Russian Journal of Bioorganic Chemistry最新文献

Objective: To synthesize organic xerogels from Siberian cedar bark tannins and study the effect of different crosslinking agents (formaldehyde, furfuryl alcohol, glutaraldehyde) on their properties. Methods: Xerogels were prepared by sol-gel condensation and characterized using density measurements, FT-IR, BET analysis, SEM, and TGA. Methylene blue sorption was tested. Results and Discussion: The crosslinking agent defined the gel structure. The tannin-furfuryl alcohol (T/FA) xerogel was microporous and dense (0.348 g/cm³), while tannin-formaldehyde (T/F) and tannin-glutaric (T/G) xerogels were meso/macroporous with low density (~0.07 g/cm³). T/FA was the most thermally stable (onset decomposition at 282°C). The T/F xerogel showed the highest methylene blue sorption capacity (107 mg/g). Conclusions: Cedar bark tannins are a promising raw material for producing xerogels. The crosslinking agent type allows control over the porosity, density, thermal stability, and sorption properties of the final material.

Objective: The study explores the electrophysical properties of lignins, specifically focusing on their potential applications due to their polyfunctional aromatic nature, conjugation system, and high reactivity in redox interactions. The research aims to investigate the relationship between the functional nature, reaction properties, and dielectric properties of lignins. Methods: The study involved slightly altered dioxane lignin from spruce and modified lignin samples with varying contents of carbonyl and methoxyl groups. The redox and dielectric properties were analyzed, including the effects of functional group content on oxidation potential, electrical conductivity, and complex permittivity. Dielectric spectroscopy was used to measure the conductivity and permittivity in a frequency range of 10^–2 to 10⁷ Hz, and the frequency dependences of the complex permittivity were analyzed to identify relaxators in the lignin structure. Results and Discussion: It was found that changes in the content of carbonyl groups significantly influenced the redox properties of lignin, with the effective oxidation potential of phenolic units varying by up to 24 mV. The study also showed that the carbonyl and methoxyl groups affected the real part of the complex permittivity at low frequencies (less than 1 Hz), suggesting that these changes influenced the dielectric properties of lignin. The results indicate that lignin could be a promising material for broadband electrical capacitors. Conclusions: The study concluded that the functional nature of lignin, including the content of carbonyl and methoxyl groups, significantly affects its dielectric and redox properties. These findings suggest that lignin is a promising material for the manufacture of broadband electrical capacitors.

Objective: To compare the efficiency of subcritical water vs. ethanol-water solutions for extracting components from rosemary leaves. Methods: Rosemary leaves were extracted using ethanol-water solutions (10–95%) via maceration/reflux and with subcritical water (130–150°C). Extracts were analyzed by GC-MS, both directly and after derivatization. Results and Discussion: About 100 components were identified. Ethanolic solutions were superior for extracting volatile terpenoids (e.g., camphor, borneol). Subcritical water at 150°C was most effective for non-volatile compounds, yielding the highest content of rosmarinic acid and other phenolic/carboxylic acids. Extraction efficiency for non-volatiles increased with temperature. Conclusions: 95% ethanol is optimal for volatile compound extraction, while subcritical water at 150°C is best for non-volatiles like rosmarinic acid. Subcritical water is a viable green method for obtaining bioactive compounds from rosemary.

This review provides information on the systematics, distribution, composition of metabolites, and biological activity of plants of the Taxaceae S.F.Gray family, comprising eight genera. According to taxonomists, the family has 30–35 species, most of which are endemic to Asia. Across the globe medicine, since the 1990s, the Taxaceae family has been known for the preparations Paclitaxel®, Docetaxel®, and Synribo® with antitumor effect, produced from some species of this family. In traditional Indian (Ayurveda) medicine, Tibetan medicine, and Chinese medicine, various parts of Taxus baccata, Taxus wallichiana, Cephalotaxus hainanensis, Cephalotaxus mannii, and Torreya grandis are used. The most extensively studied are the antitumor properties and composition of metabolites of some of the 17 species of the Taxaceae family: Taxus brevifolia, Taxus baccata, Taxus cuspidata, Taxus wallichiana, Taxus yunnanensis, Torreya nucifera, Torreya grandis, Cephalotaxus wilsoniana, Cephalotaxus sinensis, Cephalotaxus oliveri, Cephalotaxus lanceolata, Cephalotaxus koreana, Cephalotaxus harringtonia, Cephalotaxus hainanensis, Cephalotaxus griffithii, Cephalotaxus fortunei, and Amentotaxus formosana. In the studied species, over 900 substances belonging to different classes of chemical compounds were identified: alkaloids, terpenoids, fatty acids, phenolic compounds (simple phenols, phenolic carboxylic acids, flavonoids, tannins), vitamins, lignans, sterols, amino acids, etc. An important marker of the family is probably taxane diterpenes, which were found in the 17 species of the Taxaceae family. According to the literature, this group of substances, as well as alkaloids, are decisive in the antitumor effect exerted by Taxaceae family species. Extracts and individual substances in the experiment in vivo, in vitro, and in silico display a broad range of pharmacological activity: antitumor, antiproliferative, cytotoxic, antioxidant, anxiolytic, antinociceptive, antiosteoporotic, anti-inflammatory, antibacterial, antiviral, neuroprotective, hypoglycemic, etc. The information presented in this review shows that plants of the Taxaceae family and their individual metabolites are promising for further study.

