Efficient Method for the Preparation of Pure,Water-Soluble Cellodextrines

An efficient method towards water soluble cellodextrine mixtures is described and detailed information on structure analysis is given. For cellulose degradation in good yield, treatment of cellulose with 85% phosphoric acid for 30 minutes at room temperature and a hydrolysis of 20 hours at 55 °C are suitable. With a work up in tetrahydrofuran (THF), a yield of almost 70% raw product is achievable. After separation of a water insoluble fraction, a yield of 53% of cellodextrines with a degree of polymerization (mean weight average, ) of 7.5 and a polydispersity index of 1.7 is obtained. These cellodextrines are soluble in water, dimethyl sulfoxide (DMSO) and dimethyl acetamide (DMA)/LiCl. Detailed structure analysis by one and two-dimensional NMR, FTIR and mass spectroscopy revealed that the substance consists only of β-1 → 4 linked glucoses. A partial functionalization was excluded by ¹³C NMR- and ³¹P decoupled ¹H NMR spectroscopy.