenerated charge carriers and the subsequent cleavage of α-C–H bond during dehydrogenation of benzyl alcohol.

Synthesis of Pharmaceutical Intermediates by Toluene Benzylation over Heteropoly Acids on Different Support

Selective formation of pharmaceutical intermediates like diphenylmethane, dimethyldiphenylmethane, benzyl toluene and benzoic acid by liquid phase, toluene benzylation with benzyl chloride as a benzylating agent, was systematically studied over plane clay （K-10, montmorillonite）, plane H-Beta, plane MFI structured titanosilicate （TS-1） and heteropoly acids [HPA, namely dodecatungstophosphoric acid [H3PO4.12WOa-xH2O] （TPA）, dodeca-molybdo phosphoric acid ammonium salt hydrate [H12Mo12N3040P＋aq] （DMAA）, sodium tungstate hydrated purified [Na12WO4.2H2O] （STH）] supported on clay, H-beta and TS-1. The 20%TPA/Clay, 30%TPA/H-Beta and 30%TPA/TS-1, were observed to be the best catalyst samples over plane clay, plane H-Beta and plane TS-1. The catalyst samples are compared with respect to benzyl chloride conversion and selectivities for diphenylmethane, dimethyl-diphenylmethane, benzyl toluene and benzoic acid. The reaction follows the pseudo-first order rate power law model. The apparent rate constants are calculated and compared with the reported ones.

Efficient oxidation of benzyl alcohol with heteropolytungstate as reaction-controlled phase-transfer catalyst

A series of heteropolytungstates has been synthesized and utilized as catalysts to catalyze oxidation of benzyl alcohol with aqueous hydrogen peroxide. The results indicated that three of these catalysts showed the properties of reaction-controlled phasetransfer catalysis, and they had excellent catalytic ability to the oxidation of benzyl alcohol. No other by-products were detected by gas chromatography. Once the hydrogen peroxide was consumed completely, the catalyst precipitated from solvent, and the results of the catalyst recycle showed that the catalyst had high stability.

Aerobic Oxidation of Benzyl Alcohol Catalyzed by Cu-Mn Mixed Oxides and 2,2,6,6-Tetramethyl-piperidyl-1-oxyl

Heterogeneous Cu-Mn mixed oxides can mediate TEMPO-catalyzed selective oxidation of benzyl alcohol by molecular oxygen under neutral condition, and is recyclable. In the case of the molar ratio of Cu and Mn over 1, the highly-dispersed CuO inside the Cu-Mn mixed oxides is responsible for the good performances in catalytic oxidation.

The Role of Vanadia for the Selective Oxidation of Benzyl Alcohol over Heteropolymolybdate Supported on Alumina

A series of 12-molybdophosphoric acid (MPA) supported on V2O5 dispersed γ-Al2O3 catalysts with different vanadia loadings were prepared by impregnation and characterized by N2 adsorption-desorption, X-ray diffraction, temperature-programmed reduction, in situ laser Raman spectroscopy, UV-Vis diffused reflectance spectroscopy, scanning electron microscopy, and temperature-programmed desorption of NH3 techniques. Their catalytic activities were evaluated for the vapor phase aerobic oxidation of benzyl alcohol. The catalysts exhibited high catalytic activity and the conversion of benzyl alcohol depended on the vanadia content while the catalyst with 15 wt% V2O5 content showed optimum activity. The characterization results suggest the presence of well-dispersed V2O5 and partially disintegrated Keggin ions of MPA on the support. In situ Raman studies showed a reduced Mo(IV) species when the catalysts were calcined at high temperatures. The high oxidation activity of the catalysts is related to the synergistic effect between MPA and V2O5.

Two Benzyl Dihydroflavones from Phellinus igniarius

Two new benzyl dihydroflavones phelligrins A and B were isolated from the fruit body of Phellinus igniarius. Their structrues were identified as 5, 7, 4-trihydroxy-6-O-hydroxybenzyl -dihydroflavone and 5, 7, 4-trihydroxy-8-O-hydroxybenzyldihydroflavone, respectively, by means of spectral methods.