Objective: This study aims to analyze the varietal differences in kiwi fruits with respect to the accumulation of bioactive compounds, such as anthocyanins, chlorophyll, carotenoids, and polyphenols. These compounds are known for their antioxidant properties and are essential for the nutritional value of the fruit. Methods: A spectrophotometric method was used to determine the levels of bioactive compounds in kiwi fruits from five different varieties: Pobeditel, Otkhara, Apsny, Gulripshsky, and Slava. Anthocyanins, photosynthetic pigments (chlorophylls and carotenoids), and polyphenols were quantified by measuring the optical density at specific wavelengths. Statistical analysis was conducted using one-way ANOVA to compare the differences in compound content among the varieties. Results and Discussion: The study found significant differences in the bioactive compound content across the varieties. Anthocyanins were predominantly represented by pelargonidin-3-glucoside, with the highest content in the Pobeditel variety (72.7–79.0 mg/100 g). Carotenoid content ranged from 0.191 to 0.416 mg/100 g, with the highest concentrations in the Gulripshsky and Otkhara varieties. Polyphenols were found to be most abundant in the Pobeditel and Gulripshsky varieties, with concentrations ranging from 951.9 to 1576.5 mg/100 g. The results highlight the antioxidant potential of these varieties and their nutritional significance. Conclusions: The kiwi varieties Pobeditel, Gulripshsky, and Otkhara, which are distinguished by their high content of anthocyanins, carotenoids, and polyphenols, are identified as promising candidates for further breeding efforts aimed at producing fruits with enhanced antioxidant properties. These varieties offer significant nutritional value and could have broader appeal to consumers interested in antioxidant-rich foods.

Objective: The study aims to investigate the qualitative and quantitative composition of essential oils from the seeds of Siberian fir (Abies sibirica), as no previous publications exist regarding the essential oil composition of the seeds of this coniferous species. Methods: The essential oil composition was analyzed using gas-liquid chromatography (GLC) and chromatography-mass spectrometry (GC/MS). The yield of essential oil was determined as a percentage of the absolute dry weight of the seeds. Results and Discussion: The yield of essential oil was found to be 4.3% of the absolute dry weight of the seeds. A total of 49 components were identified, making up 98.5% of the essential oil mass. Monoterpenes and their oxygen-containing derivatives were the major constituents, with the dominant components being α-pinene (36.7%), boronyl acetate (18%), β-pinene (11.1%), and camphene (10.9%). Sesquiterpenes accounted for 3.2%, while diterpenes made up 2.4% of the oil. Among the sesquiterpenes, bisabolol was the most prevalent (0.69%), and among the diterpenes, abietal was dominant (1.1%). Notably, a group of diterpenes was present in the essential oils of the seeds, in contrast to the essential oils of Siberian fir needles. Conclusions: The essential oil of Siberian fir seeds contains a diverse array of compounds, with monoterpenes as the major group. The presence of diterpenes in the seed oil, absent in the needle oil, is a significant finding, highlighting the unique chemical profile of Siberian fir seed essential oils.

