Presence Of Ether Research Articles

Low concentration 1-MCP limit ripening process of mango cv. ‘gedong gincu’ during low temperature storage

Mango fruit still ripens and senesces after harvest. The presence of ethylene will shorten the shelf life of mangoes during long transportation processes. The purpose of this research is to find out how long the ‘gedong gincu’ mango (Mangifera indica L.) can be kept at 15°C after being treated with 1-methylcyclopropene (1-MCP). This study conducted experiments in the lab using a completely randomized approach with a single factor that included treatment with and without 500 ppb 1-MCP. Both was kept at 15°C for both sessions. Weight, color, hardness, total dissolved solids, total titrated acid, and chilling injury score were measured in this study. Analysis of data will be conducted using a t-test at α = 5% using Microsoft Analysis Toolpak. The study found that adding 1-MCP to mango cv ‘gedong gincu’ had a significant effect (p<0.05) on its color change, hardness, total titrated acidity, and chilling injury score during storage at low temperatures. This suggests that 1-MCP may be able to delay the ripening process by ethylene and extend the shelf life of ‘gedong gincu’ mangoes when stored at 15°C, thereby contributing largely to food loss prevention.

Automated de Novo Design of Olefin Metathesis Catalysts: Computational and Experimental Analysis of a Simple Thermodynamic Design Criterion.

Methods for computational de novo design of inorganic molecules have paved the way for automated design of homogeneous catalysts. Such studies have so far relied on correlation-based prediction models as fitness functions (figures of merit), but the soundness of these approaches has yet to be tested by experimental verification of de novo-designed catalysts. Here, a previously developed criterion for the optimization of dative ligands L in ruthenium-based olefin metathesis catalysts RuCl2(L)(L')(═CHAr), where Ar is an aryl group and L' is a phosphine ligand dissociating to activate the catalyst, was used in de novo design experiments. These experiments predicted catalysts bearing an N-heterocyclic carbene (L = 9) substituted by two N-bound mesityls and two tert-butyl groups at the imidazolidin-2-ylidene backbone to be promising. Whereas the phosphine-stabilized precursor assumed by the prediction model could not be made, a pyridine-stabilized ruthenium alkylidene complex (17) bearing carbene 9 was less active than a known leading pyridine-stabilized Grubbs-type catalyst (18, L = H2IMes). A density functional theory-based analysis showed that the unsubstituted metallacyclobutane (MCB) intermediate generated in the presence of ethylene is the likely resting state of both 17 and 18. Whereas the design criterion via its correlation between the stability of the MCB and the rate-determining barrier indeed seeks to stabilize the MCB, it relies on RuCl2(L)(L')(═CH2) adducts as resting states. The change in resting state explains the discrepancy between the prediction and the actual performance of catalyst 17. To avoid such discrepancies and better address the multifaceted challenges of predicting catalytic performance, future de novo catalyst design studies should explore and test design criteria incorporating information from more than a single relative energy or intermediate.

Role of Ethylene in the Regulation of Plant Developmental Processes

Ethylene, a gaseous phytohormone, is emerging as a central player in the intricate web of plant developmental processes from germination to senescence under optimal and stressed conditions. The presence of ethylene has been noted in different plant parts, including the stems, leaves, flowers, roots, seeds, and fruits. This review aims to provide a comprehensive overview of the regulatory impact of ethylene on pivotal plant developmental processes, such as cell division and elongation, senescence, abscission, fruit and flower development, root hair formation, chloroplast maturation, and photosynthesis. The review also encompasses ethylene biosynthesis and signaling: a snapshot of the regulatory mechanisms governing ethylene production. Understanding of the impact of ethylene’s regulatory functions on plant developmental processes has significant implications for agriculture, biotechnology, and our fundamental comprehension of plant biology. This review underscores the potential of ethylene to revolutionize plant development and crop management.

Aldol condensation of mixed oxygenates on TiO2

Kinetic studies of aldol condensation of mixtures on TiO2 reveal strong suppression of acetone self-condensation in the presence of acetaldehyde.

