Home – Home – Jornals – Chemistry for Sustainable Development 2023 number 6

1-(Pentafluorophenyl)propan-1-one reacts with zinc in the presence of catalytic amounts of SnCl₂ under heating in dimethyl formamide to give (2,3,5,6-tetrafluoro-4-propionylphenyl)zinc chloride and bis(2,3,5,6-tetrafluoro-4-propionylphenyl)zinc. 1,1'-(2,3,5,6-Tetrafluoro-1,4-phenylene)dipropan-1-one was synthesized from these organozinc compounds and propionyl chloride in the presence of CuI. The reaction of organozinc compounds obtained from 3-bromo-1,2,4,5-tetrafluorobenzene leads to the formation of 1-(2,3,5,6-tetrafluorophenyl)propan-1-one

The interaction of alkyl(4-X-2,3,5,6-tetrafluorophenyl)sulphanes (X = H, CF₃) containing difluoromethyl and benzyl groups as alkyl components with hydrogen peroxide in acetic or trifluoroacetic acid gave the corresponding sulphonyl derivatives. The effect of the acid used on the reaction result was established in the case of (difluoromethyl)[4-(trifluoromethyl)-2,3,5,6-tetrafluorophenyl]sulphane. The synthesis of 1-alkylsulphonyl-2,3,5,6-tetrafluorobenzenes scaling possibility to tens of grams was demonstrated. Product yields were 84-97%.

The synthesis of urea and thiourea containing adamantane and campholene fragments was performed starting from adamant-1-yl isocyanate, adamant-1-yl isothiocyanate and campholenyl amine. The synthesised compounds were modified to their oxalyl derivatives, which may be of interest for biological activity screening.

The paper presents the results of applying the methodology of chemical fingerprinting to survey the territories of industrial and natural objects, environmental accidents and objects of accumulated environmental damage in various regions of Siberia, including the Arctic zone of Russia. The data obtained by GC/MS using the capabilities of targeted and survey ecological analysis are presented. Polycyclic aromatic hydrocarbons, polychlorinated biphenyls, various classes of hydrocarbons, including relict oil biomarkers, chloro- and methylphenols, Cl-, N-, S-, O-organic compounds of various classes were considered as pollutants. The most important tools of chemical fingerprinting are considered, and it is shown that the use of a set of data on marker compounds of various types, diagnostic ratios of characteristic compounds, multi-vector chromatographic profiling of characteristic compounds ("fingerprints") makes it possible to establish the origin of pollution sources with a high degree of probability.

Drew-Dickerson Dodecamer (DDD) is one of the well-known DNA duplexes. It has been sufficiently well studied by various structure determination methods and appears to be a standard for developing new experimental techniques and molecular mechanical force fields. For this reason, the information about the dynamics of DDD on different time scales is important for constructing more accurate structural-dynamic models and carrying out molecular dynamics calculations of long-term time trajectories that allow simulation of real processes. In this work, the information on the dynamics of DDD base pairs on the milli- and microsecond time scale, currently missing from the literature, was obtained by means of imino protons’ nuclear spin relaxation ( R_1ρ) dispersion. It is shown for all the base-pairs, except for terminal and pre-terminal ones, that any dynamic processes in the range of R_1ρ method are not observed up to 300 K, but proceed on a faster time scale. For the pre-terminal GC pair, a pronounced dependence of the relaxation R_1ρ on the applied spin-lock field strength is observed, which allowed us to extract the information about the pair closing dynamics using a fast exchange model with highly skewed state populations. These data supplement the information obtained previously on the dynamics of DDD complementary base pairs by exchange-based water magnetization transfer experiments and provide a more complete view of the processes observed in DDD in relation to base pair opening-closing.

2-Methyl-9H-selenoxanthen-9-one (selenoxanthone) 1 was obtained by the reaction of bis-(2-carboxyphenyl)diselenide with toluene in concentrated sulphuric acid. It is demonstrated by means of cyclic voltammetry, EPR spectroscopy and quantum chemical DFT calculations that the electrochemical reduction (ECR) of selenoxanthone 1 in acetonitrile is a one-electron reversible process with the formation of a long-lived radical anion having a similar type of the highest occupied molecular orbital (HOMO) to the radical anions of the thioxanthone series. The ECR potential of selenoxanthone 1 is found to be less negative than the corresponding ECR potential of its related 2-methyl-9H-thioxanthen-9-one, which indicates an increase in the adiabatic electron affinity of selenoxanthone 1 compared to its sulphur-containing analogue. This fact confirms the general nature of the phenomenon of an increase in the adiabatic electron affinity of heterocyclic compounds when a heteroatom is replaced by a heavier one within group VIa of the periodic system of elements.

