2-Amino-5-methyl-pyridinium 2-carb-oxy-acetate

In the title mol-ecular salt, C(6)H(9)N(2) (+)·C(3)H(3)O(4) (-), the cation is essentially planar, with a maximum deviation of 0.010 (3) Å. In the anion, an intra-molecular O-H⋯O hydrogen bond generates an S(6) ring and results in a folded conformation. In the crystal, the protonated NH group and the 2-amino group of the cation are hydrogen bonded to the carboxyl-ate O atoms of the anion via a pair of N-H⋯O hydrogen bonds, forming an R(2) (2)(8) ring motif. Weak inter-molecular C-H⋯O inter-actions help to further stabilize the crystal structure.