Fig 1: Prediction of the chemical structure of heated isomaltose. (A) Isomaltose was heated at 180 °C for 1 h, then partitioned by a dialysis membrane with a molecular weight cutoff value of 12,000–14,000. The samples were dissolved in the medium at an equivalent concentration to the heated isomaltose (100 µg/ml) and the cells were incubated in it for 24 h. The G-CSF levels in the medium were measured by ELISA and the data were shown as the absorbance. The different letters over the columns indicate significant treatment differences as determined by Dunnet’s and Dunn’s multiple t-tests (p < 0.05). Data are represented as the mean ± S.E. (n = 6). (B) HPLC chromatogram of isomaltose, heated isomaltose, and its high molecular weight fraction using size exclusion liquid chromatography. HPLC conditions: column, Inertsil WP300 Diol column (250 mm × 4.6 mm i.d., 5 μm, GL sciences, Tokyo, Japan); mobile phase, water, 0.3 ml/min; column temperature, 40 °C; injected volume, 10 μl; detector, refractive index detector RID-20A (Shimadzu). PWM pokeweed mitogen.