Amphiphilic Compounds Research Articles

Amphiphilic stilbene derivatives attenuate the neurotoxicity of soluble Aβ42 oligomers by controlling their interactions with cell membranes.

The misfolded proteins or polypeptides commonly observed in neurodegenerative diseases, including Alzheimer's disease (AD), are promising drug targets for developing therapeutic agents. To target the amyloid-β (Aβ) peptide plaques and oligomers, the hallmarks of AD, we have developed twelve amphiphilic small molecules with different hydrophobic and hydrophilic fragments. In vitro fluorescence binding assays demonstrate that these amphiphilic compounds show high binding affinity to both Aβ plaques and oligomers, and six of them exhibit selective binding toward Aβ oligomers. These amphiphilic compounds can also label the Aβ species in the brain sections of transgenic AD mice, as shown by immunostaining with an Aβ antibody. Molecular docking studies were performed to obtain structure-affinity relationships. To our delight, four amphiphilic compounds can alleviate the Cu2+-Aβ induced toxicity in cell viability assays. In addition, confocal fluorescence imaging studies provide evidence that two compounds, ZY-15-MT and ZY-15-OMe, can disrupt the interactions between Aβ oligomers and human neuroblastoma SH-SY5Y cell membranes. Overall, these studies strongly suggest that developing compounds with amphiphilic properties that target Aβ oligomers and modulate the Aβ oligomer-cell membrane interactions can be an effective strategy for the development of small molecule AD therapeutics.

BIOSURFACTANT PRODUCTION BY ENDOPHYTIC ISOLATES FROM RHIZOMES OF ZINGIBER ZERUMBET

Biosurfactants (BS) or green surfactants are amphiphilic compounds that enhance the bioavailability of hydrophobic organic compounds and also exhibit anti-phytopathogenic properties. BSproducing isolates thus find applications in soil remediation and development of biocontrol agents. Endophytes that confer several benefits to host plant constitute a good resource for prospecting BSproducing isolates. The present study screened the Z. zerumbet endophytes identified in earlier studies for BS production by hydrocarbon overlay agar method, CTAB- Methylene blue agar assay and determining Emulsification Index (EI24). EI24 was observed as the most desirable parameter to determine BS production compared to hydrocarbon overlay agar and CTAB- methylene blue agar plate assay. Isolate ZzADK4 (Bacillus spp) showed highest emulsification activity (58%) determined as EI% with kerosene. UV-vis spectral scans identified the endophytes as producing LP class of BS with absorbance maxima spanning 207- 216 nm. LP class of BS producing endophytic isolates identified in the present study constitute potential solutions with applications in soil remediation and the development of biocontrol agents (BCAs).

Stimuli-responsive assembly of bilingual peptide nucleic acids.

Peptide nucleic acids (PNAs) are high-affinity synthetic nucleic acid analogs capable of hybridization with native nucleic acids. PNAs synthesized having amino acid sidechains installed at the γ-position along the backbone provide a template for a single biopolymer to simultaneously encode nucleic acid and amino acid sequences. Previously, we reported the development of “bilingual” PNAs through the synthesis of an amphiphilic sequence featuring separate blocks of hydrophobic and hydrophilic amino acid functional groups. These PNAs combined the sequence-specific binding activity of nucleic acids with the structural organization properties of peptides. Like other amphiphilic compounds, these γ-PNAs were observed to assemble spontaneously into micelle-like nanostructures in aqueous solutions and disassembly was induced through hybridization to a complementary sequence. Here, we explore whether assembly of these bilingual PNAs is possible by harnessing the nucleic acid code. Specifically, we designed an amphiphile-masking duplex system in which spontaneous amphiphile assembly is prevented through hybridization to a nucleic acid masking sequence. We show that the amphiphile is displaced upon introduction of a releasing sequence complementary to the masking sequence through toehold mediated displacement. Upon release, we observe that the amphiphile proceeds to assemble in a fashion consistent with our previously reported structures. Our approach represents a novel method for controlled stimuli-responsive assembly of PNA-based nanostructures.

