a 3-oxo-Delta(1,4)-steroid + AH2 => a 3-oxo-Delta(4)-steroid + A
a 3-oxo-delta(1,4)-steroid + ah2 => a 3-oxo-delta(4)-steroid + a
a 3-oxo-Delta(1,4)-steroid + AH2 => a 3-oxo-Delta(4)-steroid + A
a 3-oxo-delta(1,4)-steroid + ah2 => a 3-oxo-delta(4)-steroid + a