Abstract Quantitative structure-activity—relationships between the in vitro anti-leishmanial activity of N-benzimidazolyl-2, 4, 6-triphenylpyridinium salts 6 and pyridinium benzimidazolate betaines 7 and their 13 C-NMR chemical shifts have been studied, in order to ascertain the influence of the benzimidazole substituents upon anti-leishmanial activity. The calculated 13 C-chemical shifts allow the selection of a representative subset of ...