The derivatives of fatty acids are considered as promising bases for the development of medicinal and cosmetic agents. In this regard, it is necessary to study their potential toxicity, including chronic. In repeated toxicity experiments on mice of C57BL6 line, the administration of N-palmitoyl-5-aminolevulinic acid (within liposomes) for 62 days was less toxic than N-palmitoylglycine injected in the same regimen, which resulted in lower mortality of animals. The toxic effects of high doses, both PalGly and Pal-5-ALA, are characterized by a gender dependence: males were more sensitive to PalGly, whereas females - to Pal-5-Ala. Chronic administration of liposomes of phosphatidylcholine (without N-acylamino acids) caused the death of several mice, suggesting that the toxic effects of PalGly and Pal-5-ALA in liposomal form are at least partly due to the influence of the liposomes themselves.

The antinociceptive effect of palmitoylethanolamide (PEA), stearoyl- ethanolamide (SEA) and sodium diclofenac in experimental peripheral neuropathy in rats was studied. Intraperitoneal administration of PEA one hour prior to stimulation on the 7th and 14th day significantly weakened CCI-induced mechanical hyperalgesia by increasing PNR by 23.1 and 31.8 %, respectively. SEA under similar conditions increased PNR by 27.9 and 30.3 %, while diclofenac – by 29.0 and 26.2 %. New data were obtained and pointed that stearoylethanolamide effectively weakens mechanical hyperalgesia caused by neuropathy. The antinociceptive effects of these fatty acid derivatives in the modeling of neurogenic pain syndrome are comparable to those of sodium diclofenac. It seems advisable to consider PEA and SEA as a basis for drugs, whose addition to treatment regimens of neuropathic pain will increase its effectiveness.

Herein, the environmentally friendly synthesis of the earlier unknown phospholipid analog of kinetin riboside was carried out using phospholipase D of Streptomyces netropsis . Kinetin riboside and soybean lecithin served as substrates. A maximum degree of nucleoside conversion to 5′-phosphatidyl derivative of kinetin riboside at 37°С to 6 h exceeds 95%. The structure of target product was confirmed by UV and 1 Н NMR spectroscopy.

ГНУ «Институт физиологии НАН Беларуси» 1 , ГНУ «Институт биоорганической химии НАН Беларуси» 2 , г. Минск, Республика БеларусьЦель.Изучить ранозаживляющие свойства N-пальмитоилэтаноламина и N-стеароилэтаноламина в липосомальной форме, сравнить их действие с лекарственным средством с доказанной эффективностью.Материал и методы.Ранозаживляющее влияние N-пальмитоилэтаноламина и N-стеароилэтаноламина изучено на 214 белых рандомбредных крысах-самцах с тремя типами кожных ран: линейные, лоскутные и ожоговые.Для исследования каждого типа ран животные были разделены на группы: контрольная (раны не обрабатывались), отрицательный контроль (или растворитель), положительный контроль (мазь Метилурацил), пальмитоилэтаноламин и стеароилэтаноламин.Ежедневно проводили мониторинг общего состояния животных, фотосъемку ран

Aim. The object of this study was to implement computer-aided design of the water-soluble analog of glycolipid β-galactosylceramide (β-GalCer), which presents a potential HIV-1 entry inhibitor, by the analysis of intermolecular interactions of β-GalCer with the central region of the virus envelope gp120 V3 loop followed by synthesis of this glycolipid derivative and testing for antiviral activity. Methods. To reach the object of view, computer modeling procedures, such as quantum chemical calculations, molecular docking, molecular dynamics and free energy simulations, were involved in the studies in conjunction with chemical synthesis and anti-HIV-1 assay methods. Results. As a result, the high probability of exhibiting of antiviral activity was predicted for the designed β-GalCer analog. The data of molecular modeling were confirmed by those of primary medical trials of the synthesized compound. Conclusions. In the light of the findings obtained, the designed analog of β-GalCer may be considered as the basic structure for simulation of its more potent structural forms and for posterior selection of drug candidates most promising for synthesis and anti-HIV-1 assays.

The hemolytic activity of hexadecylphosphocholine (HePC) included in liposomes of phosphatidylcholine (PC), phosphatidylethanol (PET), and their mixture in various ratios has been studied. Spectroscopic data suggest that supramolecular particles containing less than 15% HePC occur as liposomes. Hemolysis at the same HePC concentration is less pronounced for liposomes (10% HePC) than for micelles (30% HePC). The inclusion of anionic phosphatidylethanol into the liposomal composition does not affect significantly the degree of hemolysis.

