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The base promoted three-component reaction of β-enamino imide, malononitrile and various cyclic α-diketones in acetonitrile showed interesting molecular diversity. The reactions with acenaphthylene-1,2-dione and ninhydrin afforded functionalized spiro[indene-2,4'-pyrrolo[3,4- b]pyridines] and spiro[acenaphthylene-1,4'-pyrrolo[3,4- b]pyridines] in good yields. The similar reaction of phenanthrene-9,10-dione resulted in the formation of the unexpected complex phenanthro[9',10':4,5]furo[2,3- c]pyrrolo[3,4- b]pyrroles in satisfactory yields. [ABSTRACT FROM AUTHOR]

The novel 1,2-diaryl substituted pyrrolo[3,4- b]pyridine-5,7-diones were selectively synthesized in high yields by the base catalyzed cyclization reaction of 3-arylamino-1-methyl-1 H-pyrrole-2,5-diones with cinnamaldehyde and its derivatives in acetonitrile at room temperature. However, when piperidinium trifluoroacetate was employed as catalyst, the reaction afforded a mixture of 1,2-diaryl and 1,4-diaryl substituted pyrrolo[3,4- b]pyridine-5,7-diones in comparable yields. [ABSTRACT FROM AUTHOR]

The base mediated cycloaddition reactions of 4-dimethylamino-1-phenacylpyridinium bromides with two molecular 3-phenacylideneoxindoles in methylene dichloride afforded functionalized dispirocyclopentyl-3,3′-bisoxindoles in good yields and with high diastereoselectivity. The similar cycloaddition reactions of 1-( N, N-dialkylcarbamoylmethyl) and 1-cyanomethyl 4-dimethylamino-pyridinium bromide in refluxing ethanol in the presence of triethylamine also resulted in dispirocyclopentyl-3,3′-bisoxindoles with high diastereoselectivity. The stereochemistry of dispirocyclopentyl-3,3′-bisoxindoles was elucidated on the basis of 1H NMR data and single crystal structures. [ABSTRACT FROM AUTHOR]

Abstract: A fluorescent chemosensor for paeonol based on tetramethoxy resorcinarene tetraoxyacetic acid (TRTA) in hexadecyltrimethylammonium bromide (CTAB) medium was investigated. The fluorescence of TRTA was quenched by paeonol due to the formation of weak fluorescent inclusion complex (Paeonol–TRTA), and the fluorescence quenching (ΔF = F TRTA − F Paeonol–TRTA) was sensitized in CTAB. Under the optimal conditions, the linear range of calibration curve for the determination of paeonol was 0.02–6.40μg/mL. The detection limit estimated and RSD was 12.05ng/mL, 2.57% (n =3, c =1.0μg/mL). The mechanism of determination was discussed by quenching type analysis, absorption spectrum titrations, Benesi–Hildebrand method, fluorescence quantum yield and IR spectra. This method has also been applied for the determination of paeonol in real sample with satisfactory result. [Copyright &y& Elsevier]

Abstract: A series of aryl pyrogallol[4]arenes were efficiently synthesized in excellent yields by cyclocondensation of pyrogallol with aromatic aldehydes under microwave irradiation. The structures of aryl pyrogallol[4]arenes were confirmed by characterization of their acylated derivatives. Under microwave irradiation, alkylation reactions of aryl pyrogallol[4]arenes with some alkylating reagents such as n-butyl iodide, benzyl chloride, and ethyl α-chloroacetate were also finished quickly to yield fully O-alkylated products. The 1H NMR spectra and crystal structures showed that the acylated and alkylated aryl pyrogallol[4]arenes existed mainly in rctt (cis–trans–trans) configuration. [Copyright &y& Elsevier]

An approach for the synthesis of calixarene derivatives 3a–d, which contain ethylene glycol ether units at the lower rim in moderate yields, is described. The above compounds have been achieved by treating p-Butylcalix[n]arenes 1a–b(n = 6, 8) with chloroacetate 2a–b of 2-methoxyethanol and 2-(2-butoxyethoxy)ethanol in the system of K2CO3/KI/acetone. [ABSTRACT FROM AUTHOR]

