Atropisomers of 3-substituted-4-arylquinolin-2-one derivatives having
the general formula
##STR1##
wherein R, R1, R2, R3, R4 and
R5, are as defined herein, or a non-toxic pharmaceutically acceptable
salt, solvate or prodrug thereof. The atropisomers can modulate the large conductance
calcium-activated K+ channels and are useful in the treatment of disorders
which are responsive to the opening of the potassium channels. In addition, the
atropisomers can be stable, i.e., do not interconvert, for periods of up to one
month, or more.