Benzalacetone Research Articles

Additive effects on tin electrodepositing in acid sulfate electrolytes

The effects of additives on the stannous reduction of an acid sulfate bath were investigated using cyclic and linear sweep voltammetry, electrochemical impedance spectroscopy (EIS), and microstructure analysis. In the absence of additives, tin coatings are rough, and the tin electrodepositing is a single-step reduction process accompanied by hydrogen gas evolution. The addition of tartaric acid produces a slight reduction in the peak current of stannous reduction and has an appreciably positive effect on the stability of the acidic tin bath. Both benzylidene acetone and polyoxyethylene octylphenol ether hinder the stannous reduction and greatly suppress the hydrogen gas evolution. Formaldehyde slightly decreases the peak current density of stannous reduction and serves as an auxiliary brightener in the acid sulfate bath. The presence of mixed additives greatly suppresses the stannous reduction and hydrogen gas evolution and consequently produces a significantly smoother and denser tin coating. The (112) crystal face is found to be the dominant and preferred orientation of tin deposits.

ChemInform Abstract: Synthesis of α‐Aryl Enaminones Through Reactions of β‐Aryl Enones with Benzyl Azide.

AbstractThe BF3·OEt2‐promoted reaction of benzalacetones and dibenzalacetones with azide (II) is investigated.

ChemInform Abstract: Carbo[3 + 3] Cyclocondensation Reactions. A New Method for the Synthesis of Tetrahydropyrazolo[1,5‐b]quinazolines and Tetrahydropyrazolo[4,5‐b]quinolines.

The cyclocondensation of substituted 5-aminopyrazoles with benzylidene acetone leads to the regioselective synthesis of dihydropyrazolo[1,5-a]pyrimidines and dihydropyrazolo[3,4-b]pyridines containing a methyl group in the six-membered heterocycle. Compounds of both these groups readily undergo carbo[3 + 3] cyclo-condensation with chalcones in butanol under alkaline catalysis conditions and upon heating to give aryl-substituted tetrahydropyrazolo[1,5-b]quinazolines and tetrahydropyrazolo[4,5-b]quinolines. Ultrasonic initiation of these reactions leads to enhanced rate and higher yield of the desired products.

Gas chromatography with flame ionization detection for determination of additives in an electrolytic Zn bath

The monitoring of additives in electrolytic baths is a fundamental task for proper coatings. Among the additives used in zinc baths, benzylideneacetone (BDA), benzoic acid (BA) and polyethylene glycol 400 (PEG400) are easily found. This paper deals with the possibilities of handling the bath sample before it is taken to a gas chromatograph (GC) in order to follow the additives concentration along the bath life. The applied techniques include solid phase extraction (SPE), solvent extraction (SE), static headspace (SHS), direct injection (DI) and headspace solid phase microextraction (HS-SPME) recoveries up to 6:1, 14:1, 9:1, 1:1 and 80:1 respectively have been obtained. Internal standards have been found for every case. Advantages and disadvantages of the techniques are collected. In this paper DI and HS-SPME have finally been applied, though none of them is able for PEG400 determination. DI provides quantitative information for BA (limit of detection, LOD, 1.6gL−1) and BDA (LOD, 0.09gL−1); HS-SPME only provides quantitative information for BDA (LOD, 0.05gL−1). Taking into account that PEG400 and BA do not practically change with the use of the bath, that DI is very quick and simple and that no significant differences with spectrophotometric results have been found, DI is recommended for the monitoring of BA and BDA along the zinc bath life. This should be considered a technique for process analysis for these additives.

Carbo[3 + 3] cyclocondensation reactions. A new method for the synthesis of tetrahydropyrazolo[1,5-b]quinazolines and tetrahydropyrazolo[4,5-b]quinolines

The cyclocondensation of substituted 5-aminopyrazoles with benzylidene acetone leads to the regioselective synthesis of dihydropyrazolo[1,5-a]pyrimidines and dihydropyrazolo[3,4-b]pyridines containing a methyl group in the six-membered heterocycle. Compounds of both these groups readily undergo carbo[3 + 3] cyclo-condensation with chalcones in butanol under alkaline catalysis conditions and upon heating to give aryl-substituted tetrahydropyrazolo[1,5-b]quinazolines and tetrahydropyrazolo[4,5-b]quinolines. Ultrasonic initiation of these reactions leads to enhanced rate and higher yield of the desired products.

