[Study of 2,6-di(propan-2-yl)phenol stability in biomaterial]. / Izuchenie ustoichivosti 2,6-di(propan-2-il)fenola v biologicheskom materiale.

The aim of this study is to research the stability of 2.6-di(propan-2-yl)phenol in biomaterial. GC-MS (column DB-5MS EVIDEX (25 m×0.2 mm); stationary liquid phase of 5%-phenyl-95% dimethylpolysiloxane), TLC (Sorbfil plates, mobile phase of hexane-diethyl ether (9:1) and spectrophotometry (solvent medium - 95% ethanol) were used as methods of analysis. 2.6-di(propan-2-yl)phenol was isolated from the biomatrix (liver tissue) by infusion with a mixture of ethyl acetate-acetone (7:3). The analyte was purified by combining extraction (water-ethyl acetate system) and semi-preparative chromatography on a column of silica gel L 40/100 µm, eluent - hexane-acetone (7:3). It was found that at -22 °C, 0 °C, 12 °C, 20 °C and 30 °C 2.6-di(propan-2-yl)phenol can be present in the liver tissue for 119, 98, 70, 56 and 42 days, respectively. The possibility of mathematical description of analyte decomposition dynamics in biomaterial (liver tissue) at the considered temperatures on the basis of hyperbola equation has been studied. The experimentally calculated coefficients in the hyperbola equation (km) for temperatures -22 °C, 0 °C, 12 °C, 20 °C and 30 °C are equal to 1823, 1130, 697, 510, and 255, respectively. The dependence km on the conserving temperature (tо) was educed. The equation for the description of dependence is offered: km=30.61∙(50-to)-402.39. It is shown that this equation can be the basis for prediction of 2.6-di(propan-2-yl)phenol stability in biomaterial (liver tissue) in the temperature range from -22 °C to 30 °C.

[Study of the stability of 2-methoxy-4-(2-propenyl) hydroxybenzene in biological material]. / Izuchenie ustoichivosti 2-metoksi-4-(2-propenil) gidroksibenzola v biologicheskom materiale.

The purpose of this work is to study the stability of 2-methoxy-4-(2-propenyl)hydroxybenzene [2-MO-4-(2-P)HOB] in biological material. For analysis, gas chromatography-mass spectrometry (GC-MS) was used: column DB-5MS EVIDEX (25 m × 0.2 mm) with a stationary phase of 5%-phenyl-95%-dimethylpolysiloxane; thin layer chromatography (TLC): Sorbfil plates, hexane-dioxane-propanol-2 mobile phase (40:5:1) and UV spectrophotometry (solvent - 95% ethanol). 2-MO-4-(2-P)HOB was isolated from the biomatrix (liver tissue) by infusion with a mixture of ethyl acetate-acetone (7:3). Purification of the analyte was carried out by combining extraction (water-ethyl acetate system) and semi-preparative column chromatography [sorbent - silica gel L 40/100 µm, eluent - hexane-dioxane (8.5:1.5)]. It was established that at -22 °C, 4 °C, 12 °C, 20 °C and 30 °C 2-MO-4-(2-P)HOB is stored in the liver tissue for 385, 357, 301, 245 and 217 days, respectively. We studied the possibility of mathematical description of the dynamics of analyte decomposition in a biomaterial (liver tissue) at the indicated temperatures using the hyperbolic equation. The coefficients in the hyperbola equation (kav), calculated according to the results of the experiment, for temperatures of -22 °C, 4 °C, 12 °C, 20 °C and 30 °C amounted to 6223, 3036, 2387, 1903 and 932, respectively., which is described by the equation: kav=101.19∙(50-to)-1272.78. It was established that on the basis of this equation it is possible to predict the nature of the stability of 2-MO-4-(2-P)HOB in the biomaterial (liver tissue) at temperatures in the range from -22 °C to 30 °C.

[Features of assay and decomposition dynamics of 2-methoxy-4-(1-propenyl)hydroxybenzene in biological material]. / Osobennosti opredeleniya i dinamiki razlozheniya 2-metoksi-4-(1-propenil)gidroksibenzola v biologicheskom materiale.

The objective was to study the features of assay and dynamics of decomposition of 2-methoxy-4-(1-propenyl)hydroxybenzene in biological material. Extraction, semi-preparation chromatography, TLC, HPLC, GC-MS and UV-spectrophotometry were used as test methods. 2-Methoxy-4-(1-propenyl)hydroxybenzene was extracted from the biological material by double infusion (45 min each) with ethyl acetate at a 2:1 mass ratio of isolating agent and biomatrix. Purification was performed by extraction and chromatography in a semi-preparative (190×10 mm) L 40/100 µm silica gel column using a hexane-dioxane (7:3) eluent. The analyte was determined by TLC methods (Sorbfil plates, hexane-acetone 9:1 as a mobile phase), HPLC [Discovery C18 HPLC Column (250×4.6 mm), acetonitrile-acetate buffer pH 5.5 (5:5) as a mobile phase], GC-MS [DB-5MS EVIDEX (25 m×0.2 mm) column with 5%-phenyl-95% dimethyl polysiloxane as a stationary phase], UV-spectrophotometry (95% ethanol as a solvent). The proposed assay method for 2-methoxy-4-(1-propenyl)hydroxybenzene in biomaterial (liver tissue) is validated for linearity, selectivity, accuracy and precision. The study results showed that the decomposition rate of the analyte increases as the store temperature increases. At 0-2 °C, 8-10 °C and 18-22 °C 2-methoxy-4-(1-propenyl)hydroxybenzene is stable for 480, 390 and 260 days respectively.

