Amphiphilic Compounds Research Articles

Characterization, solubility and biological activity of amphihilic biopolymeric Schiff bases synthesized using chitosans

Chitosans are versatile biopolymers recognized for their wide range of biological activities. However, the low solubility in neutral and basic solutions restricts the applications. Thus amphiphilic biopolymeric Schiff bases from chitosans, salicylaldehyde and glycidol were successfully synthesized and characterized using 1H-NMR, UV/Vis, FTIR, TG/DTG-DTA and tested for their antimicrobial activities against plant pathogenic microorganisms and human breast cancer cells (MCF-7). Overall, functionalization of chitosans with salicylaldehyde and glycidol with different molecular weight (Mw¯) was performed to improve the biological actives of chitosans. Thus the biological activity of the new amphiphilic compounds prepared in this work were evaluated regarding microorganisms with agricultural relevance and tumor cells. The biopolymeric amphiphilic Schiff bases showed significant effects against Pseudomonas syringae (IC50 < 5 μg mL−1) compared to the natural chitosans with medium Mw¯ (CHM 223 kDa) and low Mw¯ (CHL 64 kDa), which had IC50 values of 42 and 37 μg mL−1, respectively. In addition, they improved antitumor activity against tumor cells compared to the natural chitosan.

Surfactin effectively inhibits Staphylococcus aureus adhesion and biofilm formation on surfaces.

Biosurfactants are amphiphilic compounds that composed of hydrophilic and hydrophobic moieties, which possess the ability of self-organizing between phases, reducing the interfacial tension, and forming aggregates such as micelles. This spontaneous process results in significant changes in surface properties that directly influence the adherence of microorganisms. In this study, the ability of surfactin, a biosurfactant produced by Bacillus subtilis in reducing adhesion and disrupting the presence of biofilm of Staphylococcus aureus (S. aureus) on several surfaces, was investigated. Significant biofilm removal was observed on glass, polystyrene, and stainless steel surfaces. Furthermore, we explored the probable mechanism about how surfactin affected S. aureus biofilm formation. Based on our findings, surfactin had a significant effect on the polysaccharides production and especially decreased the percentage of alkali-soluble polysaccharide in biofilms. It also down-regulated the expression of icaA and icaD significantly, which are necessary for the important constituents to take shape of staphylococcal biofilm. In addition, it was found that the lipopeptide affected the quorum sensing (QS) system in S. aureus through regulating the auto inducer 2 (AI-2) activity, which has been reported to be negative for biofilm formation in S. aureus. These above properties could be applied in developing surfactin as a potential pre-coating agent on material surfaces to prevent S. aureus biofilm formation.

Polymeric micelles of pluronic F127 reduce hemolytic potential of amphiphilic drugs

One of the main toxicities associated to intravenous administration of amphiphilic drugs is pronounced hemolytic activity. To overcome this limitation, we investigated the anti-hemolytic properties of polymeric micelles of Pluronics, triblock copolymers of poly(ethylene oxide) and poly(propylene oxide). We studied the encapsulation of the amphiphilic compound miltefosine (HePC) into polymeric micelles of Pluronics F108, F68, F127, L44, and L64. In vitro hemolysis indicated that, among the five copolymers studied, only F127 completely inhibited hemolytic effect of HePC at 50 μg/mL, this effect was also observed for other two amphiphilic molecules (cetyltrimethylammonium bromide and cethylpyridinium chloride). To better understand this interaction, we analyzed the HC50 (concentration causing 50% of hemolysis) for HePC free and loaded into F127 micelles. Copolymer concentration influenced the hemolytic profile of encapsulated HePC; for F127 the HC50 increased relative to free HePC (40 μg/mL) up to 184, 441, 736 and 964 μg/mL, for 1, 3, 6 and 9% F127, respectively. Interestingly, a linear relationship was found between HC50-HePC and F127 concentration. At 3% of F127, it is possible to load up to 300 μg/mL of HePC with no hemolytic effect. By achieving this level of hemolysis protection, a promising application is on the view, bringing the parenteral use of HePC and other amphiphilic drugs. Additionally, small-angle X-ray scattering (SAXS) was used to asses structural information on the interactions between HePC and F127 micelles.