Synthesis and fungicidal activity of alkyltrimethylammonium salicylate ionic liquids

Three alkyltrimethylammonium salicylates (CnTASal) with different alkyl side chains were synthesized and characterized. Solubility, surface activity, and biological activity of the ionic liquids were determined. The results of solubility and surface activity showed that the synthesized ILs are amphiphilic surface-active compounds. Five common agricultural fungi, Valsa mali, Rhizoctonia solani, Fusarium graminearum, Phytophthora capsica and Alternaria solani were tested to identify the most sensitive strain and Valsa mali was selected for the structure-activity relationship (SAR) study. The results of the study revealed that the antifungal activity of the ILs is positively related to the alkyl chains length.

Evolution of modern age drug discovery of lipopeptides and computer-aided drug discovery in India

The endeavor has been attempted to present a review on the evolution of modern age drug discovery in India. The contribution of next generation therapeutics options microbial metabolites and the computational drug discovery aspects to the global market from India have been represented. Microbial metabolites such as lipopeptides and peptide therapeutics are gaining worldwide importance due to their multiple applications as broad-spectrum antimicrobial, antiviral, anticancer properties etc. Due to the surge of microbial resistance, tumor resistance, and ongoing pandemic due to constantly mutating corona virus, there is a need to develop next-generation therapeutics options from natural origin, less toxic to the environment, and have higher specificity towards target. Small molecule therapeutics are certainly less specific towards cancer targets hence the cytotoxicity is a major issue in cancer treatment while drug resistance due to the mutations are coming as challenges every day for drug discovery researchers. Microbial lipopeptide reserves a sweet spot in between the small molecule inhibitors and peptide therapeutics because of their amphiphilic compounds consist of a fatty acid side chain and a cyclic peptide moiety of hydrophilic nature. The computational drug discovery approach accelerates the drug discovery process due to the advancement in supercomputer facilities provided by various funding agencies such as the Department of Biotechnology (DBT) and the Department of Science and Technology (DST) in India. The current review article is focusing light on the research contribution of Indian Scientists and Govt. of India in the field of lipopeptide-based research and applications of Computer-aided drug discovery.

Supramolecular self-associating amphiphiles: determination of molecular self-association properties and calculation of critical micelle concentration using a high-throughput, optical density based methodology.

Supramolecular self-associating amphiphiles are a class of amphiphilic salt, the anionic component of which is 'frustrated' in nature, meaning multiple hydrogen bonding modes can be accessed simultaneously. Here we derive critical micelle concentration values for four supramolecular self-associating amphiphiles using the standard pendant drop approach and present a new high-throughput, optical density measurement based methodology, to enable the estimation of critical micelle concentrations over multiple temperatures. In addition, we characterise the low-level hydrogen bonded self-association events in the solid state, through single crystal X-ray diffraction, and in polar organic DMSO-d6 solutions using a combination of 1H NMR techniques. Moving into aqueous ethanol solutions (EtOH/H2O or EtOH/D2O (1 : 19 v/v)), we also show these amphiphilic compounds to form higher-order self-associated species through a combination of 1H NMR, dynamic light scattering and zeta potential studies.

Multi analyte sensing of amphiphilic tridentate bis(benzimidazolyl)pyridine incorporated in liposomes and potential application in enzyme assay.

A liposome based nanosensor Lipo-1 for efficient detection of copper, cyanide (CN-) and ATP in a pure aqueous medium has been described. Lipo-1 shows a fluorescence ON-OFF response with copper. However, Lipo-1.Cu (Lipo-1 and copper ensemble) was used for the OFF-ON detection of ATP with nM and CN- with μM detection levels, lower than the WHO permissible level for safe drinking. Lipo-1 has better and enhanced binding properties over the counter organic amphiphilic compound Bzimpy-LC, which is not soluble in water. The significant changes in the emission spectra in the presence of Cu2+, CN- and ATP ions, as variable inputs, are used to construct INHIBIT and OR logic operations in a nano-scale environment. The fluorescent detection of CN- ions with Lipo-1.Cu was used to develop an enzyme assay for β-glucosidase using amygdalin as the substrate. β-Glucosidase enzymatic activity was monitored by the emission OFF-ON signal of the probe Lipo-1.Cu by CN- detection. This approach could be an efficient method for developing a fluorescence-based β-glucosidase enzyme assay. A switch ON luminescence response, low detection limit, fast response, 100% aqueous solution, biocompatibility, multi-analyte detection, and improved sensitivity and selectivity of Bzimpy-LC in lipid bilayer membranes are the main features of the nanoprobe Lipo-1. These properties give it a clear advantage for analytical applications.

