The Application of Various Protic Acids in the Extraction of (1 → 3)-β-D-Glucan From Saccharomyces Cerevisiae
Document Type
Article
Publication Date
4-21-1997
Description
Glucans are (1 → 3)-β-linked glucose polymers which have immune-stimulating capability. The extraction of water-insoluble (1 → 3)-β-D-glucan form Saccharomyces cerevisiae employs hydrochloric acid. Hydrochloric acid is difficult to employ in the large-scale pharmaceutical extraction of glucans due to its corrosive nature and toxicity. To address these concerns, we determined whether acetic, formic or phosphoric acid can be substituted for hydrochloric acid in the process for the isolation of (1 → 3)-β-D-glucan. The resulting microparticulate glucans were employed as the starting material for the production of (1 → 3)-β-D-glucan phosphate. 13C NMR analysis of the glucan phosphates derived from the acetic, formic or phosphoric acid-extracted microparticulate glucan show excellent correspondence to hydrochloric acid extracted glucan and laminarin, a (1 → 3)-β-D-glucan standard, indicating that the primary structure is not altered by the acid used for extraction. Glucan phosphate prepared from hydrochloric acid had a M(W) of 7.2 x 104 g/mol, rms(Z), of 17.7 nm, of 1.50 and (η) of 49.0 mL/g. Glucan phosphate prepared from acetic acid had a primary polymer peak with a M(W) of 1.4 x 106 g/mol, rms(Z) of 23.6 nm, I of 1.93 and (η) of 62.4 mL/g. Glucan phosphate prepared from formic acid had a main polymer peak with a M(W) of 1.2 x 106 g/mol, rms(Z) 27.1 nm, I of 1.56 and (η) of 89.0 mL/g. Glucan phosphate prepared from phosphoric acid had a primary polymer peak with a M(W) of 6.6 x 105 g/mol, rms(Z) of 32.3 nm, I of 2.70 and (η) of 91.3 mL/g. These data indicate that the molecular mass, size, polydispersity and intrinsic viscosity of the glucan phosphate obtained is influenced by the pK(a) of protic acid employed to extract the microparticulate glucan. However, the primary structure and side-chain branching are not substantially altered regardless of the acid employed.
Citation Information
Müller, Antje; Ensley, Harry; Pretus, Henry; McNamee, Rose; Jones, Ernest; McLaughlin, Emily; Chandley, Wilma; Browder, William; Lowman, Douglas; and Williams, David. 1997. The Application of Various Protic Acids in the Extraction of (1 → 3)-β-D-Glucan From Saccharomyces Cerevisiae. Carbohydrate Research. Vol.299(3). 203-208. https://doi.org/10.1016/S0008-6215(97)00004-9 PMID: 9163899 ISSN: 0008-6215