[17] In this context, the development of efficient and mild methods for indole borylation has attracted increasing attention for research on the preparation of complex indoles. Although the use of a 1-adamantanoyl group can provide the desired indole C-H borylation products with high reactivity and selectivity, removing the directing group requires additional steps (Figure 4). Keywords: C-H bond activation; borylation; indoles; BBr 3; site selectivity; metal-free reaction EN C-H bond activation borylation indoles BBr 3 site selectivity metal-free reaction 2220 2226 7 10/31/23 20231127 NES 231127 Graph The indole ring system is one the most common heterocycles, present in many natural products and pharmaceuticals. [22] C2-Borylated indoles are versatile synthetic intermediates used to build 2,3-disubstituted indole skeletons as key intermediates in total syntheses of natural products and pharmaceuticals (Figure 1 A). [Extracted from the article]

Metal‐catalyzed C−H activation strategies provide an efficient approach for synthesis by minimizing atom, step, and redox economy. Developing milder, greener, and more effective protocols for these strategies is always highly desirable to the scientific community. In this study, the utilization of a single rhodium complex enabled the visible‐light‐induced late‐stage C−H activation of biaryl‐type phosphines with alkynyl bromides, employing inherent phosphorus atoms as directing groups. This chemistry combines P(III)‐directed C−H activation with visible light photocatalysis, under exogenous photosensitizer‐free conditions, offering a unique platform for ligand design and preparation. Furthermore, this study also explores the asymmetric catalysis and coordination chemistry of the resulting P‐alkyne hybrid ligands with specific transition metals. Experimental results and density functional theory calculations demonstrate the mechanistic intricacies of this transformation. [ABSTRACT FROM AUTHOR]

Metal‐catalyzed C−H activation strategies provide an efficient approach for synthesis by minimizing atom, step, and redox economy. Developing milder, greener, and more effective protocols for these strategies is always highly desirable to the scientific community. In this study, the utilization of a single rhodium complex enabled the visible‐light‐induced late‐stage C−H activation of biaryl‐type phosphines with alkynyl bromides, employing inherent phosphorus atoms as directing groups. This chemistry combines P(III)‐directed C−H activation with visible light photocatalysis, under exogenous photosensitizer‐free conditions, offering a unique platform for ligand design and preparation. Furthermore, this study also explores the asymmetric catalysis and coordination chemistry of the resulting P‐alkyne hybrid ligands with specific transition metals. Experimental results and density functional theory calculations demonstrate the mechanistic intricacies of this transformation. [ABSTRACT FROM AUTHOR]

Described herein is a visible‐light photoredox‐catalyzed regioselective 1,4‐hydroalkylation of 1,3‐enynes. Various of di‐ and tri‐substituent allenes were really accessible under the present reaction conditions. The visible‐light photoredox activation of the carbon nucleophile to generate its radical species, allowing the addition with un‐activated enynes. The synthetic utility for the present protocol was demonstrated by a large‐scale reaction, as well as the derivatization of the allene product. [ABSTRACT FROM AUTHOR]

An abstract of the article "Synthesis of dispirocyclopentyl-3,3'-bisoxindoles through domino cycloaddition reactions of 4-dimethylaminopyridinium bromides with 3-phenacylideneoxindoles," by L. Lu, C. Yan and J. Chin is presented.

Water-soluble [3]pseudorotaxane with enhanced fluorescence emission was successfully constructed and applied in cell imaging and photodynamic cancer therapy. [ABSTRACT FROM AUTHOR]

A novel fluorescent chemosensor of the derivatives of calix[4]arene (SAX) for Congo red (CR) in methyl-β-cyclodextrin/Triton X-100 synergistic sensitized system was developed. The results showed that the fluorescence intensity of SAX could be quenched by CR, and the fluorescence quenching (∆F = FSAX − FCR-SAX) was synergistic sensitized by methyl-β-CD and Triton X-100. Under the conditions of λex/em = 332/468 nm and pH 7.5, the linear range and the detection limit for CR were found to be 0.040-8.0 μg/mL and 8.9 ng/mL, respectively. The mechanism of determination was discussed by quenching type analysis and sensitizing effect. This method has also been applied for the determination of CR in beef samples with satisfactory results. [ABSTRACT FROM AUTHOR]

Visible‐light mediated hydrophosphorylation and hydrophosphorylative cyclization reactions using heterogeneous graphitic carbon nitride as the photocatalyst were described. The phosphorus atom radical was generated and allows the radical addition and addition/cyclization sequence, efficiently resulting in the final phosphorylated alkenes and cycles formation. Recyclable, nontoxic and low‐cost heterogeneous graphitic carbon nitride as visible light photocatalyst provides a new opportunity for the hydrophosphorylation and hydrophosphorylative cyclization reactions under the present redox‐neutral conditions. [ABSTRACT FROM AUTHOR]