In the recent years, triarylmethyl radicals are widely used as spin probes and tags, so the study of their properties is of great interest. In the present work, the magnetic resonance properties of triarylmethyl radicals (FT (Finland trityl) and OX063) labeled with ¹³C isotope in water-glycerol and water-trehalose solutions are studied using stationary and pulsed EPR within a wide temperature range. Their magnetic resonance parameters, electron spin relaxation times and rotation correlation times at different temperatures are measured. It is shown that ¹³С-FT radical forms aggregates in trehalose solution, while aggregates are not observed for ¹³С-OX063 radical.

The condensates obtained during wood drying are dilute aqueous solutions of volatile substances and are the closest in their properties to widely known hydrolates. The analysis of the composition of hydrolates is often carried out using their preliminary extraction with organic solvents. However, some hydrophilic compounds may be lost during this procedure, so that analysis results might not correspond to the native composition of the hydrolate. In this work, we have developed a modified technique of GLC analysis with preliminary sample preparation, including the extraction of condensate with an organic solvent, by using an internal standard of hydrophobic nature in the analysis. The developed technique has been tested on hydrolates of ordinary pine wood ( Pinus sylvestris var. mongolica Litv.), but it can also be applied both to condensates obtained during drying of other wood materials and other plant material, and to hydrolates.

The interaction of 4,6-difluoro-, 4-fluoro-, and 2-bromo-4,6-difluorobenzothiazole with BuLi or LiN[(CH₃)₃Si]₂ in tetrahydrofurane, followed by the treatment with dimethylformamide and MeI, revealed the main metalation sites in these model mono- and difluorinated benzothiazoles. The reactivity of the resulting Li-derivatives with respect to formylation and methylation was also characterized.

The content and composition of 19 priority polycyclic aromatic hydrocarbons (PAH) in the rocks and soils of dumps, mushrooms growing on them ( Verpa bohemica and Suillus luteus ), as well as infiltrated and thawed snow waters on the territory of the Gorlovo anthracite deposit were evaluated. It is shown that the main source of PAH in the components of technogenic and adjacent natural landscapes of the deposit are fine coal particles and products of their transformation of non-pyrogenic nature. The flux of PAH into the components of the environment occurs due to: 1) dust fallout near the road along which the extracted coal is transported; 2) transformation of anthracite inclusions in the upper horizons of coal-bearing soils of dumps; 3) migration of transformation products with infiltrated waters. A distinctive feature of the composition of PAH in the samples of the studied objects is the predominance of light PAH (LPAH) in rocks and coals and heavy PAH (HPAH) in infiltrated and thawed snow waters. The composition of the polyarenes of rocks is dominated by PHE (phenanthrene) > FLT fluoranthene) > NAP (naphthalene), waters - FLT > PYR (pyrene) > CHR (chrysene). The composition of PAH of soils depends on the presence of coal inclusions. For carbonaceous soils, the predominant polyarenes are FLT > PYR > PHE = CHR. With depth in soils, the composition of PAHs changes and becomes close to the composition of soil-forming rocks. Mushrooms have a selective ability to absorb PAH. Regardless of the presence of coal in the soils on which the mushrooms grow, the predominant compounds are FLT for V. bohemica and PHE for S. luteus . Based on the results of the analysis of the main components, as well as the correlation of the priority PAH indices with their total content and the content of carcinogenic polyarenes, it has been found that the most representative ratios for assessing the impact of technogenic sources associated with anthracite extraction and transportation are PHE/(PHE + CHR) and ΣLPAH/ΣHPAH.