Catalytic Performance of MnOx Nanorods in Aerobic Oxidation of Benzyl Alcohol

Various manganese oxide nanorods with similar one-dimensional morphology were prepared by calcination of MnOOH nanorods under different gas atmosphere and at different temper- atures, which were synthesized by a hydrothermal route. The morphology and structure of MnOx catalysts were characterized by a series of techniques including X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and tempera- ture programmed reduction （TPR）. The catalytic activities of the prepared MnO~ nanorods were tested in the liquid phase aerobic oxidation of benzyl alcohol, which follow a sequence as MnO2〉Mn203~Mn304〉MnOOH with benzaldehyde being the main product. On the basis of H2-TPR results, the superior activity of MnO2 is ascribed to its lower reduction temperature and therefore high oxygen mobility and excellent redox ability. Moreover, a good recycling ability was observed over MnO2 catalysts by simply thermal treatment in air.

Investigation of benzylisoquinoline alkaloid biosynthetic pathway and its transcriptional regulation in lotus

Lotus predominantly accumulates benzylisoquinoline alkaloids(BIAs),but their biosynthesis and regulation remain unclear.Here,we investigated structural and regulatory genes involved in BIA accumulation in lotus.Two clustered CYP80 genes were identified to be responsible for the biosynthesis of bis-BIAs and aporphine-type BIAs,respectively,and their tissue-specific expression causes divergence in alkaloid component between leaf and embryo.In contrast with the common(S)-reticuline precursor for most BIAs,aporphine alkaloids in lotus leaf may result from the(S)-N-methylcoclaurine precursor.Structural diversity of BIA alkaloids in the leaf is attributed to enzymatic modifications,including intramolecular C–C phenol coupling on ring A and methylation and demethylation at certain positions.Additionally,most BIA biosynthetic pathway genes show higher levels of expression in the leaf of high-BIA cultivar compared with low-BIA cultivar,suggesting transcriptional regulation of BIA accumulation in lotus.Five transcription factors,including three MYBs,one ethylene-responsive factor,and one basic helix–loop–helix(bHLH),were identified to be candidate regulators of BIA biosynthesis in lotus.Our study reveals a BIA biosynthetic pathway and its transcriptional regulation in lotus,which will enable a deeper understanding of BIA biosynthesis in plants.

Selective debenzylation of benzyl esters by silica-supported sodium hydrogen sulphate

A new debenzylation of benzyl esters by silica-supported sodium hydrogen sulfate is described. The debenzylation could be achieved selectively and efficiently in good to excellent yields without affecting sensitive functional groups such as nitro, unsaturated bonds, and ethyl ester.

Aerobic oxidation of benzylic aldehydes to acids catalyzed by iron (Ⅲ) meso-tetraphenylporphyrin chloride under ambient conditions

Highly efficient aerobic oxidation of benzylic aldehydes to the corresponding acids catalyzed by iron （Ⅲ） meso-tetrapbenylporphyrin chloride （Fe（TPP）Cl） under ambient conditions was developed. The catalyst has been proved to be an excellent catalyst for the system in the presence of molecular oxygen and isobutryaldehyde at room temperature.

Photocatalytic oxidation of primary and secondary benzyl alcohol catalyzed by two coenzyme NAD^+ models

Photocatalytic oxidation of primary and secondary benzyl alcohol to corresponding benzaldehyde or acetophenone using Acr＋Cl04- or PhAcr＋Cl04- as photocatalysts under visible light irradiation at room temperature.

Template-free synthesis of hollow TiO2 nanospheres supported Pt for selective photocatalytic oxidation of benzyl alcohol to benzaldehyde

Heterogeneous photocatalytic system are widely applied to degrade organic pollutants or converse into high value-added chemicals. Both environmental and energy aspects should be considered to improve these chemical processes, favoring reaction conditions that involve room temperature and ambient O2 pressure. In the present work, hollow titanium dioxide nanospheres were fabricated via template-free method. The prepared samples were characterized by X-ray diffraction, N2 adsorption–desorption isotherms, transmission electron microscopy, and X-ray photoelectron spectroscopy. The photocatalytic activity was evaluated by photocatalytic oxidation of benzyl alcohol to benzaldehyde with visible light under atmospheric pressure at room temperature. The designed hollow structure(2%Pt–TiO2–5) not only exhibited a very high surface area,but also promoted photonic behavior and multiple light scattering, which as an efficient photocatalyst performed moderate conversion(about 20%) and high selectivity(> 99%) for oxidation of benzyl alcohol to benzaldehyde at room temperature with visible light in solvent of toluene.This work suggests that both hollow structure and Pt nanoparticles have great potential for execution of oxidative transformations under visible light.