CHARACTERIZATION OF THE PHYSICOCHEMICAL PROPERTIES OF THE BIOSURFACTANT PRODUCED BY L. ACIDOPHILUS AND L. PENTOSUS

Biosurfactants or surface-active compounds are biodegradable, non-toxic and eco-friendly compounds released by microorganisms. Biosurfactants are amphiphilic compounds cause surface tension reduction both aqueous solutions and hydrocarbon mixtures. The main purpose of this work was to characterize biosurfactant produced by Lactobacillus strains. Identification using 16s rDNA identified the isolates as L. acidophilus for Fm1 and L. pentosus for Y1. Effect different parameters (temperature, PH and Salinity) were studied to evaluate the stability of biosurfactant after treatment. In addition, critical micelle concentration of biosurfactant, emulsification index and viscosity reduction of palm and engine oils have been studied. The results revealed that, the biosurfactant from L. acidophilus and L. pentosus maintains its emulsifications activities unaffected in the wide range of parameter's study except slightly decreasing in emulsification index values at salinity 15%. The maximum reduction in surface tension was 18.05 mN/m with minimum concentration of critical micelle concentration of 7.5 mg/ml and high decrease of palm and engine oil viscosity of 110.1 and 165.3% respectively. This study concluded that, the emulsification activity, the surface activity and the stability to heat treatment, different PH and salinity of biosurfactant of Lactobacillus strains revealed the application of the biosurfactant in food, pharmaceutical, cosmetics industries and oil recovery.

Tapping the Role of Microbial Biosurfactants in Pesticide Remediation: An Eco-Friendly Approach for Environmental Sustainability.

Pesticides are used indiscriminately all over the world to protect crops from pests and pathogens. If they are used in excess, they contaminate the soil and water bodies and negatively affect human health and the environment. However, bioremediation is the most viable option to deal with these pollutants, but it has certain limitations. Therefore, harnessing the role of microbial biosurfactants in pesticide remediation is a promising approach. Biosurfactants are the amphiphilic compounds that can help to increase the bioavailability of pesticides, and speeds up the bioremediation process. Biosurfactants lower the surface area and interfacial tension of immiscible fluids and boost the solubility and sorption of hydrophobic pesticide contaminants. They have the property of biodegradability, low toxicity, high selectivity, and broad action spectrum under extreme pH, temperature, and salinity conditions, as well as a low critical micelle concentration (CMC). All these factors can augment the process of pesticide remediation. Application of metagenomic and in-silico tools would help by rapidly characterizing pesticide degrading microorganisms at a taxonomic and functional level. A comprehensive review of the literature shows that the role of biosurfactants in the biological remediation of pesticides has received limited attention. Therefore, this article is intended to provide a detailed overview of the role of various biosurfactants in improving pesticide remediation as well as different methods used for the detection of microbial biosurfactants. Additionally, this article covers the role of advanced metagenomics tools in characterizing the biosurfactant producing pesticide degrading microbes from different environments.

Green synthesis of environmentally benign collagen fibers-derived hierarchically structured amphiphilic composite fibers for high-flux dual separation of emulsion

Developing dual separation materials that exhibit high-flux separation capabilities towards oil-in-water (O/W) and water-in-oil (W/O) emulsions provides a promising and facile remediation strategy for the contamination caused by emulsified oily wastewater. Herein, environmentally benign amphiphilic composite fibers (ACFs) were facilely prepared by a green synthesis approach that relied on the non-covalent decoration of tannic acid (TA), the natural amphiphilic phenolic compound, onto collagen fibers (CFs) with inherent amphiphilicity and structural hierarchy. Hydrophobic interactions and multi-hydrogen bonding interactions between the amphiphilic TA and CFs brought the enhancement of amphiphilicity-enabled wetting behaviors as well as the structural stability of CFs. The green synthesized ACFs exhibited hydrophilicity, underwater superoleophobicity and underoil hydrophilicity. The as-prepared ACFs were directly utilized for the dual separation of O/W and W/O emulsions with high separation efficiency (> 99.99%) and high flux (e.g. 2471 L m−2 h−1) by selectively permeating the continuous water phase of O/W emulsions and the continuous oil phase of W/O emulsions, respectively. Compared with CFs, the structural stability of ACFs was improved significantly, which therefore provided appreciable reusability and long-term separation stability. Our findings demonstrated the essential role of amphiphilicity played in the dual separation of O/W and W/O emulsions, which also provided a new solution for the remediation of emulsified oily wastewater by developing biomaterials-based amphiphilic separation materials.

