2-Amino-5-methyl­pyridinium 3-carb­oxy-4-hy­droxy­benzene­sulfonate

The asymmetric unit of the title salt, C(6)H(9)N(2) (+)·C(7)H(5)O(6)S(−), contains two crystallographically independent 2-amino-5-methylpyridinium cations and two sulfosalicylate anions. In the crystal structure, the sulfonate group of each 3-carb­oxy-4-hy­droxy­benzene­sulfonate anion inter­acts with the corresponding 2-amino-5-methyl­pyridinium cation via a pair of N—H⋯O hydrogen bonds, forming an R (2) (2)(8) ring motif. The ionic units are linked by N—H⋯O, O—H⋯O and C—H⋯O hydrogen bonds. Furthermore, the crystal structure is stabilized by π–π inter­actions between the benzene and pyridine rings [centroid–centroid distances = 3.5579 (8) and 3.8309 (8) Å]. There are also intra­molecular O—H⋯O hydrogen bonds in the anions, which generate S(6) ring motifs.