Dutch Elm and Elderberries

[Jane Blackburn]

I red  a while ago, some one said that elderberries (late july early august 
native) contain a chemical in their roots that besides acting as a powerfull 
laxative, will inhibite or even, as he suggested kill the fungus which 
causes dutch elm disease.  Any truth to that?  Has anyone heard of this?  It 
it is so, would planting elderberries around the roots of existing elm trees 
provide any protection?