Mechanistic Insights on the Hydrogenation of α,β-Unsaturated Ketones and Aldehydes to Unsaturated Alcohols over Metal Catalysts

The selective hydrogenation of unsaturated ketones (methyl vinyl ketone and benzalacetone) and unsaturated aldehydes (crotonaldehyde and cinnamaldehyde) was carried out with H2 at 2 bar absolute over Pd/C, Pt/C, Ru/C, Au/C, Au/TiO2, or Au/Fe2O3 catalysts in ethanol or water solvent at 333 K. Comparison of the turnover frequencies revealed Pd/C to be the most active hydrogenation catalyst, but the catalyst failed to produce unsaturated alcohols, indicating hydrogenation of the C═C bond was highly preferred over the C═O bond on Pd. The Pt and Ru catalysts were able to produce unsaturated alcohols from unsaturated aldehydes, but not from unsaturated ketones. Although Au/Fe2O3 was able to partially hydrogenate unsaturated ketones to unsaturated alcohols, the overall hydrogenation rate over gold was the lowest of all of the metals examined. First-principles density functional theory calculations were therefore used to explore the reactivity trends of methyl vinyl ketone (MVK) and benzalacetone (BA) hydrogenation over model Pt(111) and Ru(0001) surfaces. The observed selectivity over these metals is likely controlled by the significantly higher activation barriers to hydrogenate the C═O bond compared with those required to hydrogenate the C═C bond. Both the unsaturated alcohol and the saturated ketone, which are the primary reaction products, are strongly bound to Ru and can react further to the saturated alcohol. The lower calculated barriers for the hydrogenation steps over Pt compared with Ru account for the higher observed turnover frequencies for the hydrogenation of MVK and BA over Pt. The presence of a phenyl substituent α to the C═C bond in BA increased the barrier for C═C hydrogenation over those associated with the C═C bond in MVK; however, the increase in barriers with phenyl substitution was not adequate to reverse the selectivity trend.

Process Analytical Chemistry in a Zinc Electroplating Bath: Automatic Sequential Injection for Additives Determination

Process analytical chemistry (PAC) is applied to a zinc electroplating bath to monitor the concentration of benzylidene acetone (BDA) and benzoic acid (BA) additives. BA tends to maintain its concentration during the use of bath but BDA degrades according to a first-order law causing the bath to function improperly. The methodology includes the use of sequential injection (SI) as a flow method to automatically conduct samples of bath to a diode-array UV detector for spectra acquisition after proper dilution. Dedicated software has been developed using the LabVIEW environment for the control of a multiburette and selection and injection valves. The software is available on request. The UV signal is used to develop a partial least squares (PLS) calibration model that can resolve the mixture of additives. Mean calibration and validation errors for BDA and BA under 3.7% and 5.2% respectively were found. The results do not differ significantly from those obtained with a manual method used as a reference. Excellent results were obtained when the automated method was applied along a whole bath life and it can be used to maintain the proper plating conditions.

벤질리덴아세톤 화학구조 변이에 따른 생리활성 변화 분석 및 식물 병해충 방제 효과

Benzylideneacetone (BZA) is a compound derived from culture broth of an entomopathogenic bacterium, Xenorhabdus nematophila (Xn). Its immunosuppressive activity is caused by its inhibitory activity against eicosanoid biosynthesis. This BZA is being developed as an additive to enhance control efficacy of other commercial microbial insecticides. This study was focused on the enhancement of the immunosuppressive activity of BZA by generating its chemical derivatives toward decrease of its hydrophobicity. Two hydroxylated BZA and one sugar-conjugated BZA were chemically synthesized. All derivatives had the inhibitory activities of BZA against phospholipase () and phenoloxidase (PO) of the diamondback moth, Plutella xylostella, but BZA was the most potent. Mixtures of any BZA derivative with Bacillus thuringiensis (Bt) significantly increased pathogenicity of Bt. BZA also inhibited colony growth of four plant pathogenic fungi. However, BZA derivatives (especially the sugar-conjugated BZA) lost the antifungal activity. These results indicated that BZA and its derivatives inhibited catalytic activities of two immune-associated enzymes ( and PO) of P. xylostella and enhanced Bt pathogenicity. We suggest its use to control plant pathogenic fungi.