Formation of complex organic molecules in astrophysical environments: Sugars and derivatives

AbstractCarbonaceous meteorites contain a large variety of complex organic molecules, including amino acids, nucleobases, sugar derivatives, amphiphiles, and other compounds of astrobiological interest. Photoprocessing of ices condensed on cold grains with ultraviolet (UV) photons was proposed as an efficient way to form such complex organics in astrophysical environments. This hypothesis was confirmed by laboratory experiments simulating photo-irradiation of ices containing H2O, CH3OH, CO, CO2, CH4, H2CO, NH3, HCN, etc., condensed on cold (~10–80 K) substrates. These experiments resulted in the formation of amino acids, nucleobases, sugar derivatives, amphiphilic compounds, and other organics comparable to those identified in carbonaceous meteorites. This work presents results for the formation of sugars, sugar alcohols, sugar acids, and their deoxy variants from the UV irradiation of ices containing H2O and CH3OH in relative proportions 2:1, and their comparison with meteoritic data. The formation mechanisms of these compounds and the astrobiological implications are also discussed.

Self‐Delivery Nanoparticles of Amphiphilic Acyclic Enediynes for Efficient Tumor Cell Suppression

Summary of main observation and conclusionFour acyclic maleimide‐based enediyne compounds with different hydrophilicity were synthesized through Sonogashira reaction to reveal a self‐delivery antitumor drug platform. As proved by ESR analysis, the enediyne compounds undergo Bergman‐like cyclization and generate diradical intermediates at physiological temperature, which are able to induce DNA‐cleavage through the abstraction of H atoms from the sugar‐phosphate backbones. When the critical aggregation concentration is reached in water, the amphiphilic enediyne compounds self‐assemble into nanoparticles and possess the self‐delivery ability to be facilely admitted by tumor cells, resulting in greatly improved cytotoxicity (IC50 down to 10 μmol·L–1) and much higher tumor cell apoptosis rate (up to 86.6%) in comparison with either the hydrophilic or the lipophilic enediyne compound. The enhanced endocytosis of the amphiphilic enediyne compounds was further confirmed through confocal laser scanning microscopy analysis. The unveiled relationship between the hydrophilicity of enediyne drugs and their therapeutic efficacy will provide a guideline for the design of new self‐delivery drugs employed in medicinal applications.

Cationic biaryl 1,2,3-triazolyl peptidomimetic amphiphiles targeting Clostridioides (Clostridium) difficile: Synthesis, antibacterial evaluation and an in vivo C. difficile infection model

Clostridioides (formerly Clostridium) difficile is a Gram-positive anaerobic bacterial pathogen that causes severe gastrointestinal infection in humans. The current chemotherapeutic options are vastly inadequate, expensive and limited; this results in an exorbitant medical and financial burden. New, inexpensive chemotherapeutic treatments for C. difficile infection with improved efficacy are urgently needed. A streamlined synthetic pathway was developed to allow access to 38 novel mono- and di-cationic biaryl 1,2,3-triazolyl peptidomimetics with increased synthetic efficiency, aqueous solubility and enhanced antibacterial efficacy. The monocationic arginine derivative 28 was identified as a potent, Gram-positive selective antibacterial with MIC values of 4 μg/mL against methicillin-resistant Staphylococcus aureus and 8 μg/mL against C. difficile. Furthermore, the dicationic bis-triazole analogue 50 was found to exhibit broad-spectrum activity with substantial Gram-negative efficacy against Acinetobacter baumannii (8 μg/mL), Pseudomonas aeruginosa (8 μg/mL) and Klebsiella pneumoniae (16 μg/mL); additionally, compound 50 displayed reduced haemolytic activity (<13%) in an in vitro haemolysis assay. Membrane-disruption assays were conducted on selected derivatives to confirm the membrane-active mechanism of action inherent to the synthesized amphiphilic compounds. A comparative solubility assay was developed and utilized to optimize the aqueous solubility of the compounds for in vivo studies. The biaryl peptidomimetics 28 and 67 were found to exhibit significant efficacy in an in vivo murine model of C. difficile infection by reducing the severity and slowing the onset of disease.

Pitfalls associated with lipophilic fluorophore staining of extracellular vesicles for uptake studies

ABSTRACTPost-staining of extracellular vesicles (EVs) with lipid-anchored fluorophores (LAFs) such as PKH67 is a widely used strategy for studying EVs but it is associated with several pitfalls. The pitfalls discussed in this commentary are related to LAF labelling of non-EV species due to (1) lipoprotein contamination in EV samples, (2) desorption of the LAF reporters from vesicles into proteins and lipoproteins in blood and serum, and (3) the capability of the amphiphilic LAF compounds to form EV-like particles. Awareness of these challenges and developing solutions to overcome these are important to ensure that we make relevant interpretations when using LAFs to track EVs.

