epiglucan and sulfuric-acid

β-glucan is widely distributed in nature as water soluble and insoluble forms. Both forms of β-glucan are utilized in several fields, especially for functional foods. Yeast β-glucan is a medically important insoluble particle. Solubilization of yeast β-glucan may be valuable for improving functional foods and in medicinal industries. In the present study, we applied an acid degradation method to solubilize yeast β-glucan and found that β-glucan was effectively solubilized to low-molecular weight β-glucans by 45% sulfuric acid treatment at 20°C. The acid-degraded soluble yeast β-glucan (ad-sBBG) was further fractionated into a higher-molecular weight fraction (ad-sBBG-high) and a lower-molecular weight fraction (ad-sBBG-low). Since ad-sBBG-high contained mannan, while ad-sBBG-low contained it only scarcely, it was possible to prepare low-molecular weight soluble β-glucan with higher purity. In addition, ad-sBBG-low bound to dectin-1, which is an innate immunity receptor of β-glucan, and showed antagonistic activity against reactive oxygen production and cytokine synthesis by macrophages. Thus, this acid degradation method is an important procedure for generating immune-modulating, low-molecular weight, soluble yeast β-glucan.

Topics: Animals; beta-Glucans; Binding, Competitive; Candida; Chemical Fractionation; HEK293 Cells; Humans; Lectins, C-Type; Magnetic Resonance Spectroscopy; Male; Mannans; Mice, Inbred C57BL; Molecular Weight; Oxidation-Reduction; Reactive Oxygen Species; Saccharomyces cerevisiae; Solubility; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Sulfuric Acids; Tumor Necrosis Factor-alpha