Hydrogenation of Alkenes with NaBH4, CH3CO2H, Pd/C in the Presence of O- and N-Benzyl Functions

NaBH4, CH3CO2H, Pd/C has been described as an effective reagent system to hydrogenate alkenes. Here, we show that the hydrogenation occurs chemoselectively, making it possible to hydrogenate alkenes under Pd/C catalysis with hydrogen created in situ without O- or N-debenzylation.

SIDE CHAIN LIQUID CRYSTALLINE POLYSILOXANES CONTAINING CROWN ETHER AND BENZYL ETHER MOIETIES

Two kinds of side chain liquid crystalline polysiloxanes containing crown ether and benzyl ether were synthesized and characterized by optical polarization microscopy. Both the monomeric liquid crystals and polymeric liquid crystals show smectic phases.

Genome and transcriptome of Papaver somniferum Chinese landrace CHM indicates that massive genome expansion contributes to high benzylisoquinoline alkaloid biosynthesis

Opium poppy(Papaver somniferum)is a source of morphine,codeine,and semisynthetic derivatives,including oxycodone and naltrexone.Here,we report the de novo assembly and genomic analysis of P.somniferum traditional landrace‘Chinese Herbal Medicine’.Variations between the 2.62 Gb CHM genome and that of the previously sequenced high noscapine 1(HN1)variety were also explored.Among 79,668 protein-coding genes,we functionally annotated 88.9%,compared to 68.8%reported in the HN1 genome.Gene family and 4DTv comparative analyses with three other Papaveraceae species revealed that opium poppy underwent two whole-genome duplication(WGD)events.The first of these,in ancestral Ranunculales,expanded gene families related to characteristic secondary metabolite production and disease resistance.The more recent species-specific WGD mediated by transposable elements resulted in massive genome expansion.Genes carrying structural variations and large-effect variants associated with agronomically different phenotypes between CHM and HN1 that were identified through our transcriptomic comparison of multiple organs and developmental stages can enable the development of new varieties.These genomic and transcriptomic analyses will provide a valuable resource that informs future basic and agricultural studies of the opium poppy.

Modification of pillared MFI zeolite nanosheets by nitridation with tailored activity in benzylation of mesitylene and benzyl alcohol

The modification of pillared MFI zeolites was performed by nitridation of silica pillared MFI zeolite nanosheets under NH3 atmosphere with different time. The resultant zeolites were characterized by a complementary combination of X-ray power diffraction(XRD), scanning electron microscopy(SEM),transmission electron microscopy(TEM), pyridine-IR spectroscopy and N2 adsorption–desorption isotherms. The analyses showed that the nitridation didn’t destroy the crystallinity and specific surface area of zeolites, and the acidity of zeolites can be tailored by tuning the time of nitridation, resulting in the different concentration ratios of Br?nsted-to-Lewis(B/L) acid sites. Moreover, the nitrided zeolites exhibited high selectivity to 2-benzyl-1,3,5-trimethylbenzene than parent silica pillared MFI zeolite nanosheets in benzylation of mesitylene with benzyl alcohol. A balance between Br?nsted acid sites and Lewis acid sites can inhibit the self-etherification of benzyl alcohol and enhance the selectivity of alkylated product. These experimental data implied that nitridation was an effective method to modulate the acidity of zeolites and the synergy between Br?nsted acid sites and Lewis acid sites was a decisive factor to determine the selectivity.

Studies of benzyl hydroxamic acid/calcium lignosulphonate addition order in the flotation separation of smithsonite from calcite

Flotation separation of smithsonite from calcite is difficult due to their similar surface properties.In the present study,a reagent scheme of depressant calcium lignosulphonate(CLS) and collector benzyl hydroxamic acid(BHA) was introduced in the flotation of smithsonite from calcite.Microflotation tests revealed that the efficient flotation of smithsonite from calcite could only be obtained with the addition order of BHA before CLS,which was opposite to the widely-used order that adding depressant prior to the collector.The zeta potential measurements indicated that BHA selectively adsorbed onto smithsonite surface,then not allowed the CLS adsorption onto the smithsonite surface rather than calcite surface because of the steric hindrance,thereby the smithsonite surface remained hydrophobic while calcite surface became more hydrophilic after the addition of CLS.As a result,the calcite flotation was completely depressed while the smithsonite flotation recovery was still in high value,leading to the optimal flotation separation performance.