Cationic biaryl 1,2,3-triazolyl peptidomimetic amphiphiles: synthesis, antibacterial evaluation and preliminary mechanism of action studies

Synthetic small molecular antimicrobial peptidomimetics represent a promising new class of potential antibiotics due to their membrane-disrupting ability and their decreased propensity for bacterial resistance. A library of 43 mono- and di-cationic biaryl 1,2,3-triazolyl peptidomimetics was designed and synthesized based upon previously established lead biarylpeptidomimetics and a known pharmacophore. A reliable, facile and modular synthetic pathway allowed for the efficient synthesis of multiple unique scaffolds which were subjected to divergent derivatization to furnish the amphiphilic compounds. In vitro testing revealed enhanced antibacterial efficacy against a range of pathogenic bacteria, including bacterial isolates with methicillin, vancomycin, daptomycin, or multi-drug resistance. Preliminary time-kill kinetics and membrane-disruption assays revealed a likely membrane-active mechanism for the tested peptidomimetics. An optimal balance between hydrophobicity and cationic charge was found to be essential for reduced cytotoxicity/haemolysis (i.e. membrane selectivity) and enhanced Gram-negative activity. The cationic biaryl amphiphile 81 was identified as a potent, broad-spectrum peptidomimetic with activity against Gram-positive (methicillin-resistant Staphylococcus aureus - MIC = 2 μg/mL) and Gram-negative (Escherichia coli - MIC = 4 μg/mL) pathogenic bacteria.

P-Glycoprotein Activity Is Non-Monotonically Modulated by Transmembrane Voltage

P-glycoprotein (Pgp) is a broadly polyspecific exporter of hydrophobic and amphiphilic compounds that plays an important role in the blood-brain barrier and in multidrug resistance in cancer. Several research groups have recently made significant strides toward elucidating the mechanism of Pgp's catalytic cycle, but the biophysical properties of the cellular microenvironment can have strong effects on the function of Pgp and other ATP-binding cassette (ABC) transporters in as-yet poorly defined ways. Here we report that Pgp, MRP1, and BCRP, three of the most clinically relevant multidrug resistance-linked ABC transporters, are strongly and non-monotonically regulated by the transmembrane electrical potential difference. We confirmed this result with several assays, which used fluorescence and electrophysiological methods to measure the efflux of transporter substrates from two human cell lines and giant unilamellar vesicles and controlled the voltage using electrolyte gradients or the patch clamp technique. At hyperpolarized (highly inside-negative) potentials, each transporter displayed a pronounced reduction in efflux activity compared to the activity at the resting potential; Pgp and MRP1 also showed reduced activity at inside-positive potentials. The transport data is well-described by a model in which the transmembrane potential biases the conformational distribution of the proteins in a manner similar to the mechanism of action of voltage-gated ion channels. In this model, which is compatible with the “alternating access” framing of Pgp function, each catalytic cycle contains two transitions with an opposite dependence on the transmembrane voltage due to the movement of an equivalent of 3-4 elementary charges back and forth across the membrane. This finding, which points to an additional axis for modulating transporter activity, underscores the importance of electric field effects on the function of all membrane proteins, particularly those that undergo large conformational changes in the transmembrane region.

Sphingomyelin Plays a Critical Role in Membrane-Related Effects Induced by the Steroid Saponin Ginsenoside Rh2

Cholesterol (Chol) and sphingomyelin (SM) are known to cluster into transient nanometric domains, forming a liquid ordered (Lo) phase. These domains serve as a platform that contributes to cellular signaling including cell survival or proliferation with potential implications in cancer development. Saponins, amphiphilic compounds widely found in plants, attract more and more attention based on their biological activities including anticancer properties. Although the activity for most saponins (e.g. digitonin, α-hederin) is usually attributed to their interactions with membrane Chol, our recent publication showed that Chol, contrary to SM, delays the cytotoxicity of the saponin ginsenoside Rh2 in human cancer cell lines (A549, THP-1, and U937)[1], renewing the idea that saponin activity is only ascribed to an interaction with Chol. In this study, we elucidated the respective importance of Chol and SM in the membrane-related effects of Rh2 using a large panel of biophysical approaches while carefully modulating their lipid compositions, i.e. the presence or absence of Chol or SM. Using lipid monolayers, we observed that Rh2 preferentially interacted with eSM:ePC, then eSM:ePC:Chol followed by ePC:Chol. Using Large Unilamellar Vesicles (LUVs), we found that Rh2 increased the vesicle size, decreased membrane fluidity and induced membrane permeability with the same ranking, i.e eSM:ePC>eSM:ePC:Chol>ePC:Chol. Using Giant Unilamellar Vesicles (GUVs), Rh2 generated positive curvature in SM-containing membrane and small buds followed by intra-luminal vesicles in the absence of SM. Altogether, our results indicate that SM promotes and accelerates membrane-related effects induced by Rh2. To the best of our knowledge, this study is the first to reveal the critical role of SM in membrane-related effects induced by a saponin reconsidering the theory that Chol is the only responsible for the activity of saponins. [1] Toxicol Appl Pharmacol 352, 59-67(2018).