Benzylideneacetone suppresses both cellular and humoral immune responses of Spodoptera exigua and enhances fungal pathogenicity

An entomopathogenic fungus, Beauveria bassiana, had significant insecticidal activity against the beet armyworm, Spodoptera exigua. However, it took almost one week to cause significant mortality. This study used a mixture treatment with an immunosuppressant to enhance the fungal pathogenicity. A bacterial metabolite, benzylideneacetone (BZA), had a significant synergistic effect on the fungal pathogenicity against S. exigua, although it had little insecticidal activity by itself. The mixture treatment shortened median lethal time of B. bassiana by approximately 2 days. The synergistic activity of BZA on the pathogenicity of B. bassiana was induced by its immunosuppressive effects on both cellular and humoral antifungal responses of S. exigua. In response to B. bassiana, S. exigua larvae can form hemocytic nodules. Nodules were significantly suppressed by BZA treatment. Moreover, BZA inhibited expression of some antimicrobial peptide genes of S. exigua in response to fungal challenge. The immunosuppressive condition induced by BZA allowed B. bassiana to easily colonize and multiply in the hemocoel of treated larvae, which resulted in significant enhancement of the pathogenicity of B. bassiana.

Electrodeposition and corrosion behavior of Zn coatings formed using as brighteners arene additives of different structure

This study examined the effect of the molecular structure of the aliphatic chain in arenes (phenyl + aliphatic chain) used as brightener additives on the reduction kinetics, morphology and corrosion resistance of Zn coatings formed by reduction of Zn(II) ions in a chloride electrolytic bath. Three such brighteners were tested—benzylideneacetone (BDA), benzylacetone (BA) and butylbenzene (BB)—dissolved in polyethyleneglycol (MW200) PEG 200, in order to determine the influence of the phenyl, carbonyl and/or C = C double bond present in these compounds on the zinc reduction process. The results showed that, in the presence of PEG 200 alone, the reduction rate (j 0) of Zn(II) ions was higher than in the absence of additives. By contrast, in the presence of the brightener-PEG 200 mixtures, the values of j 0 were lower, leading to a reduction in the size of the Zn clusters. Among the brighteners tested, no significant differences were observed in the values of j 0 as a function of the molecular structure of the arene aliphatic chain. SEM analysis revealed a change in the Zn coating morphology from hexagonal crystals with a (101) preferred orientation in the absence of additives, to flakes grouped in hemispherical clusters with (002), (100) and (101) crystallographic orientations when PEG 200 or brightener-PEG 200 mixtures were present in the electrolytic bath. In addition, the cluster size decreased in accordance with the j 0 values. The comparison of the values of corrosion current density indicates that there are no significant differences between them.

Bacterial Metabolites of an Entomopathogenic Bacterium, Xenorhabdus nematophila, Inhibit a Catalytic Activity of Phenoloxidase of the Diamondback Moth, Plutella xylostella

A monoterpenoid compound, benzylideneacetone (BZA), is identified from bacterial metabolites synthesized by an entomopathogenic bacterium, Xenorhabdus nematophila. It inhibits phospholipase A2 of target insects to shut down biosynthesis of various eicosanoids, which play significant roles in insect immunity. This study discovered another novel activity of BZA that directly inhibited phenoloxidase (PO) activity required for immune-associated melanization. When it was injected into larvae of Plutella xylostella, it suppressed PO activity in the plasma by inhibiting its activation from inactive proPO. However, BZA did not influence on gene expression of PO, which was analyzed by RT-PCR using gene-specific primers designed from a partial cDNA sequence of PO of the P. xylostella identified in this study. To test a direct inhibitory activity of BZA against PO, the activated PO of P. xylostella was prepared from the hemolymph collected from the larvae challenged by bacteria. When the activated PO was incubated in vitro with BZA, it was inhibited in a dose-dependent manner. The inhibition of PO by BZA was recovered by addition of increasing amounts of substrate, L-3,4-dihydroxyphenylalanine. Three other known bacterial metabolites containing a benzene propane core structure synthesized by X. nematophila also inhibited the PO enzyme activity. However, modification of the core structure by hydroxylation of BZA lost its strong inhibitory activity against the activated PO.

Sn–Cu Alloy Electrodeposition and Its Connecting Reliability for Automotive Connectors

The electrodeposition behavior of Sn–Cu alloys in a sulfate solution containing three additives, cresol sulfonic acid, benzal acetone, and nonionic alkyl polyethylene glycol ether surfactant, was investigated potentiostatically between +0.3 and � 0:7 V vs. NHE at 298 K. The contact resistance of the alloys deposited on a Cu connector was evaluated. Cu in the alloys behaved as a more noble metal than did Sn, thus showing the typical feature of regular-type codeposition. In solutions containing additives, the difference in deposition potential between Cu and Sn decreased because Cu deposition was significantly suppressed by the additives. The alloys deposited in solutions containing additives exhibited smooth surfaces and were composed of Cu, Sn, Cu6Sn5, and Cu3Sn phases in accordance with the equilibrium phase diagram of a binary Cu–Sn system. The contact resistance of the alloys increased by heating at 433 K, thus indicating that connecting reliability did not improve by plating with the stable metallic compound Cu6Sn5. The connecting reliability of a connector after abrasion was higher in deposited alloy films than in Sn reflow plating. [doi:10.2320/matertrans.M2011022]

