In this work, we optimized the process of sulfating abies ethanol lignin with complexes of sulfuric anhydride with pyridine and 1,4-dioxane. Experimentally found are the conditions for the implementation of the process of sulfation of abies ethanol lignin by complexes of sulfur trioxide with 1,4-dioxane and pyridine, providing a high sulfur content (12.0–12.6%). It was shown that a high sulfur content of 12.0–13.5% (mass.) in the obtained ethanol lignin sulfate is achieved when the ratio of the amount of chlorosulfonic acid to the amount of abies ethanol lignin is 20.22 : 1 mmol : g and the duration of the sulfation process is 60–120 min and independent of the nature of the sulfating complex. The structure and composition of water-soluble sulfated abies ethanol lignin are confirmed by FTIR spectroscopy, gel permeation chromatography and elemental analysis. In the FTIR spectra of sulfated abies ethanol lignin, in comparison with the FTIR spectra of the initial abies ethanol lignin, there are absorption bands in the region of 1270–1260, 1220–1212, 861–803 cm-1, corresponding to vibrations of sulfate groups. Compared to the initial lignin, sulfated abies ethanol lignin has a low degree of polydispersity. In particular, there was an increase in Mw c ~1.5 kDa to ~3.4 kDa in lignin sulfated for 30 min and a decrease in polydispersity from 2.59 to 1.22 compared to the initial abies ethanol lignin. With an increase in the sulfation time, the profile of the molecular mass distribution curve shifts to a high molecular weight region, with a simultaneous increase in polydispersity to 1.5 and Mw increases to ~4.3 kDa.

The effect of the conditions of the acetylation process of raw and activated birch bark on the yield and composition of the products is investigated. The structure of biologically active betulin diacetate (BDA) is confirmed with physicochemical methods. The optimal regimes of the one-step original method for the production of BDA from raw and activated birch bark are established using the experimental and computational techniques.

The new process of abies ethanol lignin sulfation by a low-toxic mixture of sulfamic acid and urea in 1,4-dioxane medium was optimized, and the structure of sulfated ethanol lignin was studied. The process of lignin sulfation is described by a first-order equation in the temperature range 70–100 °C. The value of the rate constants is weakly dependent on the ratios of lignin and sulfating complex (sulfamic acid–urea mixture). The activation energy of the sulfation process decreases from 11.5 to 7.5 kJ/mol with an increase in the content of the sulfating complex (SC). The optimal conditions for sulfation of abies ethanol lignin with a high yield of water-soluble sulfated lignin [(100% of mass) with sulfur content of 7.9%] were found: temperature 95–100 °C, L/SC ratio 1:2.3–1:2.9, time 2 h. The composition and structure of water-soluble sulfated ethanol lignin were determined by elemental analysis, FTIR spectroscopy, two-dimensional NMR spectroscopy and gel permeation chromatography. It was shown that only alcoholic OH groups of ethanol lignin react with sulfamic acid. Sulfated ethanol lignin has a higher molecular weight and a lower degree of polydispersity compared to the initial ethanol lignin.

The possibility of using aspen bark modified with zinc and iron chlorides for preparing highly porous materials with specific properties was examined. The effect of the treatment temperature and modifiers on the structural and electrochemical parameters of the carbon-containing product was revealed. Carbonization of aspen bark modified with ZnCl2 yielded a material with the specific surface area of up to 1350 m2 g–1, containing a crystalline zinc oxide phase. The material obtained using a mixture of aspen bark with FеCl3 had the specific surface area of up to 300 m2 g–1 and contained magnetite and maghemite. Modification of the bark with zinc and iron chlorides simultaneously yielded a highly porous product with ferromagnetic properties. The apparent capacitance of the samples carbonized at 800°С was found to be 150–400 F g–1. The possibility of using these materials in electrochemical devices was suggested.

A method is developed for the production of enterosorbent from the birch inner bark with supported biologically active betulin with improved therapeutic and prophylactic properties.

Method is suggested for obtaining biochar materials by treatment of a finely dispersed (≤0.1 mm) bark of aspen and(or) larch with a 40% formaldehyde solution and subsequent thermal activation of the activated bark. It was found that keeping the composite at a temperature of 50–80°C for three days makes the binding process complete. Further carbonization at temperatures of 350–900°C yields a biochar with bulk structure. The method of IR spectroscopy confirmed that the functional composition of bark changes under the action of a cross-linking agent and — CH2 — bonds are additionally formed. It was found that the larch bark containing lignins of predominantly G-type and condensed tannins is more suitable for obtaining porous biochar materials (with specific surface area of 94–161 m2 g−1) as compared with the aspen bark. The adsorption properties of biochar materials produced from the modified bark in removal of Cu(II) ions from aqueous solutions. It was found that, on being carbonized at 900°C, a sample of modified aspen bark can extract 122.9 to 220 mg g−1 of copper compounds on raising the sorption temperature from 25 to 45°C.

For the first time, the synthesis of water-soluble copper-containing microcrystalline cellulose sulfates (Сu-MCS) has been performed by the ion exchange method. The composition of the products has been studied by chemical methods and X-ray spectral microanalysis. The copper content in the Сu-MCS samples was 12.6–14.1%. The absence of sodium in the resulting polymer indicates the complete substitution of the sodium cations by the copper cations in the sodium salt of MCC sulfate. The structure of the copper-containing sulfates of microcrystalline cellulose has been confirmed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and electron paramagnetic resonance (EPR). According to the XRD method, Сu-MCS and Na-MCS have an amorphous structure in contrast to the original MCC samples, which have a high degree of crystallinity. The EPR data have demonstrated the formation of a pseudocrystalline structure of the copper-containing salt system in the Сu-MCS samples. As shown by atomic-force microscopy, the surface of the Сu-MCS films consists of homogeneous crystallites, which have a spherical or slightly extended form with the size of about 70 nm. The film surface is quite homogeneous in its phase composition and contains no impurities.

