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A comparison of IR spectra and molecular weight distribution of arabinogalactan sulfates as sodium and ammonium salts obtained using various sulfating reagents was performed. According to the data, sulfated derivatives of arabinogalactan differ from each other in the nature of hydrogen bonds and molecular weight distribution. Using coagulological tests during activation of coagulation of platelet-poor human plasma in vitro, the anticoagulant properties of sulfated arabinogalactan derivatives in various salt forms differing in the preparation method, sulfation degree, and molecular weight were studied. It was found that the sample in the form of the sodium salt of sulfated arabinogalactan (SAG 1) with a sulfur content of 13.2 wt % and a polydispersity degree of 1.52 exhibited twofold greater anticoagulant activity than the sample in the form of the ammonium salt of sulfated arabinogalactan (SAG 2) with a sulfur content of 6.6 wt % and a polydispersity degree of 1.30. The antithrombin (aIIa) activity of the samples obtained by sulfation with a complex of pyridine and sulfuric anhydride (SAG 1) and a complex of sulfamic acid (SAG 2) was 23.42 ± 1.86 and 10.20 ± 1.50 U/mg, respectively; the value of the antifactor Xa activity of SAG 1 and SAG 2 was 2.13 ± 0.42 and 0.37 ± 0.08 U/mg; the aIIa/aXa ratio for SAG 1 and SAG 2 was 11 and 28, respectively. The antifactor Xa (aXa) activity of SAG, which is lower than that of unfractionated heparin (UFH), and a high aIIa/aXa activity ratio may contribute to less provocation of bleeding by SAG samples compared to UFH.

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.

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 structure of sodium salts of arabinogalactan (AG) sulfates obtained by sulfating AG of larch wood with a sulfamic acid–urea mixture in 1,4-dioxane was studied by the methods of Raman spectroscopy, X-ray diffraction (XRD) phase analysis, scanning electron microscopy (SEM), and atomic force microscopy (AFM). The introduction of sulfate groups into the structure of arabinogalactan was confirmed by the appearance in the Raman spectra of new absorption bands related to the deformation vibrations δ (SO3) at 420 cm–1 and δ (О=S=O) at 588 cm–1, stretching vibrations ν (C–O–S) at 822 cm–1, symmetrical stretching vibrations νs (O=S=O) at 1076 cm–1, and asymmetric stretching vibrations of νas (O=S=O) at 1269 cm–1. According to the XRD data, the amorphization of arabinogalactan structure occurs during the sulfation process. The SEM method revealed a significant difference in the morphology of the sulfated and starting arabinogalactan. The starting AG consists of particles of predominantly globular shape with a size of 10 to 90 μm; arabinogalactan sulfates, of particles of various shapes with sizes of 1–8 μm. According to the AFM, the surface of sulfated arabinogalactan film consists of rather homogeneous spherical particles about 70 nm in size. The root-mean-square value of the surface roughness is 33 nm. The surface of sulfated AG film does not contain impurities.