Influence of Ethanol Decomposition on Dispersion of PEFC Catalyst Ink

To achieve high power density operation of polymer electrolyte fuel cells (PEFCs), it is required to realize high-performance catalyst layer with low oxygen transport resistance, high proton and electron conductivities, and high electrochemical surface area (ECSA) with low Platinum loading. Because dispersion structure of catalyst ink strongly affects porous structure of the catalyst layer, it is crucial for realization of high-performance catalyst layer to understand the dispersion mechanism of the catalyst ink. Our group has reported that decomposition of ethanol, as a solvent, by platinum catalyst significantly affects aggregation of the catalyst ink. [1, 2] But, the mechanism of the catalyst ink aggregation was not fully understood. In this study, effect of ethanol decomposition on the aggregation of the catalyst ink was investigated.The catalyst ink was fabricated by mixing platinum-supported carbon (TEC10V30E, Tanaka Kikinzoku), ionomer (DE1021, Sigma-Aldrich), and water/ethanol solvent (water/ethanol: 60/40 wt%). Decomposition product of ethanol within the catalyst ink solvent was analyzed by GC/MS (GCMS-QP2020NX, SHIMADZU), and presence of acetaldehyde (C2H4O) and acetic acid (CH3COOH) was detected. In order to investigate the influence of these products on aggregation of the catalyst ink, acetaldehyde or acetic acid was added to the catalyst ink. The particle size distribution was evaluated by using laser diffraction type particle size distribution meter (LA-960V2, HORIBA) without dilution, and it was confirmed that the acetaldehyde-added catalyst ink showed larger particle size and the acetaldehyde caused the aggregation of the catalyst ink (Figure 1). In addition, dispersion of the catalyst ink was observed by using an optical microscopy, and aggregation of the catalyst ink by adding the acetaldehyde was clearly observed (Figure 2). To understand the aggregation mechanism by adding acetaldehyde, ionomer adsorption fraction on the platinum-supported carbon was measured by using centrifugation method, and the decrease in ionomer adsorption fraction by adding acetaldehyde was confirmed. From these results, it was confirmed that acetaldehyde generated by the decomposition of ethanol in the catalyst ink leads to a decrease in the ionomer adsorption fraction. It is reported that the ionomer promotes the dispersion of platinum-supported carbon due to electrostatic repulsion forces, and it is suggested that the decrease in ionomer adsorption fraction results in the aggregation of the catalyst ink. Therefore, to realize high-performance catalyst layer, influence of acetaldehyde should be minimized and further research is requested to understand it. Acknowledgement This presentation is based on results obtained from a project commissioned by the New Energy and Industrial Technology Development Organization (NEDO).

Ethane-CO2 Mixture Adsorption in Silicalite: Influence of Tortuosity and Connectivity of Pores on Selectivity

Selective adsorption using nanoporous materials is an efficient strategy for separating gas mixtures. In a nanoporous material, pores can exist in different shapes and can have different degrees of inter-connectivity. In recent studies, both pore connectivity and tortuosity have been found to affect the adsorption and dynamical properties of ethane and CO2 in silicalite differently. Here, using Monte Carlo simulations, we investigate if these two attributes can affect the selective adsorption of one component from a mixture of ethane and CO2 in silicalite. For this, the adsorption of an equimolar mixture of ethane and CO2 is simulated in 12 models of silicalite—SnZm (n, m = 0, 1, 2, 3 or 4; with n and m denoting, respectively, the fraction (out of 4) of straight and zigzag channels of silicalite that are available for adsorption)—differing in degrees of pore connectivity and tortuosity. The adsorption selectivity in this system is found to exhibit a reversal with the adsorption dominated by ethane at low pressures (below ~1 atm) and by CO2 at higher pressures (above ~10 atm). Pore connectivity is found to suppress the selective adsorption of CO2 at higher pressures and also shifts the selectivity reversal to higher pressures. The selectivity reversal results from a competition between the polarizability-affected adsorption at lower pressures and efficient packing at higher pressures. The efficient packing of CO2 is a compounded effect resulting from the larger effective pore volume available for CO2 due to its stronger interaction with the pore surface and smaller molecular volume. CO2 molecules show a preference to adsorb in non-tortuous pores, and this preference is found to be stronger in the presence of ethane. The effects of pore connectivity and tortuosity elucidated here should be applicable to a wide range of natural and engineered nanoporous materials, and this knowledge could be used to identify materials with better capability for separating and storing CO2 based on their pore attributes.