自動車接点材料用の Sn-Cu 合金電析とその電気的接続性

Electrodeposition behavior of Sn-Cu alloys was investigated potentiostatically at 0.3 to −0.7 V vs. NHE and 298 K in sulfate bath containing additives of cresol sulfonic acid, benzal acetone and nonionic alkyl polyethylene glycol ether surfactant, and the contact resistance of Sn-Cu alloys deposited on Cu connector was evaluated. Cu behaved as more noble metal than Sn, showing the typical feature of regular type codeposition. In solution containing additives, the difference of deposition potential between Cu and Sn became small because Cu deposition was suppressed by the additives. The Sn-Cu alloys deposited from solution containing additives showed smooth surface. The deposited Sn-Cu alloys were composed of Cu, Sn, Cu6Sn5 and Cu3Sn phases in accordance with the equilibrium phase diagram of binary Cu-Sn system. The contact resistance of deposited Sn-Cu alloys increased by heating at 433 K, showing no improvement of connecting reliability by plating the stable metallic compound of Cu6Sn5. The connecting reliability of connector after abrasion was better in deposited films of Sn-Cu alloys than in reflow Sn plating.

Benzylideneacetone, an eicosanoid biosynthesis inhibitor enhances baculovirus pathogenicity in the diamondback moth, Plutella xylostella

Benzylideneacetone (BZA) is a monoterpenoid compound produced by an entomopathogenic bacterium, Xenorhabdus nematophila. BZA inhibits phospholipase A 2 to suppress biosynthesis of eicosanoids that mediate immune responses in insects. In response to per os infection of Autographa californica multiple nucleopolyhedrosis virus (AcMNPV), the diamondback moth, Plutella xylostella, developed red spots on the midgut epithelium. The midgut exhibiting red spot formation suffered abnormal cell integrity, such as genomic DNA fragmentation and condensed spots in the nucleoplasm. The number of red spots increased with viral dose and incubation time after the viral treatment. BZA inhibited the formation of the midgut red spots in a dose-dependent manner. However, the inhibitory effect of BZA on the red spot formation was reversed by addition of arachidonic acid, suggesting that the red spot response may be mediated by eicosanoids. BZA treatment resulted in significant enhancement of AcMNPV occlusion body (OB) pathogenicity to P. xylostella.

ChemInform Abstract: Synthesis of Cycloheptenyldiphenylphosphine Oxides from the Reactions of a Cyclic Phosphonium Salt with α,β-Unsaturated Carbonyl Compounds.

The reactions of the ylide from the five-membered cyclic phosphonium salt 1 with methyl vinyl ketone, chalcone, and benzylidene acetone afforded cycloheptenyldiphenylphosphine oxides via a Michael-type reaction followed by an intramolecular Wittig reaction.

Xenorhabdus nematophilla 유래물질 벤질리덴아세톤의 고추 병해 방제 효과

벤질리덴아세톤은 모노테르펜 화합물로 곤충병원세균인 Xenorhabdus nematophilla K1의 대사물질이다. 본 연구는 벤질리덴아세톤을 이용하여 고추의 두 가지 주요 병해에 대한 방제 가능성이 조사되었다. 벤질리덴아세톤은 역병균 Phytophthora capsici와 탄저병균 Colletotrichum acutatum에 대해 강력한 억제능력을 가지고 있었다. 이러한 벤질리덴아세톤의 항균력은 태양이 비치는 자연조건에서 60일 이상 유지되었으며, 토양수 내에서도 상실되지 않았다. 벤질리덴아세톤을 혼합한 토양에 심겨진 고추 근권토양에 Phytophthora capsici 현탁액을 관주하였을 때, 역병 발생이 크게 감소되었다. 또한 Colletotrichum acutatum에 오염된 고추 열매 표면에 벤질리덴아세톤 용액을 살포하여 탄저병 발생을 억제할 수 있었다. 이러한 결과는 벤질리덴아세톤을 고추 역병과 탄저병 방제용 농약으로 개발할 수 있음을 제시하고 있다. A monoterpenoid benzylideneacetone (BZA) is a bacterial metabolite isolated from culture broth of an entomopathogenic bacterium, Xenorhabdus nematophila K1. It was tested in this study the control efficacy of the metabolite against two major fungal diseases occurring in red-pepper plants. BZA exhibited significant antifungal activities against Phytophthora capsici and Colletotrichum acutatum. Under natural light conditions, the antifungal activity of BZA was maintained for more than sixty days. The antifungal activity of BZA was not lost even in soil because the incidence of Phytophthora blight against red-pepper plants was significantly reduced when the suspensions of P. capsici were poured to the rhizosphere soils mixed with BZA. Application of the BZA suspension spray to the fruit surface infected with C. acutatum significantly suppressed the disease occurrence of anthracnose on the red-pepper plants. These results suggest that BZA can be used to develop a promising agrochemical to control phytophthora blight and anthracnose of redpepper plants.

