Ammonium 1-hydroxy-2-(2-pyridinio)ethane-1,1-diyldiphosphonate dihydrate and potassium 1-hydroxy-2-(2-pyridinio)ethane-1,1-diyldiphosphonate dihydrate.

The crystal structures of the title compounds, ammonium risedronate dihydrate, NH4+.C7H10NO7P2-.2H2O, (I), and potassium risedronate dihydrate, K+.

Mesoionic oxatriazole derivatives--a new group of NO-donors.

A number of new 3-aryl-1,2,3,4-oxatriazole-5-imine derivatives (GEA Compounds--GEAC) were synthetized. GEAC are NO-releasers as evidenced by direct measurement of NO in headspace/NO-analyzer, by cooxygenation of oxyhaemoglobin to methaemoglobin in the Werringloer's test and by generation of nitrite in the Griess' reaction. During the release of NO from GEAC the consumption of O2 could be detected only when high concentrations of GEAC were used.