Radioactively Labelled Phytic Acid from Maturing Seeds of Sinapis alba

Abstract Maturing seeds of Sinapis alba were incubated with D-[U- 14 C]glucose, sodium [l- 14 C]acetate or m>>O[U- 14 C]inositol in order to prepare radioactively labelled phytic acid with high specific activity. Although each substrate was utilized for the biosynthesis of phytic acid, maximum incorporation of radioactivity into phytic acid was found with rayoinositol. Radiochemical purity of the [U- 14 C]phytic acid preparations was confirm ed by chromatographic techniques. Such preparations should be useful for the study of interaction of phytic acid with metal ions and proteins and may serve as substrate in the assay of phytase.