The three-component reaction of N-phenacylbenzothiazolium bromides, aromatic aldehydes and indane-1,3-dione in ethanol at room temperature in the presence of triethylamine as base afforded functionalized spiro[benzo[ d]pyrrolo[2,1- b]thiazole-3,2′-indenes] in good yields and with high diastereoselectivity. The 1H NMR data and single crystal structure clearly indicated that the obtained spiro compounds predominately have one diastereoisomer. [ABSTRACT FROM AUTHOR]

The novel spirooxindoline fused [1,3]oxazines were efficiently synthesized from Diels-Alder reaction of N-arylmaleimides with 1,2-dihydro-2-oxospiro[3 H-indole-3,2′-[2 H,9a H-pyrido[2,1- b][1,3]oxazines], which were generated in situ from three-component reactions of substituted pyridines and isatins with methyl propiolate, or dimethyl acetylenedicarboxylate. The stereochemistry of the products was clearly clarified by the analysis of 1H NMR data and single crystal structures of the obtained polycyclic compounds. [ABSTRACT FROM AUTHOR]

A novel surfactant sensitized fluorescent chemosensor for safranine T (ST) based on calixarene-1,3-diacyl hydrazone (CADH) in sodium dodecyl sulfate (SDS) medium was investigated. The fluorescence intensity of CADH was quenched by ST due to the formation of weak fluorescent inclusion complex (ST-CADH), and the fluorescence quenching (Δ F = F CADH − F ST-CADH ) was sensitized in SDS. Under the optimal conditions, the linear range of calibration curve for the determination of ST was 0.02–3.00 μg/m and the detection limit estimated 0.015 μg/mL with RSD 2.2% ( n = 3, c = 1.0 μg/mL). The mechanism of determination was discussed with the fluorescence quenching type, the inclusion of CADH with ST and surfactant sensitized effect. This method has been applied for the detection of ST in real samples with satisfactory results. [ABSTRACT FROM AUTHOR]

The one-pot sequential reaction of arylamines, methyl propiolate and 2-aryl-3-nitrochromenes without any catalyst in refluxing ethanol afforded the polysubstituted 3-(3-nitro-2-phenylchroman-4-yl)-3-arylaminoacrylates in good yields and with high diastereoselectivity. Reaction mechanism was believed involving the initial formation of β-enamino ester and sequential Michael addition. [ABSTRACT FROM AUTHOR]

Highlights: [•] A simple and sensitive calix[4]arenes fluorescence quenching method for the ST. [•] The fluorescence of TRCA could be quenched by ST. [•] ΔF = F TRCA − F ST-TRCA was sensitised in CTAB. [•] The proposed procedure was applied to the determination of ST in food samples with satisfactory results. [Copyright &y& Elsevier]

An efficient synthetic procedure for the functionalized spiro[furan-3,3′-indoline] derivatives was successfully developed by domino reactions of N-phenacylpyridinium bromides or N-ethoxycarbonylmethylenepyridinium bromide with isatinylidene acetoacetate in the presence of triethylamine in ethanol at room temperature. The mechanism included sequential Michael addition of the in situ generated pyridinium ylide and intramolecular substitution of enolate. [ABSTRACT FROM AUTHOR]

A series of large macrocyclic calixarene bishydrazones were efficiently synthesized by [2+2] condensation reactions of calix[4]arene 1,3-disubstituted aldehydes with hydrated hydrazine. The X-ray single crystal diffraction showed that macrocycles form a distinctive calixtube-liking shape. [ABSTRACT FROM AUTHOR]

A series of salicylidenimine functionalized p-tert-butylcalix[n]arene-core dendrimers 7a-b were synthesized in higher yields by divergent method from the corresponding ethyl p-butylcalix[n]arylacetates 2a-b (n = 6, 8). 2a-b were first treated with excess of 1,6-diaminohexane to give amide derivatives with free amine terminal groups 3a-b, which in turn reacted with salicylaldehyde in alcohol to yield the first generation of Schiff bases 4a-b. 3a-b reacted with ethyl acrylate, ammonolized with 1,6-diaminohexane and condonsated with salicylaldehyde successfully to give the second generation of Schiff bases 7a-b. The extraction and binding properties of the dentritic Schiff bases 4a-b and 7a-b for several kinds of metal ions were studied with UV-Vis spectroscopy and atomic absorption spectroscopy. In which they showed a great affinity for soft Cu2 + ions and formed 1:1 or 1:2 stoichiometric complexes. [ABSTRACT FROM AUTHOR]

