The structures of two brucinium (2,3-dimeth�y-10-oxostrychnidinium) salts of the a-hydr�y acids l-malic acid and l-tartaric acid, namely brucinium hydrogen (S)-malate penta�drate, C23H27N2O4+烴H5O5-絈2O, (I), and anhydrous brucinium hydrogen (2R,3R)-tartrate, C23H27N2O4+烴H5O6-,(II), have been determined at 130 K. Compound (I) has two brucinium cations, two hydrogen malate anions and ten water mol�ules of solvation in the asymmetric unit, and forms an extensively hydrogen-bonded three-dimensional framework structure. In compound (II), the brucinium cations form the common undulating brucine sheet substructures, which accommodate parallel chains of head-to-tail hydrogen-bonded tartrate anion species in the inter�itial cavities.