Koichi Tateishi

Isolation of Four New Indole-3-acetic Acid (IAA) Oxidative Metabolites, a Pair of Diasteromers 5-O-β-D-glucopyranosyl 3,5-Dihydroxy-2-indolinone-3-acetic Acid and 5-O-β-D-cellobiosyl 3,5-Dihydroxy-2-indolinone-3-acetic Acid from Rice Bran

Four new metabolites related to IAA (indole-3-acetic acid) were isolated from an aqueous methanol extract of rice bran and were elucidated by spectroscopic methods to be a pair of diastereomers of 5-O-β-D-glucopyranosyl 3,5-dihydroxy-2-indolinone-3-acetic acid (A-1 and A-2) and of 5-O-β-D-cellobiosyl 3,5-dihydroxy-2-indolinone-3-acetic acid (B-1 and B-2). Compound B-1 was also a diastereomer of compound B-2 at the C3 position with an asymmetric carbon atom on an indolinone skeleton, like the relationship between compounds A-1 and A-2.

Glycogen-Surfactant Complexes : Phase Behavior in a Water/Phytoglycogen/Sodium Dodecyl Sulfate (SDS) System

The phase behavior was investigated in water/phytoglycogen/SDS and C12EO20 systems. It was found that phytoglycogen was precipitated in the presence of these surfactants. Phytoglycogen in the SDS system was dispersed more homogeneously than in the C12EO20 system, and a liquid-liquid phase separation region appeared in the SDS system. In the C12EO20 system, the transmittance of a stirred solution in the single-phase region was slightly lower than that of the phytoglycogen controls, whereas the transmittance of the stirred solution was higher than that of the controls in the SDS system. It thus seems that phytoglycogen formed a complex with SDS and that this complex affected the transmittance in the single-phase region. Viscosity measurements of the aqueous solution supported the existence of such a phytoglycogen-SDS complex. These results enabled us to propose a schematic representation of the complex structure. It was clarified that phytoglycogen forms a complex with SDS, and that the structure of the complex modifies the dispersion stability of phytoglycogen.