Thiourea‐bridged peracetylated glycoside calixarenes have been smoothly synthesized by the addition reactions of tetraacetylglycosyl isothiocyanates with amidoamine derivatives of calix[4]resorcinarene and p‐tert‐butylcalix[n]arenas ( n =6, 8) in high yields (40–75%). All the glycoside‐containing calixarenes were characterized by 1 H NMR, IR spectroscopy, and elemental analysis. [ABSTRACT FROM AUTHOR]

A three‐component acylation/peroxidation of alkenes through visible‐light photocatalysis was described. The acyl radical was generated by a hydrogen atom transfer process and enabled the radical addition and peroxidation. Various indole‐3‐carbaldehyde and styrene derivatives were subjected to the current visible light photochemical conditions, delivering β‐peroxy‐ketones in moderate to good isolated yields. [ABSTRACT FROM AUTHOR]

A "three‐components" supramolecular assembly has been fabricated by mixing 2, 2': 6', 2"‐terpyridine attached pillar[5]arene, cyano and triazole bearing alkyl chain and Zn2+ in solvent of CHCl3 and CH3CN. The driving forces for the assembly were believed to be host‐guest and metal chelating interactions as characterized by 1H NMR, UV‐vis and fluorescence spectra. The supramolecular organo‐gel formed upon the concentration of components amount to 1 M. The supramolecular displayed nitrobenzene based explosive sensing capability using picric acid, ortho‐nitrobenzene and phenol as samples. The assembly was most sensitive towards picric acid among the three analytes. The limit of detection for picric acid was determined to be 1.66 × 10−4 M. [ABSTRACT FROM AUTHOR]

We herein described a visible light induced nickel(II)-catalyzed cross-coupling of secondary phosphine oxides with aryl halides. The Ni(I) species and chlorine atom radical Cl˙ were generated via the ligand to metal charge transfer (LMCT) process of the NiCl2(PPh3)2, which allows nickel(IV)-phosphorus species in situ formation, giving various tertiary phosphine oxides under photocatalyst-free conditions. [ABSTRACT FROM AUTHOR]

A new type of supramolecular polymeric material was constructed efficiently via orthogonal pillar[5]arene-based host–guest and hydrogen bond interactions. The supramolecular polymeric materials prove to be a good catalyst for the Fenton reaction in water. [ABSTRACT FROM AUTHOR]

Described herein is a visible‐light‐mediated atom‐transfer radical cyclization (ATRC) using 1,6‐enynes as substrates. The sulfonyl chlorides not only served as sulfonyl radical sources but also provided a chlorine atom to enable the formation of highly functionalized cyclic products. This visible‐light‐mediated photocatalytic method is a mild and practical strategy for synthesizing chloroalkyl‐substituted cyclic alkenyl sulfones. [ABSTRACT FROM AUTHOR]

Abstract The fluorinative alkoxylation of simple alkenes under catalyst-free conditions was achieved. Various substituted olefins, including terminal and internal alkenes, and oxygen-containing nucleophiles were compatible with the standard conditions, and gave a variety of β-fluoroethers in good to excellent yields. Notably, the alkynyl and chloride-containing nucleophiles were well tolerated. In addition, acetic acid and TsNH 2 could be also used as nucleophiles and successfully afforded the desired products in good yields. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

A diagram is presented which shows the chemical structure of the synthesis of spiro[benzo[d]pyrrolo[2,1-b]thiazole-3,2'-indenes] derrivatives through three-component reaction.

The title compounds are obtained as mixture of cis/trans-isomers. [ABSTRACT FROM AUTHOR]

The novel spirooxindoline fused [1,3]oxazines (V) and (VI) are efficiently synthesized by an one-pot two-step domino reaction, which involves the sequential formation of a Huisgens 1,4-dipole, 1,4-dipolar cycloaddition and a Diels-Alder reaction. [ABSTRACT FROM AUTHOR]