A new method for preparation of organic aerogels by sol–gel polymerization of formaldehyde with polyphenols (PPs), isolated from larch bark and birch bark, was developed. The functional composition and properties of the original polyphenols were studied by thermogravimetric methods and FTIR spectroscopy. It was found that larch polyphenol material had higher thermal stability in the temperature range 25−700°C, while the process of thermal decomposition of birch bark polyphenols completes at 600°C. It has been established that polyphenol larch compounds contain more aromatic structures and hydroxyl groups. The effect of the pH of gelation solutions in the range from 4 to 12 on the porous structure of organic gels synthesized from polyphenols was studied. The porous structures and adsorption properties of polyphenol-formaldehyde organic gels were studied using the BET method, scanning electron microscopy and sorption (methylene blue and gelatin). It was shown that an increase in pH contributes to the formation of a product with a more compacted texture. The electron microscopic images of polymer gels demonstrate a uniform granular texture with visible microglobules with an average particle size of ≈50−70 nm.

Synthesis of water-soluble copper-containing sulfates of arabinogalactan was carried out for the first time by the ion exchange method. Their composition and structure were studied by the methods of elemental and chemical analysis, X-ray spectral microanalysis, atomic force microscopy (AFM), infrared spectroscopy (FTIR), and electron paramagnetic resonance (EPR). According to the AFM data, the surface of copper-containing polymer films does not have inclusions and consists of homogeneous crystallites of a spherical and slightly elongated shape and transverse dimensions of about 100 nm. The composition of copper- containing polymers was studied by the chemical method and X-ray spectral microanalysis. The absence of nitrogen in the obtained polymer indicates the complete replacement of ammonium cations in the ammonium salt of AG sulfate with the copper cations. The IR spectrum of copper-containing AG sulfate is similar to that of the sodium salt of sulfated arabinogalactan. Superposition of two signals was observed in the EPR spectrum of copper-containing AG sulfate. One of them belongs to isolated Cu2+ ions; another, to associated Cu2+ ions in the salt-like compounds. The integral intensity of isolated Cu2+ ion signals (anisotropic signal) and associated ions (isotropic signal) depends on the copper content in the polymer. Water-soluble coppercontaining polymers of AG sulfates have prospects for their use in medicine.

The sulfation of arabinogalactan (AG) by sulfamic acid in the presence of urea in dioxane has been studied. The degree of AG sulfation increases as the sulfation temperature increases from 70 to 95°C. As indicated by 13C NMR spectroscopy, the sulfate groups in sulfated AG are in the C2 and C4 positions of the main galactan chain and the C6 position of the terminal galactose units of the main and the side chains of AG. The sulfation of AG by the complex sulfamic acid–urea in dioxane medium makes it possible to increase the ecological safety and the efficiency of the process compared with the known methods of sulfation.

Betulin-containing products were obtained in a yield of about 40% from absolutely dry birch bark. The content of betulin in the products was 74–75% or 85–89% depending on the presence of sodium or potassium hydroxide, respectively. The one-step method of extraction of high-purity betulin (97.7%) is presented. Betulin was identified by physic-chemical methods, i.e., elemental analysis, IR and NMR spectroscopy, and electron scanning microscopy. The thermal characteristics of betulin were also studied. It was shown that betulin exhibits gastroprotective, hepatoprotective, and capillary-strengthening properties.

A one-step synthesis of the betulin dipropionate directly from the birch bark without a separate stage of the betulin preparation is described in this paper. Extracts with different content of the betulin dipropionate were shown to form depending on the conditions of acylation of the upper birch bark with propionic acid. The product with the maximum content of the betulin dipropionate was prepared from the starting fraction of 2–5 mm of the upper birch bark and the fraction of 10–20 mm that was preliminarily activated with superheated water vapor. The upper bark extract was analyzed by gas chromatography. The structure of betulin dipropionate was confirmed by element analysis, 1 H NMR, 13 C NMR, and FTIR spectroscopy.

The influence of mechanical treatment on the properties of betulin, betulin diacetate, and their mixture with water-soluble polymers was studied. It was shown that mechanical treatment in a planetary mill-activator disordered the crystalline structure of betulin and betulin diacetate. Composites of betulin with polyvinylpyrrolidone (PVP) and polyethyleneglycol (PEG) that gave an increased betulin concentration upon dissolution in water were prepared. It was shown that H-bonds formed between betulin and PVP upon mechanical activation of their mixtures.

Methods of synthesis of betulin diacetate and di propionate from birch bark are proposed. The methods are based on combined extraction of betulin from birch bark and its acylation with acetic and propionic acids. The structure of the resulting betulin derivatives was confirmed by means of chromatography-mass spectrometry, FT-IR and NMR spectroscopy.

We have studied in vitro the ability of the Siberian cedar crust (SCC) extract (Pinus sibirica Du Tour) and arabinogalactan sulphate (AGS) extracted from wood of Siberiam pine-tree (Larix sibirica Ledeb.) to increase the human blood plasma coagulation time and also to inhibit the amydolytic activity of thrombin (aIIa) and the coagulation factor Xa (aXa). A method has been developed by means of which SCC increases the aXa activity by a factor of 3.7 and the aIIà activity by a factor of 2.5. The AGS preparation increased the blood plasma coagulation time in the test for activated partial thromboplastin time. An effective concentration, at which the time of plasma coagulation was increased by a factor of 2 (in comparison to the control) was 2.94 +/- 0.33 mg/ml. AGS did not exhibit the ability to inhibit the Xa activity.