Levcromakalim revisited: NMR spectroscopic and theoretical investigations

The conformative behaviour of the potassium channel opener levcromakalim (( -)cromakalim) was thoroughly investigated applying NMR spectroscopy in diff erent solvents as well as ab initio and DFT calculations. One predominant c onformation was found to prevail in solution. Chemical shift values (H-1, C -13) Obtained by the CIAO method employing high basis sets (B3LYP/6-311++G( **)) proved to be sensitive to conformational changes. Those correlating be st with the measured data correspond to the structure as determined by 2D N MR spectroscopy.