Co-aromatization of light alkanes over Mo/ZSM-5: How the presences of CH4 and C2H6 & C3H8 influence the aromatization of each other

The chemical inertness of methane is a significant bottleneck for its direct conversion into value-added light aromatics. However, co-feeding higher hydrocarbons with methane produces intermediates that facilitate the participation of methane in aromatization. This synergistic effect has typically been observed under conditions that do not allow the conversion of methane without any co-reactants (over non-Mo-based catalysts at temperatures below 650 ℃). Therefore, the interaction between methane and higher hydrocarbons remains unexplored under conditions that allow methane activation. In this study, we explored the behavior of co-reactants in the direct aromatization of simulated shale gas (a mixture of methane, ethane, and propane) over Mo/ZSM-5. Our aim was to comprehend the complex co-aromatization system under conditions optimized for rigorous activation of methane, which leads to a considerable production of aromatics. The majority of reaction indices in the shale gas aromatization system were governed by the presence of ethane and propane, which were represented by a rapid catalytic lifetime cycle. Mathematical calculations, based on experimentally derived C and H balances, revealed an unexpected anti-synergy within the components of shale gas where the conversion of methane to aromatics was partially suppressed by the presence of ethane and propane. These findings expand the understanding of the complex yet desirable shale gas aromatization system, and also highlight the need for the development of new catalysts capable of further enhancing the activity of methane among the reactants.

Combining methane clumped and bulk isotopes, temporal variations in molecular and isotopic composition, and hydrochemical and geological proxies to understand methane's origin in the Ronda peridotite massifs (Spain)

In serpentinised peridotite and ultramafic rock systems, methane (CH4) origin is frequently considered abiotic, but variable microbial and thermogenic components can also exist. Typically, the origin of CH4 is studied using bulk, 13C/12C and 2H/H isotopic composition, molecular gas composition, occasionally radiocarbon (14C), microbiology and geological context. Recent advances in CH4-clumped isotope methods have yielded novel insights into the formation of CH4: nonetheless, their interpretation in natural gas samples is often uncertain and requires additional research. Here, we study the origin of the gas released in hyperalkaline (pH > 10) springs in the Ronda Peridotite Massifs (southern Spain), combining bulk and clumped CH4 isotopes with molecular gas composition, hydrochemical (Total Organic Carbon and Platinum Group Elements in water), geothermal and geo-structural data. Five springs analysed in 2014 have been re-examined for changes in gas chemistry over time, and three newly discovered gas-bearing springs are analysed for the first time. Regardless of whether springs have microbial or abiotic isotopic fingerprints, we find that bulk CH4 isotopes are fairly stable over a seven-year period. This suggests that the CH4 source(s) or postgenetic processes (such as oxidation and diffusion) have not undergone significant temporal changes. Major variations in H2 and CH4 concentrations in certain springs may be the result of changes in gas pressure and migration intensity. Paired CH4 clumped isotopes (Δ12CH2D2 - Δ13CH3D) were analysed in two bubbling springs, where the presence of CH4 can be interpreted as non-microbial based on 13C enrichment, absence of 14C, and the presence of ethane and propane. However, these isotopes are in disequilibrium, which prevents the quantification of the gas formation temperature. Within the Δ12CH2D2 - Δ13CH3D diagram, the data lie within both the microbialgenic zone, suggested by previous authors, and the abiotic zone that results combining data from laboratory gas synthesis and other natural gas samples. Therefore, attributing a microbial origin to CH4 based only on clumped isotopes is less definite than previously assumed. The amount of Total Organic Carbon appears to be correlated with the origin of CH4, as it is higher in 13C-depleted CH4 samples and lower in 13C-enriched samples. Palladium (Pd) and Rhodium (Rh) dissolved in water (the more soluble Platinum Group Elements) can be a proxy for the chromitite ore deposits contained in plagioclase tectonite layers throughout the investigated area, which may act as catalysts for abiotic CO2 hydrogenation. Clumped isotope disequilibrium and the reported absence of diffuse CH4-bearing fluid inclusions in the peridotites appear to rule out high temperature gas genesis in post-magmatic inclusions. These observations, along with the moderate temperatures at the base of the peridotite massifs and the consistent occurrence of gas along tectonic contacts between serpentinised (H2-bearing) peridotite and carbon-bearing rocks, are compatible with the theory of low-temperature CO2 hydrogenation.

