A new synthesis of C5-substituted 1-alkyl-1H-indole-3-carboxylic esters is reported. A series of methyl 2-arylacrylate aza-Michael acceptors were prepared with aromatic substitution to activate them ...towards Ssub.NAr reaction. Subsequent reaction with a series of primary amines generated the title compounds. Initially, the sequence was expected to produce indoline products, but oxidative heteroaromatization intervened to generate the indoles. The reaction proceeded under anhydrous conditions in DMF at 23-90 °C using equimolar quantities of the acrylate and the amine with 2 equiv. of Ksub.2COsub.3 to give 61-92% of the indole products. The reaction involves an aza-Michael addition, followed by Ssub.NAr ring closure and heteroaromatization. Since the reactions were run under nitrogen, the final oxidation to the indole likely results from reaction with dissolved oxygen in the DMF. Substrates incorporating a 2-arylacrylonitrile proved too reactive to prepare using our protocol. The synthesis of the reaction substrates, their relative reactivities, and mechanistic details of the conversion are discussed.
The base-mediated reaction of representatives of alpha-nitrocinnamic esters with malononitrile (cyanoacetates) leads to transalkenylation products-benzylidenemalononitriles (benzylidenecyanoacetates).
Kaempferia galanga is an endangered plant whose recognition as a flavoring agent and perfumery ingredient has increased its demand greatly. Therefore, the present investigation aimed at the ...identification of high-rhizome-yielding varieties of K. galanga. A total of forty-nine germplasms were collected from different parts of India and planted at CSIR-NEIST, Jorhat experimental farm, during 2013. The two-year evaluation of essential morphological and chemical data was recorded for the selection of superior rhizomes with a high rhizome yield during 2014 and 2015. Subsequently, multi-location field trials were conducted with the selected elite germplasm along with controls using a randomized complete block design, and relevant morphological traits as well as essential oil quality data were recorded for all the lines for three consecutive years during 2016, 2017 and 2018. The essential oil quality was analyzed by using GC/MS. The data obtained were statistically analyzed for stability based on rhizome yield, essential oil yield and days to maturity. A high-rhizome-yielding variety of K. galanga was identified and named Bharamputra-1.Itwas found to be stable in multi-locational trials conducted in Northeast India. The variety showed a mean rhizome yield of 10.01 tones/ha. Stability parameters, namely, βi = 1.13 and σsup.2di = −0.07 were recorded and found to be superior to those of the other examined varieties. The chemical profiling of the rhizome essential oil of the selected germplasm was also performed using GC/MS, which revealed ethyl p-methoxycinnamate (37.25%), trans-ethyl cinnamate (28.35%), endo-borneol (8.91%), eucalyptol (6.83%), (-)-camphor (3.98%) and 3-carene (3.77%) as the main components. The cultivation of this identified variety could help in the successful commercial cultivation of the crop.
Mitsunobu reactions were employed to link t-butyl esters of I-4 integrin inhibitors at each of the termini of a three-arm, 40 kDa, branched PEG. Cleavage of the t-butyl esters using HCO2H provided ...easily isolated PEG derivatives, which are potent I-4 integrin inhibitors, and which achieve sustained levels and bioactivity in vivo, following subcutaneous administration to rats.
Isocyanate homo telechelic poly(methyl methacrylate-co-acryloxy succinimide) and poly(methyl methacrylate-co-acrylamidohexanoic succinimide) were prepared and used as soft segments for polyurethanes. ...Polymer structures are characterized by SEC, Raman, and super(1)H NMR spectroscopy. The synthetic route for the preparation of alpha, omega -isocyanate-telechelic poly(methyl methacrylate- co -acryloxysuccinimide) and alpha, omega - isocyanate-telechelic poly(methyl methacrylate- co -acrylamidohexanoic succinimide) soft segments is presented. The strategy includes reversible addition fragmentation chain transfer (RAFT) copolymerization and two post polymerization modification steps. The RAFT polymerizations result in copolymers with an activated ester proportion within the polymer chains of 8% N -acryloxysuccinimide and 5% 6-acrylamidohexanoic succinimide. The reactivity ratios of the monomer pairs were determined. In a first post polymerization reaction carboxylic acid homo telechelic polymers were prepared by reacting the omega -dithiobenzoate end-group with an excess of azobis(cyanovaleric acid). In a second modification step the alpha- and omega -carboxylic acid end-groups were reacted with hexamethylene diisocyanate and 100% isocyanate telechelic copolymers were obtained. Finally segmented polyurethanes were prepared by coupling hexamethylene diisocyanate (HDI) end capped soft segments with hard segments composed of 1,4-butanediol and HDI. copyright 2013 Society of Chemical Industry
The Front Cover illustrates an efficient synthetic strategy for nucleophilic aromatic substitutions of nicotinic esters in Cyrene. This solvent, obtained from renewable cellulose waste and being ...non‐toxic, non‐mutagenic and biodegradable, integrates into Green Chemistry practices by aligning with sustainable principles and minimizing environmental impact. More information can be found in the Research Article by A. Citarella, V. Fasano et al.