In this work, a novel and simple flexible aromatic multi-carboxylate compound N, N′-(4,4′-biphenylyl) iminodiacetic acid (BP-IDA) was synthesized, with which two new stable metal-IDA gels (denoted as MIG1 and MIG2) with three-dimensional network structures have been prepared successfully by employing Cr3+ and Al3+ as the metal ions, respectively. The rheological performance was investigated by means of dynamic rheology measurement. The morphology and microstructure were characterized by scanning electron microscopy, transmission electron microscopy, and X-ray diffraction technique. Nitrogen sorption isotherm measurement suggests that the MIG1 aerogel has considerable porosity with the Brunauer-Emmett-Teller specific surface area up to 760 m2·g−1. Owing to easy preparation, good stability, and three-dimensional network structure, the as-prepared metal-organic gels will possess potential applications in separation, catalysis, and drug delivery. [ABSTRACT FROM AUTHOR]

• A medium-strength complex was formed between P5SB and MB. • The amphiphilic P5SB⊃MB complex assembled into stable vesicles at pH=7.4. • The anti-cancer efficiency of DOX-loaded P5SB⊃MB vesicles was significantly enhanced. • The live-cell imaging property of DOX was maintained after encapsulation. Cocktail therapy is one of the leading approaches for treating some complex diseases. Herein, a pH-triggered supramolecular cocktail drug delivery system assembled by the medium-strength complexes of pillar[5]arene-based Schiff base (P5SB) with methylene blue (MB). Molecular modeling suggest that noncovalent interactions between Schiff base side chain of P5SB and MB were mainly responsible for the stability of the complex. The amphiphilic P5SB⊃MB complex assembled into stable vesicles with an average diameter of 244.1 nm in conventional physiological environment (pH=7.4). Drug loading experiments demonstrated that doxorubicin (DOX) could be efficiently encapsulated into the hollow vesicles, and the drug would be rapidly released under acidic environment (pH=6.0). Moreover, the anti-cancer efficiency of DOX-loaded P5SB⊃MB vesicles was significantly enhanced because of the synergistic effect of P5SB, MB and DOX. Nonetheless, the live-cell imaging property of DOX was maintained after encapsulation. [Display omitted] [ABSTRACT FROM AUTHOR]

The one-pot four-component reaction of benzohydrazide, acetylenedicarboxylate, aromatic aldehydes and malononitrile in ethanol with triethylamine as base catalyst afforded functionalized 1-benzamido-1,4-dihydropyridines in satisfactory yields. Under similar conditions, picolinohydrazide or nicotinohydrazide can also be successfully utilized in the reactions to give corresponding functionalized 1,4-dihydropyridines. 1H NMR data indicated that an equilibrium of cis/trans-conformations exist in 1-benzamido-1,4-dihydropyridines. [ABSTRACT FROM AUTHOR]

The title compounds (IV) (12 examples) are obtained with high diastereoselectivity and without any catalyst. [ABSTRACT FROM AUTHOR]

The article presents chemical equations related to the article "Efficient Synthesis of Spiro[furan-3,3'-indoline] Derivatives via Reactions of Pyridinium Salts with Isatinylidene Acetoacetates" by researchers J. Fang, C. Yan and Z. Liu published in the "Chinese Journal of Chemistry" in 2013.

In the presence of zinc chloride, the in situ generated β-enamino ester from the reaction of morpholine, piperidine and pyrrolidine with methyl propiolate reacted, with aromatic aldehydes and thiourea in ethanol resulting in the functionalized tetrahydropyrimidin-2-thiones in satisfactory yields and with good diastereoselectivity. When aromatic aldehydes bearing electron-withdrawing group were used in the reaction, the 4-hydroxytetrahydropyrimidin-2-thione derivatives were obtained as the main product. [ABSTRACT FROM AUTHOR]

Alternatively to dimethyl acetylenedicarboxylate (II), the corresponding diethyl esters can be used as well. [ABSTRACT FROM AUTHOR]

The functionalized arylidene bis(3-arylaminoacrylates) were efficiently prepared by FeCl3 catalyzed one-pot domino reactions of primary amines, methyl propiolate and aromatic aldehydes. When isatins were utilized under similar conditions, only 2-oxoindolinyl 3-arylaminoacrylates were obtained in moderate yields. 1H NMR data and single crystal structures indicated that this reaction has high diastereoselectivity. [ABSTRACT FROM AUTHOR]

Under the catalysis of Lewis acid Co(ClO4)2 the reaction of the sterically hindered 1,1,2,3-tetrasubstituted cyclopropanes with arylamines in refluxing THF gave the functionalized 2-aminopyrroles with sequential ring-opening of cyclopropane, nucleophilic substitution, nucleophilic addition of cyano group and recyclization processes. [ABSTRACT FROM AUTHOR]