From cellulose to tar: Analysis of tar formation pathway with distinguishing the primary and secondary reactions

Tar problem seriously hinders the development of biomass gasification. The tar formation of biomass is greatly influenced by cellulose. In this work, PY-GC/MS was employed for providing a precise insight into the formation of primary and secondary products, and a tar contribution index was introduced to evaluate the potential of tar formation from different origins. Combined with statistical analysis and corroboration by DFT analysis, key intermediates for tar formation are recognized, and corresponding influence is confirmed. A new framework from cellulose to tar was built. The secondary reaction acts a more important role for tar formation. The aromatic precursors and high-activity small-molecular gases are two key compounds responding to tar formation, and the existence of high-activity small-molecular gases could significantly reduce the energy barrier during tar formation. For furans, the energy barrier can be reduced from 100.2 kcal/mol to 74.2 kcal/mol in the presence of ethylene.

Three Innovative Green and High-Throughput Microwell Spectrophotometric Methods for the Quantitation of Ceritinib, a Potent Drug for the Treatment of ALK-Positive Non-Small Cell Lung Cancer: An Application to the Analysis of Capsules and Drug Uniformity Testing.

Ceritinib (CER) is a potent drug that has been recently approved by the Food and Drug Administration for the treatment of patients with non-small cell lung cancer harboring the anaplastic lymphoma kinase mutation gene. The existing methods for the quality control of CER are very limited and suffer from limited analytical throughput and do not meet the requirements of the green analytical principles. This study presented the first-ever development and validation of three innovative green and high-throughput microwell spectrophotometric methods (MW-SPMs) for the quality control of CER in its dosage form (Zykadia® capsules). These MW-SPMs were based on the formation of colored N-vinylamino-substituted haloquinone derivatives of CER upon its reactions with each of chloranil, bromanil, and 2,3-dichloro-1,4-naphthoquinone in the presence of acetaldehyde. The optimized procedures of the MW-SPMs were established, and their analytical performances were validated according to the ICH. The linear range of the MW-SPMs was 5-150 µg/mL, with limits of quantitation of 5.3-7.6 µg/mL. The accuracy and precision of the MW-SPMs were proved, as the average recovery values were 99.9-101.0%, and the relative standard deviations did not exceed 1.8%. The three methods were applied to the determination of CER content in Zykadia® capsules and drug content uniformity testing. The greenness of the MW-SPMs was proved using three different metric tools. In addition, these methods encompassed the advantage of high-throughput analysis. In conclusion, the three methods are valuable tools for convenient and reliable application in the pharmaceutical quality control units for CER-containing capsules.

The CALCINEURIN B-LIKE4/CBL-INTERACTING PROTEIN3 module degrades repressor JAZ5 during rose petal senescence.

Flower senescence is genetically regulated and developmentally controlled. The phytohormone ethylene induces flower senescence in rose (Rosa hybrida), but the underlying signaling network is not well understood. Given that calcium regulates senescence in animals and plants, we explored the role of calcium in petal senescence. Here, we report that the expression of calcineurin B-like protein 4 (RhCBL4), which encodes a calcium receptor, is induced by senescence and ethylene signaling in rose petals. RhCBL4 interacts with CBL-interacting protein kinase 3 (RhCIPK3), and both positively regulate petal senescence. Furthermore, we determined that RhCIPK3 interacts with the jasmonic acid response repressor jasmonate ZIM-domain 5 (RhJAZ5). RhCIPK3 phosphorylates RhJAZ5 and promotes its degradation in the presence of ethylene. Our results reveal that the RhCBL4-RhCIPK3-RhJAZ5 module mediates ethylene-regulated petal senescence. These findings provide insights into flower senescence, which may facilitate innovations in postharvest technology for extending rose flower longevity.

Titania nanoparticles for photocatalytic degradation of ethanol under simulated solar light.