β-Cyclodextrin-Functionalized Cellulose Nanocrystals and Their Interactions with Surfactants.

β-cyclodextrin (β-CD) forms a host–guest inclusion complex with many organic and amphiphilic compounds found in pharmaceutical, textile, cosmetic, food, and personal care systems. Therefore, grafting of β-CD onto a cellulose nanocrystal (CNC) offers a possible strategy to use functionalized CNC to complex with surface-active molecules. We have successfully grafted β-CD onto CNCs in a stepwise manner using cyanuric chloride as the linker. The structure of β-CD-grafted CNC (CNC-CD) was characterized by UV–vis and Fourier-transform infrared spectroscopy, and the grafting ratio of β-CD was determined by the phenolphthalein inclusion protocol. Ionic surfactants induced the aggregation of CNC-CDs by forming inclusion complexes with β-CDs on the surface of CNC. The interactions of amphiphilic compounds with CNC-CD were examined by surface tensiometry, conductometric and potentiometric titration, and isothermal titration calorimetry. Mechanisms describing the complex formation between surfactants and CNC-CD were proposed, where an improved understanding of CD interactions with surfactants and lipids would enable better strategies for drug encapsulation and delivery with CDs.

Different behaviors of self-assembled nanostructure with three-types of azopyridine hydrochloride salts

Based on the present research in the self-assembly of azopyridine derivatives, we designed a series of representative derivatives: lipophilic compounds with rigid chains(AzoPyChol), lipophilic compounds with flexible chains(AzoPyC16), amphiphilic compounds(AzoPyAp). The derivatives interacted with inorganic acid (concentrated HCl) to form hydrochloride salts (AzoPyChol-HCl, AzoPyC16-HCl and AzoPyAp-HCl). According to the results of SEM images and UV–vis absorption spectra, AzoPyAp-HCl showed better morphological stability in different solvents. The changes in self-assembly behavior of hydrochloride salts were proved via XRD and fluorescence analysis. Liquid crystal of the azopyridine derivatives were illustrated by differential scanning calorimetry(DSC) and polarizing microscope(POM).

A versatile supercritical assisted process for the one-shot production of liposomes

Liposomes are spherical vesicles made of a double layer of phospholipids and an inner water volume; these biocompatible drug carriers are used for the vehiculation of hydrophilic, amphiphilic or lipophilic compounds. Conventional methods for the production of liposomes are characterized by several drawbacks such as low encapsulation efficiencies, difficult control of particle size distribution, high solvent residue and necessity of expensive post-processing steps. To overcome these limitations, SuperLip (Supercritical assisted Liposome formation) has been developed, consisting in the inversion of the traditional liposome production steps: water droplets are obtained; then, lipidic layer is formed around them.Nanometric and sub-micrometric vesicles were obtained entrapping proteins, antibodies, antibiotics, essential oils, agricultural additives, antioxidants, dyes and hollow gold nanoparticles. The continuity of the process guaranteed reproducible production of liposome suspensions, whose bulk stability was confirmed for at least 6 months. After process parameters optimization, encapsulation efficiencies up to 99% were obtained.

Flexible free-standing films morphology characterization: PVA/silica polymer network dispersed cholesteric liquid crystals films by sol-gel method

ABSTRACTA novel flexible free-standing films of polyvinyl alcohol (PVA)/silica polymer network dispersed cholesteric liquid crystals (CLC) have been prepared by the sol-gel process. In the hydrolysis of silicon alkoxides tetraethoxysilane (TEOS) processes, the silica having -OH with the -OH groups on PVA formed polymer networks with Si-O-C bonds by dehydration. The cholesteric liquid crystals were incorporated into the networks. The free-standing films were obtained by the spin-coating method. In order to improve the compatibility and microstructure of the cholesteric liquid crystals with PVA/silica polymer networks, the amphiphilic compound of hexadecyl trimethyl ammonium bromide (HDTMA) was introduced into the forming film solutions. Effects of the different ratios of raw materials on the structure of films were investigated. The microscopic morphology of free-standing films and the uniform dispersion of CLCs in the films have been characterized by polarizing optical microscopy (POM), the field emission scanning electron microscope (FESEM), Fourier transform infrared (FT-IR) spectrometer and atomic force microscope (AFM). The free-standing films exhibiting excellent CLC droplets dispersion, mechanical stability, and good flexibility could be useful for flexible displays, switchable optical elements and smart windows.

