Yariv reactivity of Hyp-AGs. A, Hyp-AGs released from gum arabic by base treatment were purified by gel-permeation chromatography. On the basis of the comparison of the elution profiles for base-treated gum arabic (white circles) and a mixture of gum arabic and Gal (black circles), Hyp-AG fractions F2, F3, and F4 were identified. The sugar content in the fractions was determined by the phenol-sulfuric acid method. V0 and Vi indicate void volume and inner volume, respectively. B, The Yariv reactivity of F2, F3, and F4 was examined by radial diffusion assay.