Polysaccharides are important structural components of all plant species. Gel-like polysaccharides have found wide application in various fields, including medicine, construction, and the food industry. In the present work, galactomannan and galactoglucomannan gel-like polysaccharides were modified with sulfate groups and their anticoagulant activity was studied. Sulfation with chlorosulfonic acid in pyridine and with sulfamic acid in pyridine and a sulfamic acid–urea deep eutectic solvent were used as synthesis routes. The resulting gel-like polysaccharide sulfates were studied by elemental analysis, Fourier-transform infrared spectroscopy, and gel permeation chromatography. It was established that the anticoagulant effect of sulfated galactoglucomannan (SGGM) and galactomannan (SGM-1 and SGM-2) is related to an independent antithrombin-independent decrease in the amidolytic activity of thrombin and factor Xa. It is shown that the inhibitory activity of SGGM and SGM-2 against the collagen-induced platelet aggregation can be an additional factor in selecting compounds that are most promising for modifying polymer surfaces to ensure resistance to blood clotting.

Кора березы содержит экстрактивные вещества лупанового ряда, обладающие фармакологической активностью и представляющие интерес для получения новых лекарственных препаратов. Преобладающим компонентом экстрактов внешней коры березы является пентациклический тритерпеновый спирт – бетулин. Аллобетулин (19,28-эпокси-олеанан-3-ол) является изомером бетулина и относится к пентациклическим тритерпеноидам олеананового ряда. Аллобетулин и его производные нетоксичны и обладают противовирусной, противомикробной и противоопухолевой активностями. Разработан новый одностадийный способ получения аллобетулина непосредственно из бересты коры березы путем совмещения стадий экстракции бетулина этанолом и его изомеризации в аллобетулин в присутствии катализатора ортофосфорной кислоты. Установлено влияние продолжительности процесса обработки бересты этанолом и содержания H₃PO₄ на выход аллобетулина. Наибольший выход неочищенного аллобетулина (35% от массы а.с.б.) достигается при продолжительности процесса 8 ч в присутствии 5% H₃PO₄, а также при продолжительности 15 ч в присутствии 3% H₃PO₄. Выход перекристаллизованного аллобетулина составляет около 22% от массы а.с.б. Состав образца аллобетулина после перекристаллизации из изопропанола подтвержден методом элементного анализа, а его строение – методами ИК- и ¹Н ЯМР-спектроскопии. В экспериментах in vivo и in vitro установлены антиоксидантные свойства аллобетулина.

Changes in the morphology of betulin crystals during heating at selected temperatures corresponding to polymorphic transformations were investigated. It was shown that the prismatic crystals of starting betulin form III were converted into needles at 120 °C after water removal, followed by the III→II polymorphic transformation. During further heating up to 180 °C, the whiskers of betulin form I were grown. Experiments on betulin heating in the presence of dicarboxylic acids, adipic or suberic showed that the morphological changes can serve as a test for the formation of cocrystals. According to morphological changes, the formation of cocrystals of betulin with adipic acid under heating was identified. The interaction of adipic acid vapor with the surface of betulin crystals was suggested. In contrast, morphological changes in the mixture of betulin and suberic acid under heating provided only the evidence of polymorphic transformations of the components. The results on cocrystal formation by heating were compared with the preparation of cocrystals by the liquid-assistance grinding method. Despite the fact that polymorphic forms with a high surface area were formed when betulin was heated, dissolution studies showed that the starting betulin polymorph III exhibited the highest dissolution rate in comparison with betulin polymorphs obtained under heating.

The aim of this work was the mathematical modeling and selection of optimal regimes for the process of biologically active betulin dipropionate production based on the treatment of birch bark by propionic acid. In order to achieve this aim, two variable factors of the process were varied: X1 – the average size of bark particles (3.5 and 15.0 mm); X2 – the duration of the process. The output parameters were: Y1 – product yield (as a percentage by mass of the absolutely dry bark); Y2 – mass fraction of betulin dipropionate in the product (in percent); Y3 – the yield of betulin dipropionate as a percentage by mass of the absolutely dry bark. For mathematical processing of the results, the Statgraphics Centurion XVI package, the DOE block, the Multi-Factor Categorical procedure were used. It was established by experimental and computational methods that the optimal conditions for obtaining the product with the highest content of betulin dipropionate are as follows: a ratio liquid/solid of 20, an average size of bark particles of 3.5 mm, a time of 8–12 hours. The structure of betulin dipropionate, obtained under optimal conditions, was confirmed by physicochemical methods, the purity of the product was 95%. Due to its low toxicity and valuable pharmacological properties the betulin dipropionate has prospects for use in medicine.