Russian Journal of Bioorganic Chemistry最新文献

Objective: The research aims to study the efficiency of lignin extraction using a deep eutectic solvent (DES) composed of choline chloride and oxalic acid (0.75 : 1), and to evaluate its effectiveness in wheat straw delignification. Methods: The experiment was conducted within a temperature range of 80–110°C at atmospheric pressure. The cellulose-enriched fraction (technical cellulose), as well as the lignin and hemicellulose fractions, were isolated from the product mixture. Structural changes in the technical cellulose were analyzed using IR spectroscopy and scanning electron microscopy (SEM). Results and Discussion: Increasing the temperature to 110°C resulted in a 83% degree of delignification of wheat straw and a lignin yield of 15.5% dry mass. Alongside delignification, there was a removal of hemicellulose, which led to an increase in cellulose content in the technical cellulose fraction. The SEM images revealed clear morphological changes in the biomass, suggesting that DES effectively cleaved the bonds between the lignin-carbohydrate complex. Conclusions: The study concluded that DES composed of choline chloride and oxalic acid is efficient for delignifying wheat straw, increasing the cellulose content in the technical cellulose fraction and providing insights into the structural changes through SEM analysis.

Objective: This study aimed to analyze the composition of lipophilic components of Caragana jubata (Pall.) Poir. and assess their inhibitory activity against the main protease (3CLpro) of SARS-CoV-2. Methods: The composition of lipophilic extracts from Caragana jubata was investigated using gas-liquid chromatography with mass spectrometric detection (GC-MS). Various extraction methods were employed, including hexane, MTBE (methyl tert-butyl ether), and a combination of both. Extracts were tested for their inhibitory activity against 3CLpro, and the half-maximal inhibitory concentration (IC₅₀) was determined using a fluorescence-based protease assay. Results and Discussion: More than 200 lipophilic compounds were identified, including aliphatic, terpene, and sterol components. Among the extracts tested, the one obtained using MTBE after hexane extraction exhibited the highest inhibitory activity against the SARS-CoV-2 main protease, with an IC₅₀ of 0.05 ± 0.005 mg/mL. The composition of the extracts varied significantly in terms of both the quantity and type of components, with the MTBE extracts showing the most potent bioactivity. Conclusions: The study successfully identified a diverse array of lipophilic components in Caragana jubata, some of which exhibit promising inhibitory activity against the SARS-CoV-2 main protease. The results suggest that Caragana jubata extracts, particularly those obtained with MTBE after hexane extraction, may be a valuable resource for antiviral applications.

Objective: To study the accumulation and seasonal dynamics of glucofructans in the aerial parts of Allium species. Methods: Spectrophotometric analysis of oligo- and polyfructans in leaves and inflorescences of eight Allium species across different phenological phases. Results and Discussion: Polyfructans were high (6.9–10.1%) in spring leaves of A. jesdianum and A. victorialis, but dropped during active growth. In A. victorialis, polyfructans increased again in autumn leaves (9.7–11.8%), suggesting a cryoprotective role. Oligofructans increased during active growth (up to 18.9%), with highest levels in subgenera Melanocrommyum and Anguinum. Conclusions: Fructan content in Allium leaves is species-specific and phenophase-dependent. Taxonomic position affects oligofructan accumulation. High oligofructan content in certain species is promising for food and medicinal applications.

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.