Studies on nucleotides and related compounds in plants I. Isolation and identification of starch grain nucleotides

The presence of nucleotide material in whole starch grains was confirmed and the amounts of individual constituents present in a variety of starches were determined quantitatively. A rapid method for the isolation of starch grains from potato tubers to limit contamination by cell‐sap nucleotides was developed. This technique enabled reproducible nucleotide patterns to be obtained from comparable batches of starch. Of the material held by a strong anion‐exchange resin above pH 7.5, the adenine nucleotides were quantitatively dominant, only traces of UMP and GMP being detected. The relative amounts of AMP, ADP and ATP in the various starches fluctuated. ADP‐glucose was the only sugar‐containing nucleotide encountered and UDP‐glucose, although looked for, appeared to be absent in all cases.