Experimental investigation on hydrate anti-agglomerant for oil-free systems in the production pipe of marine natural gas hydrates

During the production of marine natural gas hydrates, as gas hydrates are easily formed, they tend to agglomerate, deposit on the pipe walls, and eventually block the pipe. In this study, high-pressure autoclave and micromechanical force apparatus were used to investigate the effects of anti-agglomerants and kinetic inhibitors on the hydrate agglomeration in the oil-free gas–water system, and the anti-agglomeration mechanism was analyzed. The results indicate that when the hydrate conversion rate reached about 27%, a complete blockage occurred. In the oil-free system, conventional anti-agglomerants did not exhibit any anti-agglomeration performance; while kinetic inhibitors slowed down the hydrate formation, but could not inhibit their agglomeration. An amphiphilic amide compound, namely DCA, effectively prevented hydrate agglomeration and blockage under the simulated hydrate production conditions of 8-h stirring and subsequent 8-h shut-in. From the perspective of interparticle interaction, 1.0 wt% DCA reduced the cohesion force between cyclopentane hydrate particles by 62% and 70% in liquid cyclopentane and air, respectively. These effects were attributed to the adsorption of DCA on the surface of hydrate particles, which converted the surface characteristic from hydrophilic to hydrophobic; thus, no liquid bridge could be formed between particles. Moreover, DCA formed an isolating layer and offered steric hindrance, thus preventing the adhesion and agglomeration of hydrates.

Preparation and Properties of Ambidextrous Gelators Having Ethanolamine Moiety

AbstractAlthough tremendous research investigations on organogelators and hydrogelators have been conducted, the reports about the ambidextrous gelators capable of gelating both organic solvents, especially, apolar solvents and water are very limited. In order to create efficient ambidextrous gelators it should be necessary to take a bottom‐up approach. Thus, according to molecular design the amphiphilic compounds consisting of glutamate‐based structure having two long alkyl chains and the ethanolamine moiety have been prepared. The compounds having C6 and C7 alkyl chains have been found out to work as an excellent ambidextrous capability because they can only gelate water and apolar solvents. Although the compounds having C9 and C10 alkyl chain showed no gelation in water, by introduction of an ammonium cation into these compounds ambidextrous properties were gained. Ambidextrous ability can be imparted to the compound having no ambidextrous properties by mixing with a small amount of an authentic ambidextrous gelator.

Phosphonodithioester-Amine Coupling as a Key Reaction Step for the Design of Cationic Amphiphiles Used for Gene Delivery.

A convergent synthesis of cationic amphiphilic compounds is reported here with the use of the phosphonodithioester–amine coupling (PAC) reaction. This versatile reaction occurs at room temperature without any catalyst, allowing binding of the lipid moiety to a polar head group. This strategy is illustrated with the use of two lipid units featuring either two oleyl chains or two-branched saturated lipid chains. The final cationic amphiphiles were evaluated as carriers for plasmid DNA delivery in four cell lines (A549, Calu3, CFBE and 16HBE) and were compared to standards (BSV36 and KLN47). These new amphiphilic derivatives, which were formulated with DOPE or DOPE-cholesterol as helper lipids, feature high transfection efficacies when associated with DOPE. The highest transfection efficacies were observed in the four cell lines at low charge ratios (CR = 0.7, 1 or 2). At these CRs, no toxic effects were detected. Altogether, this new synthesis scheme using the PAC reaction opens up new possibilities for investigating the effects of lipid or polar head groups on transfection efficacies.