The anti-inflammatory and analgesic activity of three azaadamantane analogues of amantadine 1 was investigated. The tested azaadamantanes containing nitrogen atoms in the polycyclic framework were: 5,7-dimethyl-1,3-diazaadamantane-6-one 2, 6-amino-5,7-dimethyl-1,3-diazaadamantane 3 and 7-amino-1,3,5-triazaadamantane 4. Experiments were carried out on male mice of CD1 and CBA lines. Compounds were administered intraperitoneally at doses of 20 and 50 mg/kg. Anti-inflammatory activity was studied on the standard models of inflammatory edema induced by histamine or concanavaline inflammation by injecting the phlogogens in the aponeurosis of the hind paw of mice. The analgesic activity was assessed using the hot plate and acetic writhing tests. It is shown that the introduction of heteroatoms into the adamantane core does not reduce the anti-inflammatory activity of diazaadamantanes (2, 3) and enhances that of triazaadamantane (4) compared to amantadine. Modification of the adamantane backbone with nitrogen atoms leads to a change in the analgesic properties of the molecule, which is manifested as hyperalgesia in the acetic writhing test. This phenomenon is presumably related to the effect of azaadamantanes on nocigenic transient receptor potential channels (TRPV1).

Tyrosyl-DNA phosphodiesterases 1 and 2 (Tdp1 and Tdp2) are DNA repair enzymes that are considered as potential targets for antitumour supporting therapy in combination with topoisomerase inhibitors. The most effective Tdp1 inhibitors were found among the derivatives of the lichen secondary metabolite usnic acid. The sensitising effect of these compounds in combination with the topoisomerase 1 inhibitor topotecan was confirmed in cell culture experiments and animal models. In the present work, we describe new derivatives of usnic acid synthesized on the basis of previously obtained Tdp1 inhibitors by introducing the pyrazole cycle annelated with the C ring in dibenzofuran backbone, which makes it possible to reduce the intrinsic toxicity of the obtained compounds. New dual Tdp1 and Tdp2 inhibitors in the micromolar range of concentrations are found.

A new usnic acid derivative containing cyanethyl and isoniazid fragments is synthesised. The compound inhibits the activity of DNA repair enzyme Tdp1 with IC₅₀ = 1.2 μM, is inactive against Tdp2 and does not affect cell survival for a panel of passaged cell lines in the concentration range up to 20 μM. It is shown that the compound in combinations with the certain concentrations of antitumour drugs can sensitise the effect of antitumour drugs olaparib and temozolomide on some cell lines.

15-Acetyl- and 16-acetylfuranolabdanoids were synthesised by the acetylation of the methyl ester of lambertianic acid with acetic anhydride in the presence of Mg(ClO₄)₂ and used as starting compounds for the preparation of 15- or 16-(3-aminopropanoyl)methyllambertianates. The proposed approach involved silylation of 15-acetyl- or 16-acetylmethyllambertianate and the Mannich reaction of the resulting enol silyl ester with N,N-disubstituted methyleneiminium salts. The synthesized compounds possessed cytotoxicity on tumour cell lines CCRF CEM, MCF7 and PC-3 (MTT test). The compounds containing a 3-morpholinopropanoyl or 3-pyrrolidinopropanoyl substituent at the C-16 position of methyl lambertianate selectively inhibited the growth of human T-cell leukemia cells (GI₅₀ was 5.8-6.1 μM) and exhibited cytotoxicity an order of magnitude higher than the parent compound lambertianic acid.

The use of the available synthetic platform of 5-ethynyl-N-(acetyl)anthranilic acid in the synthesis of a chemical library of 2,4-diaryl-3H-1,5-benzodiazepines is proposed. The key step of the synthesis included the reaction of in situ generated methyl 2-acetylamino-5-[3-(4-aryl)propiolyl]benzoate with o-phenylenediamine. The selected conditions were used for the synthesis of a chemical library of 3H-1,5-benzodiazepines containing an anthranilic acid methyl ester fragment in the C-2 position. The physicochemical characteristics of intermediately formed α,β-alkynyl ketones are also described.

The dependence of mechanical characteristics (hardness and tensile strength) of polyurethane on the content of MgFeGa layered triple hydroxide additive and the electron beam irradiation dose is investigated. The optimal amount of layered hydroxides and the optimal irradiation dose, causing a substantial increase in tensile strength and hardness of polyurethane, are determined. Polyurethane modification by adding magnesium/iron/gallium layered triple hydroxides in the amount of 3 wt% causes an increase in tensile strength and hardness by 30.0 and 5.4%, respectively. Modification of pure polyurethane by irradiation with the optimal dose (100 kGy) promotes an increase in tensile strength by 27.1% and hardness by 4.6%.