TiO2 nanoparticles were synthesized by laser pyrolysis from TiCl4 vapor in air in the presence of ethylene as sensitizer at different working pressures (250-850 mbar) with and without further calcination at 450 °C. The obtained powders were analyzed by energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, X-ray diffractometry, and transmission electron microscopy. Also, specific surface area and photoluminescence with optical absorbance were evaluated. By varying the synthesis parameters (especially the working pressure), different TiO2 nanopowders were obtained, whose photodegradation properties were tested compared to a commercial Degussa P25 sample. Two series of samples were obtained. Series "a" includes thermally treated TiO2 nanoparticles (to remove impurities) that have different proportions of the anatase phase (41.12-90.74%) mixed with rutile and small crystallite sizes of 11-22 nm. Series "b" series represents nanoparticles with high purity, which did not require thermal treatment after synthesis (ca. 1 atom % of impurities). These nanoparticles show an increased anatase phase content (77.33-87.42%) and crystallite sizes of 23-45 nm. The TEM images showed that in both series small crystallites form spheroidal nanoparticles with dimensions of 40-80 nm, whose number increases with increasing the working pressure. The photocatalytic properties have been investigated regarding the photodegradation of ethanol vapors in Ar with 0.3% O2 using P25 powder as reference under simulated solar light. During the irradiation H2 gas production has been detected for the samples from series "b", whereas the CO2 evolution was observed for all samples from series "a".

Effect of applications of 1-MCP and ethylene on the ripening and degreening process of banana fruits cv. Barranquillo

The banana cv. Barranquillo (Musa acuminata, AAA, ‘Gros Michel’) is a highly desired fruit because of its productive potential and organoleptic quality but various aspects of the ripening process are unknown. The objective of this research was to evaluate the effect of applications of 1-MCP and ethylene on the ripening and degreening process. Two experiments were carried out at room temperature with fruits harvested at commercial maturity. The first four treatments evaluated maturation: control, ethylene, 1-MCP, and 1-MCP + ethylene. In the second experiment, different concentrations of ethylene based on ethephon (0, 100, 500 and 1000 μL L-1) were evaluated. The fruits treated with 1-MCP decreased the ripening process, and 1-MCP was a good alternative for conserving the fruits; the ethylene had opposite results. The color index of the skin, weight loss, firmness, total soluble solids, and maturity ratio had changes associated with the presence of ethylene. In the second experiment, the ethylene applications between 100 and 500 μL L-1 sufficiently stimulated degreening but accelerated the ripening process.

Corrosion inhibition study of 6061 aluminium alloy in the presence of ethyl 5-methyl-1-(4-nitrophenyl)-1H-1,2,3-triazole-4-carboxylate (NTE) in hydrochloric acid

The inhibitory effect of an ethyl 5-methyl-1-(4-nitrophenyl)-1H-1,2,3-triazole-4-carboxylate (NTE) was investigated on the corrosion of Al (AA6061) alloy at different temperatures (303–333 K) by Electrochemical impedance spectroscopy (EIS), Potentiodynamic polarization (PDP), and weight loss techniques. It was found that NTE molecules protect the aluminium against corrosion and its ability increases with increasing concentrations, and temperature resulting in better inhibitory performance. At all concentrations and temperature ranges, NTE exhibited mixed inhibitor action and complied with the Langmuir isotherm. At 100 ppm and 333 K, NTE demonstrated the highest inhibition efficiency (94%). The EIS results and the PDP results had a good level of concordance. A suitable mechanism for the corrosion prevention of AA6061 alloy was proposed. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to confirm the adsorption of an inhibitor onto the aluminium alloy surface. The electrochemical results were validated by morphological examination, which demonstrated that NTE prevents uniform corrosion of aluminium alloy in acid chloride solutions. The activation energy and thermodynamic parameters were computed, and the results were discussed.

An overview of ethylene insensitive tomato mutants: Advantages and disadvantages for postharvest fruit shelf-life and future perspective.

The presence of ethylene during postharvest handling of tomatoes can be the main problem in maintaining fruit shelf-life by accelerating the ripening process and causing several quality changes in fruit. Several researchers have studied the methods for improving the postharvest life of tomato fruit by controlling ethylene response, such as by mutation. New ethylene receptor mutants have been identified, namely Sletr1-1, Sletr1-2, Nr (Never ripe), Sletr4-1, and Sletr5-1. This review identifies the favorable and undesirable effects of several ethylene receptor mutants. Also, the impact of those mutations on the metabolite alteration of tomatoes and the future perspectives of those ethylene receptor mutants. The review data is taken from the primary data of our experiment related to ethylene receptor mutants and the secondary data from numerous publications in Google Scholar and other sources pertaining to ethylene physiology. This review concluded that mutation in the SlETR1 gene was more effective than mutation in NR, SLETR4, and SLETR5 genes in generating a new ethylene mutant. Sletr1-2 mutant is a potential ethylene receptor mutant for developing new tomato cultivars with prolonged fruit-shelf life without any undesirable effect. Therefore, that has many challenges to using the Sletr1-2 mutant for future purposes in breeding programs.

