CHARACTERIZATION OF THE INOSITOL PENTA‐ AND HEXAPHOSPHATE FRACTIONS OF A NUMBER OF CANADIAN AND SCOTTISH SOILS

Abstract

SummaryThe nature of the inositol pentaphosphate and hexaphosphate isomers in a number of contrasting Canadian and Scottish soils has been examined.The mixed esters were extracted from the soil with alkali and separated from other soil phosphates by anion‐exchange chromatography using HCOONH4 as eluent. The composition of the mixture was established by anion‐exchange chromatography using a gradient of HC1 as eluent, followed by paper chromatography of the esters thus separated, and by paper chromatography of the hydrolysis products.Esters of myo‐ and scylloinositol together constituted more than 90 per cent of the mixture in most cases. Relatively small amounts of dl‐inositol and neoinositol were detected in hydrolysates and it was estimated that esters of these cyclitols did not exceed 10 per cent and 1 per cent, respectively, of the total. The ratio of myo‐+dl‐inositol hexaphosphates to scylloinositol hexaphosphate ranged from 1.1 to 2.7 in the Canadian soils and 1.8 to 4.6 in the Scottish soils. The ratio of hexaphosphates to pentaphosphates ranged from 0.9 to 2.4 in the Canadian soils and 3.0 to 4.3 in the Scottish soils.The three soils with the highest pH values contained relatively large amounts of scyllo‐ relative to myoinositol hexaphosphate, but one very acid soil also contained a high proportion of this isomer and no consistent relationship was noted between the constitution of the inositol polyphosphate fraction and any other soil property.