Extraction and Characterization of C. albicans β-Glucan

1,3-β-glucan were isolated from the above mentioned C. albicans as previous reported (CAG) with modification^{39 (link)}. Briefly, the cell wall was collected by centrifugation after 30 min ultrasonic fragmentation of C. albicans. After homogenization, extract with 1 M NaOH, then extract with 0.5 M acetic acid, and then wash with distilled water. Finally, the ether was used to dehydrate and dried at room temperature. The levels of CAG was measured with 1,3-β-DG ELISA kit according to manufacturer’s instructions. The structural characteristics of CAG were analysis by HPGPC, IR and NMR. IR data was obtained on a Nicolet IS5FTIR spectrophotometer using the KBr-disk method. NMR spectra were acquired with Bruker Avance-500 spectrometer and CAG was dissolved in DMSO-d₆. HPLC using pre-column derivatization with 1-phenyl-3-methyl-5-pyrazolone (PMP) was used to analyze mono-saccharides as previous described with minor revise^{22 (link)}. In brief, 5.0 mg of GAG sample was mixed with 4 mL of 2 M trifluoroacetic acid (TFA) and then stirred at 120 °C for 2 h. After removal of TFA under vacuum, the hydrolyzed products CAG were mixed with 0.5 M PMP. The obtained PMP derivatives were analyzed by HPLC on an Agilent 1200 HPLC system equipped with a C-18 column (4.6 × 250 mm, 5 μm, Agilent) and eluted with a mixture of 0.1 M phosphate buffered saline/acetonitrile (15/85) at a flow rate of 1.0 mL/min. The injection volume was 20 μL and the UV detector was set at 245 nm.