Accurate selected ion flow tube mass spectrometry quantification of ethylene oxide contamination in the presence of acetaldehyde.

In September 2020, traces of ethylene oxide (a toxic substance used as a pesticide in developing countries but banned for use on food items within the European Union) were found in foodstuffs containing ingredients derived from imported sesame seed products. Vast numbers of foodstuffs were recalled across Europe due to this contamination, leading to expensive market losses and extensive trace exposure of ethylene oxide to consumers. Therefore, a rapid analysis method is needed to ensure food safety by high-throughput screening for ethylene oxide contamination. Selected ion flow tube mass spectrometry (SIFT-MS) is a suitable method for rapid quantification of trace amounts of vapours in the headspace of food samples. It turns out, however, that the presence of acetaldehyde complicates SIFT-MS analyses of its isomer ethylene oxide. It was proposed that a combination of the H3O+ and NO+ reagent ions can be used to analyse ethylene oxide in the presence of acetaldehyde. This method is, however, not robust because of the product ion overlaps and potential interferences from other matrix species. Thus, we studied the kinetics of the reactions of the H3O+, NO+, OH- and O-˙ ions with these two compounds and obtained their rate coefficients and product ion branching ratios. Interpretation of these experimental data revealed that the OH- anions are the most suitable SIFT-MS reagents because the product ions of their reactions with acetaldehyde (CH2CHO- at m/z 43) and ethylene oxide (C2H3O2- at m/z 59) do not overlap.

Catabolic reprogramming of Brassica rapa leaf mesophyll protoplasts during the isolation procedure

The use of leaf mesophyll protoplasts for transformation and genome editing in plants is expected due to the distinctive features of protoplasts, such as cell-wall-free single cells. However, the application of leaf mesophyll protoplasts for molecular breeding is limited because of the recalcitrance of protoplasts to regenerate. We speculated that the primary reason for this recalcitrance is senescence during protoplast isolation before initialization. In this study, we performed profiling, clustering, co-expression analysis, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of primary metabolites and transcriptomes of Brassica rapa leaves and leaf mesophyll protoplasts to reveal the reason for senescence. Primary metabolite profiling indicated that the metabolism of B. rapa protoplasts was converted to catabolism. The number of downregulated differentially expressed genes (DEGs) increased during protoplast isolation. An analysis of GO overexpression revealed the activation of genes involved in catabolic and immune system processes and the inactivation of chloroplasts and photosynthetic genes. KEGG pathway analysis showed that the activation of autophagy and proteasomes accounted for senescence-associated proteolysis during protoplast isolation. It also revealed activation of the genes involved in endoplasmic reticulum stress responses and disease resistance responses during the first 3 h of isolation. These results suggest that elicitor receptor-mediated signal transduction stimulates the pathogen-associated molecular patterns (PAMPs), which triggers immunity. There were more downregulated than upregulated transcription factors during protoplast isolation. AT5G39610 (ANAC092, ATNAC2) gene expression was significantly activated throughout the entire period of protoplast isolation. ANAC092 was co-expressed with upregulated AT5G26340 (STP13), which encodes a protein with high affinity, hexose-specific/H + symporter. AT1G50030 encodes target of rapamycin (TOR) proteins, and the expression of TOR decreased during protoplast isolation. The presence of ethylene and the inhibition of photosynthesis-related genes by glucose and sucrose promote senescence-associated gene expression of protoplasts. Since a decrease in glucose downregulates glucose TOR signaling, the inactivated TOR signaling will promote catabolic reprogramming, senescence, and autophagy in protoplasts during protoplast isolation. We concluded that the initialization of protoplasts requires the blocking of these complicated crosstalk signaling pathways to prevent the catabolic reprogramming of protoplasts, which will lead the way to new plant breeding techniques.