An efficient synthetic procedure for the functionalized spiro[indoline-3,4′-pyridine] was developed via the four-component reactions of arylamines, acetylenedicarboxylates, isatins and malononitrile with triethylamine as the base catalyst. The advantages of this reaction are using common starting material, mild reaction conditions, broad scope of reactants and operational simplicity. [ABSTRACT FROM AUTHOR]

In this article, a new result of the reaction of 6-aminouracil with aldehyde catalyzed by BF3 and aniline is established, which gives a new strategy for the synthesis of di(6-aminouracil-5-yl)-arylmethane. The simple and convenient synthetic procedure and formation of di(6-aminouracil-5-yl)-arylmethane render this method very useful in synthetic and medicimal chemistry. [ABSTRACT FROM AUTHOR]

A multicomponent synthesis of highly substituted pyrroles catalyzed by thiazolium salts has been disclosed. The reaction employs an acyl anion conjugate addition reaction of aldegyde and unsaturated ketones to generate 1,4-dicarbonyl compounds in situ. The subsequent addition of various amines promotes a Paal-Knorr reaction, affording the desired pyrrole nucleus in an efficient one-pot process. [ABSTRACT FROM AUTHOR]

An efficient method has been successfully developed for the synthesis of oxygen-bridged pyrimidine tricyclic derivatives from salicylaldehyde, ethyl acetoacete, and urea catalyzed by PdO in very good yield. A series of different oxygen-bridged pyrimidine tricyclic derivatives has been synthesized, in which two compounds' x-ray crystal structure were obtained. [ABSTRACT FROM AUTHOR]

A simple and convenient one-pot procedure is reported for the synthesis of 1,2-diketones from corresponding benzoin-type condensation reaction of aromatic aldehydes in water with N,N-dialkylbenzimidazolium salt as condensation catalyst and ferric chloride as oxidizing reagent. [ABSTRACT FROM AUTHOR]

A high‐yielding one‐pot procedure for the generation of 2‐substituted benzimidazoles first from esters using a microwave procedure is described. [ABSTRACT FROM AUTHOR]

Treatment of aryl ketones with p‐toluenesulfinic acid and a catalytic amount of tin tetrachloride anhydrous (5%) in 1‐pentanol gives good yields of 1,3,5‐triarylbenzenes. [ABSTRACT FROM AUTHOR]

A number of benzodioxane compounds were synthesized using the palladium-catalyzed etherification of aryl halides by employing triphenylphosphane ligands. This method was used as key step in the synthesis of two natural products isoamericanol A and isoamericanin A. [ABSTRACT FROM AUTHOR]

To date, the knowledge about the properties of calixarene-based surfactants have been limited although it is hypothesized that the calixarene framework may endow calixarene-based surfactants with unique properties. In the present study, the adsorption and micellization behaviors of amphiphilic calix[4]resorcinarenes and their interactions with proteins were studied by various techniques, including surface tension measurement and fluorescence, UV–vis absorption, and 1H NMR spectroscopy; the amphiphilic calix[4]resorcinarenes were obtained by modifying tetramethoxyresorcinarenes with ammonium and imidazolium groups on the upper rim and alkyl groups on the opposite rim. We found that a tetramethoxyresorcinarene with a very short alkyl chain exhibited good surface activity and the critical micelle concentration (cmc) was much lower than that for the conventional surfactant having a long alkyl chain. Moreover, the cmc and saturated adsorption values (Γ max) decreased but the surface tension (γ) at the cmc (γ cmc) and single molecular cross-sectional area (A min) increased with increasing alkyl chain length. In the presence of proteins, the surface tension remained unchanged at less than stoichiometric tetramethoxyresorcinarene concentrations; however, at higher tetramethoxyresorcinarene concentrations, the surface tension began to decrease drastically, much faster than the case without protein. In addition, the binding of the tetramethoxyresorcinarene to the protein increased the protein activity, and the degree of enhancement in the protein activity was closely related to the protein structure. The molecular simulations further explained the binding modes of the tetramethoxyresorcinarenes to the protein. • Tetramethoxyresorcinarene-based cationic surfactant exhibited good surface activity. • γ with protein remained unchanged at less than stoichiometric tetramethoxyresorcinarene concentrations. • Protein made γ decreased much faster in a proper range of tetramethoxyresorcinarene content. • The tetramethoxyresorcinarene increased protein activity. • The degree of enhancement in protein activity was related to protein structure. [ABSTRACT FROM AUTHOR]