Synthesis of thiolated xyloglucan
The covalent attachment of xyloglucan to thioglycolic acid was
achieved by ester bonds formation between hydroxyl group of
beta-galactane moieties of xyloglucan and carboxyl group of thioglycolic
acid (Fig. 1).
After complete drying, product appeared as off-white odorless
powder, soluble in water. The average yield of this synthesis
amounted to 48% of the utilized amount of xyloglucan. Thioglycolic
acid is soluble in water and methanol. Precipitation with methanol
from an aqueous solution and subsequent washing by keeping
the precipitate over night was found to be sufficient purification
method for thiolated xyloglucan. Thiolated xyloglucan was found
to contain 4 mmol of thiol groups/g as determined by quantifying
the amount of thiol group by Ellman’s method.