The hemolytic activity of hexadecylphosphocholine (HePC) included in liposomes of phosphatidylcholine (PC), phosphatidylethanol (PET) and their mixture in various ratios has been studied. The data of spectroscopic study suggest that supramolecular particles containing with HePC content below 15% occur in the state of liposomes. Hemolysis at the same concentration of HePC is less pronounced for liposomes (10% HePC) than for micelles (30% HePC). The inclusion of anionic phosphatidylethanol into liposomal composition does not very significantly affect the degree of hemolysis.

The experimental data on the formation of final products in the radiolysis of 2-aminoglycerol and lysosphingomyelin (sphingosine phosphocholine) and in the photolysis of N-(2-hydroxypropyl)hexanamide and sphingomyelin suggest the occurrence of the radiation-induced degradation of the above substances with C-C bond cleavage. It was hypothesized that this process occurs by the formation and subsequent degradation of the N-centered radicals of the substrates.

The ability of phospholipids with different structures of the polar head (phosphatidylpropandiol, phosphatidylglycerol, phosphatidylinositol, and cardiolipin) to sustain radiation-induced fragmentation was studied. It was shown by thin-layer chromatography and MALDI-TOF mass spectroscopy that all test lipids entering the composition of model membranes subjected to γ-irradiation suffered fragmentation yielding phosphatidic acid. The radiation-chemical yield of phosphatidic acid increased in this phospholipid series on passing from phosphatidylpropanediol to cardiolipin.

Для изучения биологических свойств ациламинокислот синтезированы N-арахидоноильные (АА) производные аминокислот: Gly, Phe, Pro, Val, у-аминомасляной кислоты (GABA), диоксифенилала-нина, Туг, Тгр и Ala, а также пептидов MEHFPGP и PGP. В масс-спектрах ионизации при атмосферном давлении распылением в электрическом поле все соединения дают протежированный молекулярный ион максимальной интенсивности, предел детектирования составлял 10 фмоль вещества на образец. Из всех изученных ациламинокислот наибольшую ингибиторную активность по отношению к гидролазе амидов жирных кислот из мозга крысы показал AA-Gly (IC5o 6.5 мкМ). Слабое, но регистрируемое ингибирование проявляли AA-Phe, АА-Туг и AA-GABA (1С5о 55, 60 и 50 мкМ соответственно). Сами ацилированные аминокислоты, за исключением AA-Gly, были устойчивы к гидролизу этим ферментом. Все арахидоноиламинокислоты в той или иной степени ингибировали фос-фолипазу D из капусты, наиболее активными оказались AA-GABA и AA-Phe (IC5o 20 и 27 мкМ соответственно). Опыты по выяснению возможности биосинтеза АА-Туг в гомогенатах печени и нервных тканях крысы не показали образования этой ациламинокислоты in vitro, однако были обнаружены продукты ее метаболизма: АА-дофамин и АА-(З-О-метилдофамин); наибольшее количество первого метаболита наблюдали в гомогенате печени, а второго - в гомогенате головного мозга. Ациламинокислоты не оказывали цитотоксического действия на клетки глиомы С6. Показано, что N-ацилирование гептапептида MEHFPGP (семакс) арахидоновой кислотой приводит к повышению его гидролитической стабильности и увеличению сродства к местам специфического связывания на мембранах мозжечка крысы.

Doxorubicin has been encapsulated into “solid” liposomes composed of a mixture of distearoyl analogs of phosphatidylcholine and phosphatidylethanol (in a 3: 2 molar ratio). The liposomes are sterically stabilized by incorporating a conjugate of dipalmitoylphosphatidylethanolamine with poly(ethylene glycol)-2000 in an amount of 5 wt % with respect to the total lipid content. The data of differential scanning microcalorimetry method show that the lipid bilayer of the doxorubicin-containing liposomes occurs in a gel-like (“solid”) state up to a temperature of 47°C. Estimated in terms of inhibition of the growth of solid and ascitic Ehrlich’s carcinoma in mice, the antitumor effect of such liposomes is equal to that of ordinary doxorubicin, whereas sterically non-stabilized “ solid” liposomes are 1.5 times less active.

The toxicity of sterically stabilized doxorubicin-containing "solid" liposomes comprising a mixture of distearoyl analogs of phospatidylcholine and phosphatidylethanol (in a 3 : 2 molar ratio) was evaluated. Upon injection of the ordinary and liposomal doxorubicin in a total dose of 12 mg/kg, the early loss of mice with implanted ascitic Ehrlich's carcinoma was 100 and 50%, respectively, and the average lifetime of the animals treated with liposomal doxorubicin was 1.6 times longer. In comparison to the ordinary doxorubicin, injections of the liposomal preparation resulted in a lower drop of the body weight (10%) and a smaller decrease in leukocyte number (12%). The results of fluorimetric measurements showed that the accumulation of antibiotic in the cardiac muscle 15 - 180 min after injection of liposomal doxorubicin was 30 - 57% lower than that upon the injection of the ordinary preparation.

