T. Netzer, F. Ullrich, H. Knauf
1995
Citations
0
Influential Citations
3
Citations
Journal
Handbook of experimental pharmacology
Abstract
Triamterene belongs to the class of cyclic amidine diuretics along with amiloride. The core structure of triamterene (Fig. 3) is a pteridine ring which is substituted in the 2, 4, and 7 positions by amino groups (Fig. 7). In the 6 position a phenyl moiety is connected to the pteridine structure. Triamterene shows structural similiarities to folic acid and was originally synthesized by Spickett and Timmis as a folic acid antagonist (1954). Triamterene is a yellow, odorless, crystalline powder which is almost tasteless, but has a slightly bitter aftertaste. Although its pteridine ring system is substituted by three hydrophilic amino groups, its water solubility is lower than that of the unsubstituted pteridine. This effect is explained by the formation of intermolecular hydrogen bonds between the N atoms of the amino groups and the N atoms of the pteridine structure. The high melting point of triamterene (see Table 1) is also considered to be due to formation of intermolecular hydrogen bonds. Its characteristic fluorescence (λa = 369 nm; λe = 436 nm) allows its detection in body fluids following separation with thin-layer chromatography (Grebian et al. 1976).