Aggregation Induced Emission Supramolecular Functionalized Benzimidazole Hydrogel for Metal‐Ion Responsive and Fluorescent Anti‐Counterfeiting

AbstractStimuli‐responsive supramolecular hydrogels have established increasing attention for many applications, owing to the dynamic covalent bonds and dynamic combination chemistry involved in the construction of supramolecular hydrogels. We designate the fabrication of a new supramolecular hydrogel G2 based‐on benzimidazole in the presence of ethylene glycol/water with aggregation‐induced emission (AIE) property. The hydrogel demonstrates interesting switchable ON‐OFF fluorescence along with the Gel‐Sol transition. With the addition of Fe3+, the AIE of hydrogel G2 was quenched meanwhile the gel state was destroyed. G2 shows tunable stimuli‐responsive for Fe3+ and interesting optical sensing properties. This outstanding behavior endows the hydrogel G2 with the capability of being used as anti‐counterfeiting.

Tungstacyclopentane Ring Contraction Yields Olefin Metathesis Catalysts.

Exposure of a solution of the square pyramidal tungstacyclopentane complex W(NAr)(OSiPh3)2(C4H8) (Ar = 2,6-i-Pr2C6H3) to ethylene at 22 °C in ambient (fluorescent) light slowly leads to the formation of propylene and the square pyramidal tungstacyclobutane complex W(NAr)(OSiPh3)2(C3H6). No reaction takes place in the dark, but the reaction is >90% complete in ∼15 min under blue LED light (∼450 nm λmax). The intermediates are proposed to be (first) an α methyl tungstacyclobutane complex (W(NAr)(OSiPh3)2(αMeC3H5)), and then from it, a β methyl version. The TBP versions of each can lose propylene and form a methylene complex, and in the presence of ethylene, the unsubstituted tungstacyclobutane complex W(NAr)(OSiPh3)2(C3H6). The W-Cα bond in an unobservable TBP W(NAr)(OSiPh3)2(C4H8) isomer in which the C4H8 ring is equatorial is proposed to be cleaved homolytically by light. A hydrogen atom moves or is moved from C3 to the terminal C4 carbon in the butyl chain as the bond between W and C3 forms to give the TBP α methyl tungstacyclobutane complex. Essentially, the same behavior is observed for W(NCPh3)(OSiPh3)2(C4H8) as for W(NAr)(OSiPh3)2(C4H8), except that the rate of consumption of W(NCPh3)(OSiPh3)2(C4H8) is about half that of W(NAr)(OSiPh3)2(C4H8). In this case, an α methyl-substituted tungstacyclobutane intermediate is observed, and the overall rate of formation of W(NCPh3)(OSiPh3)2(C3H6) and propylene from W(NCPh3)(OSiPh3)2(C4H8) is ∼20 times slower than in the NAr system. These results constitute the first experimentally documented examples of forming a metallacyclobutane ring from a metallacyclopentane ring (ring contraction) and establish how metathesis-active methylene and metallacyclobutane complexes can be formed and reformed in the presence of ethylene. They also raise the possibility that ambient light could play a role in some metathesis reactions that involve ethylene and tungsten-based imido alkylidene olefin metathesis catalysts, if not others.

Anti-inflammatory and analgesic activities of imidazolyl triazolo hydroxamic acid derivatives

Hydroxamic acids are directly related with cancer and its progression. Long term exposure with inflammatory responses, dysplasia develops which leads to cancer. Metastasis of cancer and expression of transient potential receptor ankyrin-1 are known to cause severe pain. Here, we explored the possibility of developing newer hydroxamic acid derivatives as anti-inflammatory and analgesic agent. Animals were administered with 100 mg/kg dose of the synthesized imidazolyl triazolo hydroxamic acid derivatives (FP1-FP12) and 50 mg/kg dose of standard diclofenac sodium. Carrageenan induced rat paw edema and Eddy’s hot plate methods were considered for anti-inflammatory and analgesic activities. Among all the synthesized molecules, FP10 and FP4 were the most effective anti-inflammatory and analgesic agent, respectively. The activity profile of remaining molecules as anti-inflammatory agents was as follows: FP4>FP9> FP8> FP2 and as analgesic activity profile was FP10>FP3>FP8 >FP11 >FP2 > FP12. Presence of ethyl- benzyl and furan groups in linker portion of the structure minimized both the anti-inflammatory and analgesic activities. Results have shown that compounds with electron releasing groups considerably enhance both anti-inflammatory and analgesic activities.