The effect of the structure of the phospholipid substrate on the yield of phosphatidyl-5′-thymidine by transphosphatidylation catalyzed by phospholipase D from Streptomyces netropsis was studied. The reaction and product yield depended on the structures of the polar and nonpolar parts, the hydrophobic-hydrophilic balance, and the degree of unsaturation of the fatty-acids in the phospholipid substrate.

The effect of anionic phosphatidylethanol on the incorporation of doxorubicin into liquid-crystalline liposomes consisting of soybean phosphatidylcholine was studied. Over 90% of doxorubicin are encapsulated in liposomes in the case of a 3 : 2 phosphatidylcholine - phosphatidylethanol molar ratio, with a doxorubicin concentration reaching 130 mg/(mg of total phospholipids). The Stokes radius of the doxorubicin-containing liposomes was found to be about 160 Е. In terms of the ability to inhibit solid Ehrlich carcinoma in mice, the obtained liposome formulations of doxorubicin were much less effective in comparison to the usual antibiotic.

N-Arachidonoyl (AA) derivatives of amino acids (glycine, phenylalanine, proline, valine, γ-aminobutyric acid (GABA), dihydroxyphenylalanine, tyrosine, tryptophan, and alanine) and peptides (Semax, MEHFPGP, and PGP) were synthesized in order to study the biological properties of acylamino acids. The mass spectra of all the compounds at atmospheric pressure electrospray ionization display the most intense peaks of protonated molecular ions; the detection limits for these compounds are 10 fmol per sample. AA-Gly showed the highest inhibitory activity toward fatty acid amide hydrolase from rat brain (IC50 6.5 μM) among all the acylamino acids studied. AA-Phe, AA-Tyr, and AA-GABA exhibited a weak but detectable inhibitory effect (IC50 55, 60, and 50 μM, respectively). The acylated amino acids themselves, except for AA-Glu, were stable to the hydrolysis by this enzyme. All the arachidonoylamino acids inhibited cabbage phospholipase D to various degrees; AA-GABA and AA-Phe proved to be the most active (IC50 20 and 27 μM, respectively). Attempts to detect the biosynthesis of AA-Tyr in homogenates of rat liver and nerve tissue in vitro were unsuccessful; however, AA-dopamine and AA-Phe, the products of its metabolism, were found. The highest contents of these metabolites were detected in liver homogenate and in the brain homogenate, respectively. Acylamino acids exert no cytotoxic effect toward the glioma C6 cells. It was shown that N-acylation of Semax with arachidonic acid results in enhancement of its hydrolytic stability and increases its affinity for the sites of specific binding in rat cerebellum membranes.

The toxicity of sterically stabilized doxorubicin-containing “solid” liposomes comprising a mixture of distearoyl analogs of phospatidylcholine and phosphatidylethanol (in a 3: 2 molar ratio) was evaluated. Upon infusion of the ordinary and liposomal doxorubicin in a total dose of 12 mg/kg, the early loss of mice with implanted ascitic Ehrlich’s carcinoma was 100 and 50%, respectively, and the average lifetime of the animals treated with liposomal doxorubicin was 1.6 times longer. In comparison to the ordinary doxorubicin, administration of the liposomal preparation resulted in a lower drop of the body weight (10%) and a smaller decrease in leukocyte number (12%). The results of fluorimetric measurements showed that the accumulation of antibiotic in the cardiac muscle 15–180 min after infusion of the liposomal doxorubicin was 30–57% lower than that upon infusion of the ordinary preparation.

Doxorubicin has been encapsulated into liposomes composed of a mixture of distearoyl analogs of phosphatidylcholine and phosphatidylethanol (in a 3:2 molar ratio). The liposomes are sterically stabilized by incorporating a conjugate of dipalmitoylphosphatidylethanolamine with poly(ethylene glycol) 2000 (5 wt % with respect to the total lipid content). The data of differential scanning microcalorimetry method show that lipid bilayer of the doxorubicin-containing liposomes occurs in a gel-like (solid) state up to a temperature of 47 °С. Estimated in terms of inhibiting the growth of solid and ascitic Ehrlich's carcinoma in mice, the antitumor effect of such liposomes is equal to that of usual doxorubicin, whereas sterically non-stabilized liposomes are 1.5 times less active.

A method has been developed for preparing the unique phospholipid phosphatidylethanol, which is a marker of human and animal alcohol intoxication and acts as an effective component of liposomal forms of medicinal compounds. The method consists of preparation of the diethyl-ester of phosphatidic acid with subsequent removal of one ethyl by CsF in t-butanol.