Amphiphilic distyrylbenzene derivatives as potential therapeutic and imaging agents for the soluble amyloid‐β oligomers in Alzheimer’s disease

AbstractBackgroundNew amphiphilic distyrylbenzene derivatives have been developed that target both the soluble Aβ oligomers and amyloid plaques in Alzheimer's disease (AD), as well as the extracellular p‐tau aggregates, Aβ‐mediated oxidative stress, and neuroinflammation.MethodWe have developed a novel amphiphilic distyrylbenzene derivative that exhibits high binding affinity for Aβ aggregates ‐ especially the Aβ oligomers, and a series of ex vivo and in vivo immunostaining and imaging studies were employed to probe the beneficial properties of this potential therapeutic agent.ResultUpon treatment of 5×FAD mice with an amphiphilic distyrylbenzene derivative, fluorescence imaging of the brain sections shows that this compound can easily penetrate the blood‐brain‐barrier and selectively bind to the Aβ oligomers, as confirmed by the colocalization with an Aβ oligomer‐specific antibody. Furthermore, when comparing the MFC‐treated mice vs. the vehicle‐treated mice, the total amount of Aβ species and the associated p‐tau aggregates was significantly decreased by up to 70%, along with a significant reduction in the amount of activated microglia.ConclusionThe amphiphilic distyrylbenzene compound reported herein can attenuate the formation of amyloid plaques and associated p‐tau aggregates, while also reducing the microglia‐mediated neuroinflammatory response, which is uncommon among the previously reported amyloid‐targeting chemical agents.

Bioemulsifiers

Bioemulsifier is a poly-anionic and amphiphilic compound which can balance out the hydrocarbon emulsion in water by making an extremely thin layer between the hydrocarbon beads and water. Most extreme focus is acquired when culture media containing 12 carbon-based unsaturated fats are utilized as the carbon source. Bioemulsifier with proficient emulsifying action and low-production cost, meets various prerequisites of emulsification in the most practical manner in numerous industrial sectors such as in food and dairy.

Electrophoretic mobility of ester betulin derivatives and their complexation with γ-cyclodextrin studied by capillary electrophoresis in aqueous solutions at different pH values.

In this article, capillary electrophoresis was used to measure the effective electrophoretic mobility of ester betulin derivatives as a pH function and to study their complexation with γ-cyclodextrin (γ-CD). The electrophoretic mobility of betulin 3,28-diphthalate (DPhB) and 3,28-disuccinate (DScB) changed unusually with decreasing pH: instead of decreasing, it first increased and then decreased. This fact as well as the turbidity of sample solutions at pH from 2.5 to 6, broadening of electrophoretic peaks and a decrease in the surface tension of the solutions indicates that these betulin derivatives, being amphiphilic compounds and weak acids, exist as micelles in aqueous solutions at pH 6 and below. The inclusion complexation of betulin derivatives with γ-CD at pH 9.18 and 4.5 was studied by mobility shift affinity capillary electrophoresis. At pH 9.18, the apparent binding (stability) constant logarithms for 1:1 γ-CD complexes of DPhB, betulin 3,28-disulfate (DSB) and DScB with 95% confidence interval limits were equal to 7.44± 0.02, 7.09 (7.01-7.19), and 6.97 (6.87-7.08) at 25°C, respectively. At pH 4.5, the binding constant for the DSB complex was slightly lower, while the micelle formation did not allow determining the exact values of the constants for the DPhB and DScB complexes.

Formation of pH-Responsive Supramolecular Hydrogels in Basic Buffers: Self-assembly of Amphiphilic Tris-Urea.

An amphiphilic tris-urea compound (1) containing hydrophilic resorcinol units was designed and synthesized. Compound 1 formed supramolecular hydrogels in basic buffers, such as glycine-NaOH, phosphate-NaOH, 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES)-NaOH, and borate-NaOH. The optimum pH range of the buffer solution for gelation was 10-11 and insoluble suspensions or solutions were formed when the pH was outside this range. When the borate-NaOH buffer was used, supramolecular hydrogels were formed over a wide pH range (7.5-11.0). The thermal stabilities and viscoelastic properties of the supramolecular hydrogels were determined from the gel-to-sol phase transition temperatures and rheological properties, respectively. The supramolecular hydrogel formed from compound 1 and the borate-NaOH buffer exhibited a pH-responsive reversible gel-to-sol phase transition property. Gel-to-sol phase transition could be achieved by adding NaOH and regelation of the sol was realized by adding an appropriate amount of boric acid. Increasing the amount of the acid resulted in a gel-to-sol phase transition.

Biodegradable Amphoteric Surfactants in Titration-Ultrasound Formulation of Oil-in-Water Nanoemulsions: Rational Design, Development, and Kinetic Stability.