The function of the αsub.1B-adrenergic receptor phosphorylation sites previously detected by mass spectrometry was evaluated by employing mutants, substituting them with non-phosphorylatable amino ...acids. Substitution of the intracellular loop 3 (IL3) sites did not alter baseline or stimulated receptor phosphorylation, whereas substitution of phosphorylation sites in the carboxyl terminus (Ctail) or both domains (IL3/Ctail) markedly decreased receptor phosphorylation. Cells expressing the IL3 or Ctail receptor mutants exhibited a noradrenaline-induced calcium-maximal response similar to those expressing the wild-type receptor, and a shift to the left in the concentration–response curve to noradrenaline was also noticed. Cells expressing the IL3/Ctail mutant exhibited higher apparent potency and increased maximal response to noradrenaline than those expressing the wild-type receptor. Phorbol ester-induced desensitization of the calcium response to noradrenaline was reduced in cells expressing the IL3 mutant and abolished in cells in which the Ctail or the IL3/Ctail were modified. In contrast, desensitization in response to preincubation with noradrenaline was unaffected in cells expressing the distinct receptor mutants. Noradrenaline-induced ERK phosphorylation was surprisingly increased in cells expressing IL3-modified receptors but not in those expressing receptors with the Ctail or IL3/Ctail substitutions. Our data indicate that phosphorylation sites in the IL3 and Ctail domains mediate and regulate αsub.1B-adrenergic receptor function. Phorbol ester-induced desensitization seems to be closely associated with receptor phosphorylation, whereas noradrenaline-induced desensitization likely involves other elements.
Phthalate esters are one of the most frequently detected persistent organic pollutants in the environment. A better understanding of their occurrence and degradation in the environment and during ...wastewater treatment processes will facilitate the development of strategies to reduce these pollutants and to bioremediate contaminated freshwater and soil. Phthalate esters occur at measurable levels in different environments worldwide. For example, the concentrations of dimethyl phthalate (DMP) in atmospheric particulate matter, fresh water and sediments, soil, and landfills are N.D.–10.4ng/m3, N.D.–31.7μg/L, N.D.–316μg/kg dry weight, and N.D.–200μg/kg dry weight, N.D.–43.27μg/L, respectively. Bis(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DBP) are primary phthalate ester pollutants. Urbanization has increased the discharge of phthalate esters to atmospheric and aquatic environments, and the use of agricultural plastics has exacerbated soil contamination by phthalate esters in rural areas. Aerobic biodegradation is the primary manner of phthalate ester mineralization in the environment, and this process has been widely studied. Phthalate esters can be removed during wastewater treatment processes. The combination of different wastewater treatment technologies showed greater efficiency in the removal of phthalate esters than individual treatment steps, such as the combination of anaerobic wastewater treatment with a membrane bioreactor would increase the efficiency of phthalate ester removal from 65%–71% to 95%–97%. This review provides a useful framework to identify future research objectives to achieve the mineralization and elimination of phthalate esters in the environment.
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•Occurrence of phthalate esters was summarized in the different environments.•Urbanization exacerbated the discharge of phthalate esters to atmosphere and water.•Aerobic biodegradation is the primary mineralization process of phthalate ester.•Phthalate esters could be removed by biodegradation and absorption in WWTPs.
Twenty-four new phenylpropanoid esters of sucrose, phanerosides A–X (1–24), were isolated from an EtOH extract of the rattans of Phanera championii Benth. (Fabaceae). Their structures were elucidated ...on the basis of comprehensive spectroscopic data analysis. A wide range of structural analogues were presented due to the different numbers and positions of acetyl substituents and the structures of phenylpropanoid moieties. Phenylpropanoid esters of sucrose were isolated from the Fabaceae family for the first time. Biologically, the inhibitory effects of compounds 6 and 21 on NO production in LPS-induced BV-2 microglial cells were better than that of the positive control, with ICsub.50 values of 6.7 and 5.2 μM, respectively. The antioxidant activity assay showed that compounds 5, 15, 17, and 24 displayed moderate DPPH radical scavenging activity, with ICsub.50 values ranging from 34.9 to 43.9 μM.
![Domino Aza-Michael-S[sub.N]...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/1420-3049/small "Domino Aza-Michael-S[sub.N]Ar-Heteroaromatization Route to C5-Substituted 1-Alkyl-1IH/I-Indole-3-Carboxylic Esters")
![Synthesis of [alpha], omega...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/0959-8103/small "Synthesis of [alpha], omega -isocyanate telechelic polymethacrylate soft segments with activated ester side functionalities and their use for polyurethane synthesis")
![Roles of the α[sub.1B]-Adre...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/1422-0067/small "Roles of the α[sub.1B]-Adrenergic Receptor Phosphorylation Domains in Signaling and Internalization")