Oleic Acid Based Cyclodextrins for the Development of New Hydrosoluble Amphiphilic Compounds

A new family of amphiphilic cyclodextrins produced from oleic acid derivatives and maleic anhydride is described. These amphiphilic cyclodextrins are synthesized in two steps. The first step is the alkenylation of maleic anhydride by oleic acid derivatives to produce the oleic succinic anhydrides. The second step is the grafting of the oleic succinic anhydrides on various cyclodextrins. A self‐inclusion of the alkyl chain or an inclusion of one alkyl chain in the cavity of another CD is showed by NMR experiments. The twelve amphiphilic cyclodextrins described possess high solubility in water (50–500 g/L at 20 °C) and low critical aggregation concentration (16–360 mg/L).

Influence of the hydrophobic domain on the self-assembly and hydrogen bonding of hydroxy-amphiphiles.

The amphiphiles 1-octadecanol (octadecyl (stearyl) alcohol, ODA) and 1,2-dioleoylglycerol (DOG) were studied by IR spectroscopy and X-ray diffraction combined with multiscale theoretical modeling. The computations allowed us to rationalize the experimental findings and deduce the supramolecular structure of the formed assemblies while providing a fairly detailed insight into their hydrogen-bonding patterns. IR spectra revealed that the amphiphilic assemblies dramatically differ in structural order and hydrogen-bond strength, both being high in ODA and low in DOG. On the other hand, both compounds demonstrated common features, namely a splitting of the IR bands arising from O-H stretching vibrations (νOH) as well as complete hydrophobicity. However, the observed phenomena have different origins in the two amphiphiles. While the νOH split in ODA occurs due to a vibrational coupling along the string of inter-layer O-HO hydrogen bonds, in DOG it arises from different types of hydrogen bonds (intra- and intermolecular). The hydrophobicity of ODA stems from the very tight O-HO hydrogen bonding network connecting the opposite monolayers in a densely packed tilted crystalline phase (Lc'), whereas in DOG it occurs because the polar sites are locked inside reverted micellar-like assemblies. ODA and DOG illustrate that, in the assemblies of amphiphilic hydroxyl compounds, hydrogen bonds can be formed in a wide structural latitude, which is primarily governed by the chemical nature of apolar chains. Such a wide structural variability of OH-involving hydrogen bonds can be essential for the biological functioning of relevant molecules, such as glycolipids, acylglycerols, and, potentially, glycoproteins and carbohydrates.

Blue-emitting bolaamphiphilic zwitterionic iridium(iii) complex.

Aggregation induced emission is a very interesting phenomenon that recently has attracted a lot of interest. Most of the examples deal with organic molecules or flat metal complexes. Here we demonstrate that, by design, even iridium compounds can display this process without shifting the emission energy. In order to enhance the aggregation properties we have focussed on amphiphilic complexes. We report the synthesis and photophysical characterisation of a blue-emitting bolaamphiphilic zwitterionic Ir(iii) complex and an analogous cationic amphiphilic compound, used as a reference. The bolaamphiphile exhibited blue (λmax = 450 nm) emission in dilute, deaerated solution with a photoluminescence quantum yield (PLQY) of 22%, similar to the related cationic amphiphilic complex. The bolaamphiphile displayed significant emission enhancement in the solid state, with an emission quantum yield that reach 52%. Interestingly, the emission of the cationic analogue suffers from aggregation quenching in the solid state, (PLQY = 3%) as is common for these type of complexes. A correlation between the photophysical data and the arrangement in the solid state is discussed.

