Synthesis of hamamelose‐diphosphate by isolated spinach chloroplasts

The branched-chain hexose hamamelose (2-C-(hydroxymethyl)D-ribose) occurs in most higher plants. Sellmair [ 1 ] and Van Scherpenberg et al. [2] found this sugar in 75 percent of 560 species of higher plants (belonging to 110 families). However, in most cases the amounts of hamamelose in the leaves were so small that detection was only possible by the isotope method of Van Scherpenberg et al. [2]. Experiments on the biosynthesis of hamamelose with whole leaves demonstrated that this sugar is formed only in the light and that its synthesis is most likely located in the chloroplasts [3,4] . The present paper shows the formation of hamamelose diphosphate by isolated spinach chloroplasts.