Promiscuous recognition of the hexapyranose epimers α,β-D-glucuronic and α,β-D-galacturonic acids between corrugated brucine sheets

The crystal structures of brucinium glucuronate and galacturonate are reported, both of which show layers of uronate between identical corrugated brucine sheets; the change of configuration at C(4) of the acid engineers a reversal in the packing mode of these sheets, while differences at C(1) appear to be relatively unimportant.