Determination of additives in an electrolytic zinc bath by q1H-NMR spectroscopy

The use of proton nuclear magnetic resonance ((1)H-NMR) for the quantification of additives in an electrolytic Zn bath is reported. A simple and quick method is described that does not need any prior sample preparation. Contrary to other analytical methods, the three additives in the bath, benzylidene acetone (BDA), benzoic acid (BA) and poly(ethylene glycol) (PE400), can be quantified. Two calibration methods were tried: integration of NMR signals with the use of an internal standard and partial least squares (PLS) regression applied to the characteristic NMR peaks. Both methods are compared and the univariate method was preferred because of simplicity, accuracy and precision. The following limits of detection were found: 0.30 g L(-1) BA, 0.08 g L(-1) BDA and 0.7 g L(-1) PE400 with dynamic ranges of at least 1.0-6.0, 0.1-0.6 and 3.0-18.0 g L(-1) respectively. Those concentration ranges are suitable to follow the concentration of additives in the bath in real time. (1)H-NMR spectra provide evidence for the BDA degradation pattern.

Synthesis and anti-inflammatory activity of novel (substituted)benzylidene acetone oxime ether derivatives: Molecular modeling study

Herein, we report the design, synthesis, and pharmacological properties of a series of substituted benzylidene acetone oxime ether derivatives from the corresponding oxime derivatives. All the newly synthesized compounds were investigated in vivo for their anti-inflammatory activities using carrageenin-induced rat paw oedema model. Among the compounds examined, compounds 5b and 7a showed the highest activity, nearly equivalent to that of the standard drug diclofenac sodium. Hence, they were screened for their analgesic activities using acetic acid-induced writhing model in mice and also, their ulcerogenic effects were studied. Compound 7a was found to possess significant anti-inflammatory and analgesic activities with negligible ulcerogenic effect. Docking study of the synthesized compound 7a into the active site of COX-1 and COX-2 revealed a similar binding mode to SC-558, a selective COX-2 inhibitor.

Two chemical derivatives of bacterial metabolites suppress cellular immune responses and enhance pathogenicity of Bacillus thuringiensis against the diamondback moth, Plutella xylostella

Eicosanoids mediate insect immune responses, especially against bacterial infection. Phospholipase A 2 (PLA 2) catalyzes the committed step of the eicosanoid biosynthesis pathway. Three PLA 2 inhibitors have been identified from metabolites of an entomopathogenic bacterium, Xenorhabdus nematophila: benzylideneacetone (BZA), Pro-Tyr (PY), and acetylated Phe-Gly-Val (Ac-FGV). Interestingly, they share benzenepropane as a core chemical structure. We analyzed the functional significance of the core structure using structural derivatives. Removing a phenyl ring from PY resulted in significant loss of the PLA 2 inhibitory activity, as seen in a Pro-Ala derivative. Though the p-hydroxyl group was not critical in PY as seen in Pro-Phe derivative, its addition to BZA resulted in significant loss of inhibitory activity. Some alterations of structures other than the core structure increased PLA 2-inhibitory activity in some derivatives, including Ala-Tyr (AY) and Phe-Gly-Val (FGV) derivatives. Using these selected derivatives, we further analyzed synergistic effects on pathogenicity of Bacillus thuringiensis (Bt) against the second instar larvae of Plutella xylostella. These two derivatives significantly enhanced the Bt pathogenicity. This study introduces two novel compounds that inhibit PLA 2 and suggests their application in combination with Bt to control P. xylostella.

Ion-tagged π-acidic alkene ligands promote Pd-catalysed allyl–aryl couplings in an ionic liquid

Ionic pi-acidic alkene ligands based on chalcone and benzylidene acetone frameworks have been "doped" into ionic liquids to provide functional reaction media for Pd-catalysed cross-couplings of a cyclohexenyl carbonate with aryl siloxanes that allow simple product isolation, free from Pd (<50 ppm) and ligand contamination.