Impact of amphiphilic compounds on post-hypertonic shock of human erythrocytes

When the cryopreserved erythrocytes are thawed, with the ice melting the extracellular hypertonic medium changes to isotonic one, resulting in post-hypertonic cell lysis development. Under experimental conditions, the post-hypertonic shock of erythrocytes simulates the influence of cryodamage factors, acting at the erythrocyte thawing stage, as well as when the cells, cryopreserved under protection of penetrating cryoprotectant are transferred into bloodstream. Post-hypertonic shock of erythrocytes was carried out by transferring the cells from a hypertonic solution contained 1.65 mol/l NaCl (dehydration medium) into an isotonic one with 0.15 mol/l NaCl (rehydration medium) at 0ºС. The effect of specimens of various classes of amphiphilic compounds (anionic sodium decyl sulfate, non-ionic decyl-β,D-glucopyranoside, and cationic chlorpromazine) on the human erythrocyte sensitivity to post-hypertonic shock, was studied. Amphiphilic substances were supplemented into rehydration medium prior to cell introduction into it. It was shown that under post-hypertonic shock of erythrocytes, all the studied amphiphilic substances, when used in efficient concentrations, manifested a high anti-hemolytic activity (at the level of 70%). A comparative study of the efficiency of amphiphilic substances under post-hypertonic shock of erythrocytes showed differences in size of the plateau (the concentration range of amphiphilic compound, within the limits of which the minimum level of erythrocyte hemolysis was observed). Thus, it was found that for non-ionic decyl-β,D-glucopyranoside the plateau was 3 times more than for anionic sodium decyl sulfate and cationic chlorpromazine. The minimum efficient concentration for sodium decyl sulfate and the maximum one for decyl-β,D-glucopyranoside under post-hypertonic shock of erythrocytes were revealed. It is assumed that the revealed protective effect of amphiphilic compounds under post-hypertonic shock of erythrocytes is associated with their capability to integrate into membrane. This entails an increase in the surface area of the membrane and, therefore, the critical hemolytic volume of cell, which allows it to swell to a larger volume.

Rhamno Lipids Biosurfactants from Pseudomonas aeruginosa - A Review

Studies addressing for ecological compatible products have been increased along time, especially, on biosurfactant field. Biosurfactants are extracellular amphiphilic compound that are mainly produced by microorganisms and are classified into five main groups, including the glycolipids one. Rhamnolipids are included in the latter and are anionic biosurfactants produced predominantly by Pseudomonas aeruginosa being classified as mono- and di-rhamnolipids. In addition, their production may occur from different carbon sources, which may be obtained from renewable and low-cost residue. Therefore, it is possible to reduce the rhamnolipids production cost, since this has been the main bottleneck for replacing the chemical surfactants. In addition, to meeting a bona fide industrial application some limitations such as low productivity as well as recovery and/or purification that represent from 60 to 80% of total production cost should be improved. Therefore, this review covers different ways for producing rhamnolipids covering their application in many fields such as pharmaceutical, agricultural, petrochemical and so on; demonstrating the versatility of these biological compounds.

ВПЛИВ ФЕНІЛГІДРАЗИНУ НА ГІПЕРТОНІЧНИЙ СТРЕС ЕРИТРОЦИТІВ ССАВЦІВ І АНТИГЕМОЛІТИЧНУ АКТИВНІСТЬ АМФІФІЛЬНИХ СПОЛУК

In the research work the initial level of erythrocyte damage of the investigated mammals has been shown to be significantly differed under hypertonic conditions. The level of human erythrocyte lysis in 4.0 mol/l NaCl at 37 °C made 90 %, for bovine cells it was 80 % and 60 % for equine ones. During the medium temperature decrease down to 0 °C the resistance of human, bovine and equine erythrocytes did not rise significantly. It has been demonstrated that sensitivity of mammalian erythrocytes to hypertonic stress at 37 °C after treatment with phenylhydrazine depended on the species of cells. Herewith the sensitivity of modified bovine and human erythrocytes was reduced and the equine ones increased. Sensitivity of rabbit erythrocytes after modification did not change statistically and significantly. Under hypertonic stress at temperature of 0 °C the rise in the damage rate of modified erythrocytes of all the investigated mammal species was observed. Trifluoperazine and dodecyl-b,D-maltoside has been established to manifest a high protective effect under hypertonic stress of erythrocytes for all the studied mammal species, excluding the rabbit erythrocytes. Trifluoperazine has a somewhat higher anithemolytic activity (about 80–90 %) if compared with dodecyl-b,D-maltoside (70 %). When decreasing in experiment the temperature down to 0 °C the antihemolytic activity of trifluoperazine and dodecyl-b,D-maltoside was strongly decreased. It has been shown that under hypertonic stress antihemolytic activity of amphiphilic compounds after modification of mammalian erythrocytes with phenylhydrazine was strongly decreased.