The structure of daidzein was modified by sulfonation reaction. The water soluble derivatives of daidzein sodium 7-methoxy-4'- hydroxyisoflavone-3'-sulfonate (1) and cobalt (II) 7-methoxy-4'- hydroxyisoflavone-3'-sulfonate (2) have been synthesized. Their activities of anti-hypoxia and anti-anoxemia have been tested. The results show that the anti-hypoxia and anti-anoxemia activities of 1 and 2are bette than those of daidzein. The crystal of 2 {[Co~(2+) (6H_2O)][(C_(16)H_(11)O_4SO_3~-)_2]·10H_2O} belongs to triclinic space group P1-bar with cell constants a = 0.7352(2) nm, b = 0.9936(2) nm, c = 1.6301(4) nm, α = 91.21(2)°, β = 92.05(2)°, γ = 106.55(2)°, V = 1.1401(5) nm~3, Z = 1, D_c = 1.517 g/cm~3, μ = 0.566 mm~(-1), F(000) = 545, R = 0.0482, wR = 0.0806. The molecular sructure of 2 is centrosymmetrical. Co(II) is the symmetry center of 2 and octahedrally coordinated by six water molecules, of which the average Co-O bond length is 0.2060 nm. 7-Methoxy-4'-hydroxyisoflavone-3'-sulfonate anion, the six-coordinated Co(II) cation and the crystalline water molecules are linked through hydrogen bonds to form and infinite three- dimensional network. It should also be pointed out that these hydrogen bonds (and/or interaction) not only connect the cations and anions together to form a 3D-network structure, but also play a very important role in the formation, stabilization and crystallization of 2.

Key words: GLYCINE MAX, ISOFLAVONOID, SULFONIC ACID P, CRYSTAL STRUCTURE, THREE DIMENSIONAL STRUCTURE