Publications by authors named "Natalya Yu Vasilieva"
Soda lignin is a by-product of the soda process for producing cellulose from grassy raw materials. Since a method for the industrial processing of lignin of this type is still lacking, several research teams have been working on solving this problem. We first propose a modification of soda lignin with sulfamic acid over solid catalysts.
View Article and Find Full Text PDFArticle Synopsis
- Betulin, a bioactive triterpenoid from birch bark, can be sulfated using a new method involving sulfamic acid and an Amberlyst-15 catalyst, achieving stable results over multiple cycles.
- Various spectroscopy techniques (FTIR, UV-Vis, NMR) confirm the successful sulfation of betulin, showing distinct shifts and absorption patterns in the resulting sulfated product.
- Thermal analysis reveals that both betulin and its sulfated version are stable at high temperatures, while computational methods provide detailed insight into their molecular properties and behaviors.
Xanthan is an important polysaccharide with many beneficial properties. Sulfated xanthan derivatives have anticoagulant and antithrombotic activity. This work proposes a new method for the synthesis of xanthan sulfates using sulfamic acid.
View Article and Find Full Text PDFArticle Synopsis
- The study focuses on synthesizing guar gum sulfates using a sulfur trioxide-1,4-dioxane complex and examines factors like temperature, duration, and chlorosulfonic acid volume affecting substitution degree.
- The optimal conditions determined for the sulfation process are 60 °C, 2.9 hours duration, and 3.1 ml volume of chlorosulfonic acid, confirmed through various analytical techniques including elemental analysis and FTIR.
- Additional characterization methods like X-ray diffraction showed a change in the structure of guar gum due to sulfation, while scanning electron microscopy and gel permeation chromatography revealed alterations in morphology and a significant reduction in molecular weight from 600 to 176 kDa.