Objective: The purpose of this study was to investigate the accumulation of natural and artificial radioisotopes in medicinal plant raw materials, specifically examining greater plantain (Plantago major L.) leaves harvested from various territories of the Voronezh region, which differ in anthropogenic impact. Methods: The specific activity of long-lived artificial radionuclides (cesium-137, strontium-90) and natural radionuclides (thorium-232, potassium-40, radium-226) was measured in soil and greater plantain leaves using an MKGB-01 RADEK spectrometer-radiometer. Samples were collected from diverse areas with varying levels of industrial, agricultural, and urban influences. Correlation analysis and accumulation coefficients were used to assess the transfer of radionuclides from soil to plant. Results and Discussion: The results indicated that all collected greater plantain samples complied with radiation safety standards. Cesium-137 and strontium-90 were present in higher concentrations than natural radionuclides, but all levels were within permissible limits. A strong correlation between the radionuclide content in soil and plant leaves was observed, confirming that the contamination primarily occurs through soil. Accumulation coefficients for cesium-137 ranged from 1.81 to 3.29, with an average of 2.55. The study also identified trends of decreased accumulation with increased radionuclide concentrations in the soil, suggesting physiological mechanisms regulating radionuclide uptake. Conclusions: Greater plantain leaves from the Voronezh region accumulate radionuclides primarily through soil contamination. The study confirms that the leaves meet radiation safety standards for medicinal plant raw materials. Accumulation of cesium-137 was notably high, while other radionuclides showed lower levels. The results highlight the importance of monitoring radionuclide contamination in medicinal plants, particularly in urbanized and industrialized areas.

Objective: This study aimed to analyze the biochemical composition of aspen wood (Populus tremula L.) in relation to infestation by aspen tinder (Phellinus tremulae), to identify aspen forms resistant to rot. Methods: Wood samples were collected from an aspen stand in the Molokchinsky Botanical and Entomological Reserve. The Py-GC/MS method was used to analyze the molecular structure of the wood. Results and Discussion: Healthy aspen wood had a higher content of polysaccharide pyrolysis products compared to wood with tinder and rot. Aspen trees with tinder fruiting bodies but no rot showed increased lignin pyrolysis products, indicating possible resistance to rot. Conclusions: The biochemical composition of aspen wood, particularly the ratio of polysaccharides to lignin, affects its resistance to rot. Pyrolysis products like syringol and 4-vinylguaiacol may serve as markers for wood resistance.

Objective: To optimize ultrasound-assisted extraction of carotenoids, polysaccharides, and flavonoids from Cordyceps militaris mycelium. Methods: Biomass was cultivated on grain substrates. Extraction used water-ethanol mixtures (20–80%) at 30–60°C with ultrasound (150 W, 28 kHz) for 10–40 min. Compound content was determined spectrophotometrically. Results and Discussion: Optimal parameters were 70% ethanol, 60°C, and 30 min. The highest yields of carotenoids (up to 3.22%), polysaccharides (up to 17.65%), and flavonoids (up to 30.56%) were obtained from mycelium grown on brown rice. Ultrasound extraction outperformed Soxhlet extraction, providing higher BAC yields in a significantly shorter time. Conclusions: Ultrasound-assisted extraction is an efficient method for obtaining Cordyceps militaris extracts rich in bioactive compounds. Brown rice is the preferred substrate, and the optimized process is suitable for producing ingredients for food and pharmaceutical industries.

Objective: The study aims to investigate the one-pot production of xylitol from xylan, comparing it to traditional methods that involve xylan depolymerization to xylose followed by reduction to xylitol. The goal is to improve environmental and economic aspects by eliminating intermediate stages of purification and raw material preparation. Methods: Bifunctional catalysts containing nanodispersed ruthenium particles (0.5–3%) on Sibunit-4 carbon support with varying acidity (oxidized by a wet air mixture at 400–500°C) were synthesized and characterized. The study separately examined xylan hydrolysis and xylose hydrogenation using Ru-containing carbon catalysts. The effects of support acidity and ruthenium content on the yield of hemicellulose hydrolysis and monosaccharide hydrogenation products were studied. Results and Discussion: It was found that the most active catalyst for both xylan hydrolysis and xylose hydrogenation was 2RuSib450, which had the support oxidized at 450°C, providing the maximum acidity, and 2 wt% Ru. In the one-pot process using this catalyst, the hydrolysis reaction proceeded more slowly than xylose hydrogenation, with significant amounts of propylene glycol and ethylene glycol produced, indicating low selectivity for xylitol. The yield of xylitol did not exceed 6 wt%. However, in the one-pot process involving hydrolysis-transfer hydrogenation with a combination of H₂SO₄ and 2RuSib450 in an isopropanol-water medium, xylitol was obtained with a high yield of 88 wt%. The use of a small amount of H₂SO₄ allowed the process to be carried out in standard stainless-steel equipment, instead of requiring equipment made from alloys with high nickel content. Conclusions: The study demonstrates that the one-pot process for xylitol production from xylan using the 2RuSib450 catalyst and H₂SO₄ in an isopropanol-water medium can achieve high yields of xylitol (88 wt%), offering an environmentally friendly and economically attractive alternative to traditional methods. The process also benefits from using standard stainless-steel equipment, reducing the need for specialized materials.