HPLC AND C-13-NMR STUDY OF OXYMETHYL-BETA-(1-]6)-D-GLUCO-BETA-(1-]3)-D-GLUCAN DERIVED FROM SACCHAROMYCES-CEREVISIAE

Sodium salt of carboxymethyl-beta-(1 --> 6) -D-gluco-beta-(1 --> 3) -D -glucan (CMG-Na) was prepared from beta-D-glucan isolated from baker's yeast (Saccharomyces cerevisiae). Three samples, Fractions I, II, and III, were further separated from the crude CMG-Na derivative. For the physicochemical characterization of the separated fractions, the meth ods of high-performance liquid chromatography (HPLC) in the size-exclu sion mode and carbon-13 nuclear magnetic resonance (C-13-NMR) spectros copy were applied. The HPLC method revealed that the molecular weights , M(n), M(w), and M(z) averages, of Fraction II were 9.71 X 10(4), 2.2 7 X 10(5), and 3.59 X 10(5) Da, respectively, whereas those of Fractio n III were 1.52 X 10(4) , 2.13 X 10(4), and 3.57 X 10(4) Da, respectiv ely. The C-13-NMR spectra of Fraction II showed a ratio of 3 : 1 for b eta-(1 --> 3)/beta-(1 --> 6), whereas for Fraction III, the content of beta-(1 --> 3) units was smaller.