Amphoteric amphiphilic compounds, due to their unique properties, may represent a group of safe and biocompatible surface-active agents for effective colloidal stabilization of nanoformulations. For this reason, the aim of this work was to develop and characterize the oil-in-water nanoemulsions based on two betaine-derived surfactants with high biodegradability, i.e., cocamidopropyl betaine and coco-betaine. In the first step, we investigated ternary phase diagrams of surfactant-oil-water systems containing different weight ratios of surfactant and oil, as the betaine-type surfactant entity (S), linoleic acid, or oleic acid as the oil phase (O), and the aqueous phase (W) using the titration-ultrasound approach. All the received nanoemulsion systems were then characterized upon droplets size (dynamic light scattering), surface charge (electrophoretic light scattering), and morphology (transmission electron as well as atomic force microscopy). Thermal and spinning tests revealed the most stable compositions, which were subjected to further kinetic stability analysis, including turbidimetric evaluation. Finally, the backscattering profiles revealed the most promising candidate with a size <200 nm for potential delivery of active agents in the future cosmetic, pharmaceutical, and biomedical applications.

Decoration of Squalenoyl-Gemcitabine Nanoparticles with Squalenyl-Hydroxybisphosphonate for the Treatment of Bone Tumors.

Therapeutic perspectives of bone tumors such as osteosarcoma remain restricted due to the inefficacy of current treatments. We propose here the construction of a novel anticancer squalene‐based nanomedicine with bone affinity and retention capacity. A squalenyl‐hydroxybisphosphonate molecule was synthetized by chemical conjugation of a 1‐hydroxyl‐1,1‐bisphosphonate moiety to the squalene chain. This amphiphilic compound was inserted onto squalenoyl‐gemcitabine nanoparticles using the nanoprecipitation method. The co‐assembly led to nanoconstructs of 75 nm, with different morphology and colloidal properties. The presence of squalenyl‐hydroxybisphosphonate enhanced the nanoparticles binding affinity for hydroxyapatite, a mineral present in the bone. Moreover, the in vitro anticancer activity was preserved when tested in commercial and patient‐treated derived pediatric osteosarcoma cells. Further in vivo studies will shed light on the potential of these nanomedicines for the treatment of bone sarcomas.

Adsorption and Aggregation Behavior of Mixtures of Quaternary-Ammonium-Salt-Type Amphiphilic Compounds with Fluorinated Counterions and Surfactants.

The surface adsorption and aggregation behavior of a mixture of quaternary-ammonium-salt-type amphiphilic monomeric compounds (C4 FSA, C8 FSA, and C4 NTf2) or gemini compounds (C10-2-C4 FSA) and various surfactants (nonionic hexaoxyethylene dodecyl ether (C12EO6), anionic sodium dodecyl sulfate (SDS), cationic dodecyltrimethylammonium bromide (C12TAB), and zwitterionic N-dodecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (C12Sb)) was investigated. Both types of compounds contained alkyl chains of nonidentical lengths that used bis(fluorosulfonyl)imide (FSA-) or bis(trifluoromethanesulfonyl)imide (NTf2-) as counterions. The mixtures were analyzed for surface tension, viscosity, electrical conductivity, and pyrene fluorescence, in addition to evaluation by cryogenic transmission electron microscopy, small-angle X-ray scattering, and dynamic light scattering. Our results showed that the surface tension depended on the surfactant structure. For the mixture of C8 FSA and SDS, as the SDS concentration increased, the surface tension first decreased and became constant at the critical micelle concentration (CMC). In this concentration range, C8 FSA and SDS were approximately equimolar (2.5 mmol dm-3), the mixture adsorbed efficiently at the air-water interface, and vesicles and linear-type micelles were formed in the solution owing to the decreased electrostatic repulsion between the hydrophilic groups. As the SDS concentration further increased, the surface tension increased and reached another constant value. The C8 FSA at the interface was replaced by SDS and the aggregates transformed into spherical micelles. The surface tension plot of the mixture of the amphiphilic compounds and C12Sb showed a minimum at the CMC. The lowest CMC and surface tension were observed for C10-2-C4 FSA, indicating that the gemini compounds offer excellent adsorption and orientation at the air-water interface. It was revealed that the quaternary-ammonium-salt-type amphiphilic compounds in this study acted as ionic liquids on their own and as surfactants in aqueous solution. Further, they could improve the surface activity of conventional ionic surfactants.