[Features of determination of 2-methoxyhydroxybenzene in the study of biological material]. / Osobennosti opredeleniya 2-metoksigidroksibenzola pri issledovanii biologicheskogo materiala.

The aim of the study was to develop a method for the determination of 2-methoxyhydroxybenzene in biological material. TLC, UV spectrophotometry, HPLC and GC-MS were used in the experiments. The use of a mixture of ethyl acetate-acetone (7:3 by volume) for the isolation of 2-methoxyhydroxybenzene from biological material is justified. Optimal isolation conditions are established. Purification of the substance was carried out by extraction and chromatography in sorbent column (KCC-3) 80/120 µm. For preliminary identification, TLC was used on Sorbfil PTSX-AF-A-UV plates. Confirmation of identification was carried out by the UV spectrum in ethanol by HPLC with the retention time in a 250×4.6 mm column «SunFire C18¼ (mobile phase acetonitrile-0.025 M potassium dihydrogen phosphate solution 6: 4). Confirmation identification and quantification was performed by GC-MS using a fixed phase capillary column of 5% phenyl-95% methyl polysiloxane after derivatization of the analyte with N-trimethylsilyl-N-methyl trifluoroacetamide (heating for 30 min at a temperature of 60 °C). Ions 45, 58, 73, 91, 107, 136, 151, 166, 181, 196 m/z are present in the mass spectrum of the derivative. The validation of the methodology for the determination of 2-methoxyhydroxybenzene in biomaterial based on the application of the GC-MS method was carried out. The compliance of the methodology with the criteria of linearity, selectivity, correctness, precision and stability is established. The detection limit and the limit of quantification are 8 and 15 µg per 100 g of biomaterial, respectively.

[Specific features of 2-methyl hydroxybenzene and 3-methyl hydroxybenzene distribution in the organism of warm-blooded animals].

The present work was designed to study the specific features of 2-methyl hydroxybezene and 3-methyl hydroxybenzene distribution after intragastric administration of these toxicants to warm-blooded animals (rats). They were detected in the unmetabolized form in the internal organs and blood of the animals. The levels of 2-methyl hydroxybezene were especially high in the stomach and blood whereas the maximum content of 3-methyl hydroxybenzene was found in brain, blood, small intestines of the poisoned rats.

[Study of eugenol distribution in the body of warm-blooded animals after lethal poisoning].

This study was designed to investigate the distribution of eugenol (2-methoxy-4-allylhydroxybenzene) in different tissues of homoiothermal animals (rats) after the intragastric administration of this toxic agents. It was shown that 2-methoxy-4-allylhydroxybenzene was present in large quantities in blood and splanchnic organs of the poisoned animals. The largest amounts of eugenol were found in the stomach and small intestine, their contents, spleen, and heart.

[Extraction of basic metabolites of monomethyloxybenzene isomers from aqueous solutions].

The results are presented of extraction of 1-methyl-3,4-dioxybenzene, 1-methyl-2,5-dioxybenzene and 4-oxybenzene acid from aqueous solutions with hydrophobic and hydrophilic organic soluvants. It is shown that the degree of extraction depends on the nature of the extragents and pH of the aqueous phase medium. Extraction multiplicity for obtaining necessary quantities of the compounds is calculated.

[Extraction of 2-methyl-hydroxybenzene and 3-methyl-hydroxybenzene from water solutions]. / Osobennosti ékstragirovaniia 2-metiloksibenzola i 3-metiloksibenzola iz vodnykh rastvorov.

The results related with extracting 2- and 3-methyloxibenzole from water solutions by 5 hydrophobic and 2 hydrophilic organic solvents are described in the paper. A variety of factors are shown to exert influence on an extraction degree: extraction agent (EA) nature, water-phase medium pH, EA saturation with water and adding of electrolytes to the water phase. A repetition factor needed to extract the preset quantities of studied compounds is estimated.

[Extraction of 1,2- and 1,4-dihydroxybenzene from water solutions]. / Ekstragirovanie 1,2- i 1,4-dioksibenzola iz vodnykh rastvorov.

The results of extraction of 1,2- and 1,4-dihydroxybenzene from water solutions by the hydrophobic and hydrophilic organic solvents are described. The influence of an extragent nature and of a water-phase pH medium on an extraction degree is demonstrated. The repetition factor needed to extract a preset quantity of examined compounds is calculated.

[Features of extracting phenol and 4-methylphenol from aqueous solutions]. / Osobennosti kstragirovaniia fenola i 4-metilfenola iz vodnykh rastvorov.

Phenol and 4-methylphenol were extracted from aqueous solutions by 5 organic solvents. The degree of extraction depended on such factors as type of extracting agent, pH of aqueous phase, and water saturation of extracting agent. The necessary number of extractions for obtaining the preset volumes of studied compounds is calculated.

[Distribution of 4-methylphenol in warm blooded animals]. / Raspredelenie 4-metilfenola v organizme teplokrovnykh zhivotnykh..

The distribution of 4-methylphenol in warm-blooded animals (rabbits) was studied after intragastric administration of the toxin. 4-methylphenol (free or bound) is present largely in the urine, liver and kidney tissues.