Sugar composition of ergot honeydews

Abstract

Honeydews of several Claviceps spp., Sphacelia spp., and Sphacelia-like fungi were analyzed for differences in their sugar composition. Sugars were separated for comparative and preparative purposes by gel filtration and paper chromatography. The structures of pure sugars were determined with the use of periodate, enzymes, deuterium labeling, nuclear magnetic resonance spectroscopy, and methylation analysis by combined gas–liquid chromatography (glc) and mass spectrometry. Three sugars, 6 kestose, O-β-D-Fruf-(2 → 1)-O-β-D-Fruf-(2 → 6)-O-α-D-Glcp-(1 → 2)-β-D-Fruf, and O-β-D-Fruf-(2 → 6)-O-β-D-Fruf-(2 → 1)-O-α-D-Glcp-(6 → 2)-β-D-Fruf, not previously detected in ergot are reported.Sugar analysis of honeydews from infected hosts indicates that synthesis of the major sugars is controlled by the parasite and that sugar composition is distinct for each fungus. There were a number of taxonomic subgroupings that could be formed on the basis of honeydew constituents.